BIBLIOGRAPHY MARCELO, PRECIL D. APRIL 2012....
BIBLIOGRAPHY
MARCELO, PRECIL D. APRIL 2012. Effects of the Different Application Rates of
Vermicompost on the Performance of Watercress ((Nasturtium officinale Lin.).Benguet State
University, La Trinidad, Benguet.
Adviser: Jose G. Balaoing, PhD
ABSTRACT
The effects of the different application rates of vermicompost on the performance of
watercress was conducted at the BSU Organic demo farm, Benguet State University, La
Trinidad, Benguet from November 2011 to February 2012. Specifically, the study aimed to
evaluate the effects of different rates of vermicompost on the yield performance and return on
cash expense of growing watercress and to evaluate the effect of the application of vermicompost
fertilizer on some chemical properties (pH, OM and N-contents) of the soil.
The yield of watercress was not influenced by the different application rates of
vermicompost. The dry matter yield of watercress on the other hand was affected by the
application rates of vermicompost.
Increasing rates of application from 5 to 20 t ha-1 of vermicompost affected the soil
chemical properties. Application of 20 t ha-1vermicompost gave the highest mean for soil pH,
%OM and Total N.
Application of 20, 15 and 5 t ha-1vermicompost gave high returns on cash expense by
105.32%, 92.91% and 91.29%, respectively.
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INTRODUCTION
Watercress (Nasturtiumofficinale Lin.) is an aquatic plant that thrives with its
roots in water and its leaves in the sun. It is an aquatic, hardy perennial with succulent,
hollow branching stems. The creeping or floating stems root easily and bear fleshy, shiny,
heart-shaped leaves. The leaves are very dark green or bronze, with a distinctive peppery
taste. It is also tolerant to frost (Fennell, 2006).
Watercress belongs to brassicaceae family. It is known to the Philippines as
“Lampaken” and in Benguet, as “tongsoy”. It originated from western Asia but is
cultivated in Europe, United States and some parts of Asia. When traced back from the
ancient times, watercress were used by the Greeks, Romans and Persians for medical
purposes, as treatment for insanity (with vinegar), as a stimulant, and as a breath
freshener.
It is high in potassium, Vitamins A, C, and E, iron, folic acid, and calcium. It also
contains vitamin B6, which helps get blood glucose into normal level and even manganese
which is also helpful for women with osteoporosis problems.
The increase of productivity has always been the primary concern in every
agricultural and rural development efforts. Various methods and technology systems has
been employed and looked into as possible solutions to ensure high yields. However,
these methods are not always the best solutions. Most of them come at a certain price.
Certain techniques employed in ensuring high yields require high agricultural inputs such
as fertilizers and pesticides. These imposed additional cost that burdens small farmers.
The use of chemical fertilizers and pesticides tend to strip the soil of its natural nutrients,
thereby causing environment to degrade (Lim, 2002).
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Due to its economic and health importance, watercress production must be
encouraged for small farmers for additional income. This must be done through the
organic way of farming.
This study then serves as a guide for organic growers in the use of appropriate and
effective organic fertilizers as well as the proper management techniques in the
production of watercress without degrading the environment while sustaining agricultural
production.
The study focused on the effects of different application rates of vermicompost on
the performance of watercress (Nasturtium officinale Lin).
Specifically, the study was conducted to 1) evaluate the effects of different rates
of vermicompost on the yield performance and return on cash expense of growing
watercress and 2) evaluate the effect of the application of vermicompost fertilizer on
some chemical properties (pH, OM and N-contents) of the soil.
The study was conducted at the Organic Demo Farm experimental area,
Department of Soil Science, College of Agriculture, Benguet State University La
Trinidad Benguet from November 2011 to February 2012.
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REVIEW OF LITERATURE
Importance of Growing Watercress
Orwell (2011) said that watercress contains gluconasturin, a unique type of
phytochemical that is converted into PEITC (2- phenyl ethyl isothiocyanate), a volatile
compound sensitive to heat and moisture and is found to inhibit the growth of a number
of different kinds of cancer including breast cancer, colon, and prostate cancers.
In addition, the BBC website as cited by Bramwell (2010) reported that a study
published in American Journal of Clinical Nutrition found that eating watercress reduces
DNA damage in white blood cells.
Conventional Agriculture
Eicher(2003) defined Conventional agricultureasan industrialized agricultural
system characterized by mechanization, monocultures, and the use of synthetic inputs
such as chemical fertilizers and pesticides, with an emphasis on maximizing productivity
and profitability.
In these modern times, agriculture is becoming more and more dependent upon
the steady supply of artificial fertilizers and pesticides with the introduction of green
revolution techniques (Singh, 2009). However, these conventional farming which our
farmers had adopted brought lots of negative effects to the different aspects of human
life. Panganiban (2006) as cited by Macaroy (2007) also said that over the last years, the
reckless use of resources and the dependence on chemical based pesticides and fertilizers
had harmful and possibly permanent effects on the environment.
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The persistent use of chemical fertilizers causes the pollution of ground water
sources, or leaching. They are highly soluble being absorbed by the ground more rapidly
than the intended plants. Plants have the capacity to absorb only a given level of nutrition
at a time leaving the rest of the fertilizer to leach. Leaching is not only hazardous to
groundwater sources but also to the health of subsoil where these chemicals react with
clay to create hard layers of soil known as hardpan (Sarfaras, 2011).
The synthetic chemicals in the chemical fertilizers adversely affect the health of
naturally found soil micro-organisms by affecting the soil pH. These altered levels of
acidity in the soil eliminate the micro-organisms beneficial to plant and soil health as they
help to increase the plants' natural defenses against pests and diseases. The use of
chemical fertilizers affects the health of bacteria that fix the nitrogen balance in the soil
(Sarfaras, 2011).
Given this picture, going back to Organic Agriculture which had long been
practiced in the olden times should be the priority of today’s agriculture. The use of
sustainable practices which ensures high productivity and profitability without degrading
the environment must be taken into consideration.
Organic Agriculture
Organic Agriculture is a type of farming system that promotes the use of
renewable resources and management of biological cycles to enhance biological diversity
without the use of genetically modified organisms or synthetic pesticides, herbicides and
fertilizers for the production of plants as well as the refrain from using synthetic food
stuffs, growth hormones and antibiotics for the production of animals (Eicher, 2003).
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It is also defined by the USA’s National Organic Standards Board (1996) as cited
by Balaoing (2010) as an ecological production management system that promotes and
enhances biodiversity, biological cycles and soil biological activities.
IFOAM(2005) as cited by Asian Development Bank Institute (2011) defines
organic agriculture as a “holistic production management system which promotes and
enhances agro-ecosystem health, including biodiversity, biological cycles, and soil
biological activity. It emphasizes the use of management practices in preference to the
use of off-farm inputs, taking into account that regional conditions require locally
adapted systems.”
Organic production relies on management techniques that maintain and replenish
the long term soil fertility by optimizing the soil’s biological activity. These are achieved
through crop rotation, cover cropping, use of compost and any organically accepted
fertilizers that feed the soil while providing the plants with nutrients (Guerena, 2006).
Environmental Benefits of Organic Agriculture
Organic farming protects our water supply in a way that it bans artificial
fertilizers to pollute water supply, it preserves healthy soils, prevents biodiversity loss,
supports sustainable practices, saves energy and less fossil fuels, it also nurtures and
protects wildlife and lastly, it helps maintain our rural communities in a way that organic
farmers are independent and small in size that represents one of the few readily available
and viable strategies for the survival of rural communities (Balaoing, 2010).
Food and Agriculture Organization (2011) also said that organic agriculture
benefits the soil by encouraging soil fauna and flora thus improving soil formation and
structure and creating more stable systems. In turn, nutrient and energy cycling is
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increased and the retentive abilities of the soil for nutrients and water are enhanced,
compensating for the non-use of mineral fertilizers. Greater biodiversity which is
employed in organic agriculture enhances soil structure and water infiltration. Properly
managed organic systems with better nutrient retentive abilities greatly reduce the risk of
groundwater pollution.
Organic agriculture as well reduces non-renewable energy use by decreasing
agrochemical needs. It contributes to mitigating the greenhouse effect and global
warming through its ability to sequester carbon in the soil. Many management practices
used by organic agriculture increase the return of carbon to the soil, raising productivity
and favoring carbon storage. The impact of organic agriculture on natural resources
favors interactions within the agro-ecosystem that is vital for both agricultural production
and nature conservation. Ecological services derived include soil forming and
conditioning, soil stabilization, waste recycling, carbon sequestration, nutrients cycling,
predation, pollination and habitats. By opting for organic products, the consumer through
his/her purchasing power promotes a less polluting agricultural system. The hidden costs
of agriculture to the environment in terms of natural resource degradation are reduced.
Benefits of Adding Organic Matter to the Soil
Organic matter is a reservoir of nutrients that can be released to the soil. Each
percent of organic matter in the soil releases 20-30 pounds of N, 4.5-6.6 pounds of P2 O5
and 2-3 pounds of sulfur per year. Organic matter also absorbs and holds up to 90% of its
weight in water which is released for plant absorption. It causes soil to clump and form
aggregates which improves soil structure. With better soil structure, permeability
Effects of the Different Application Rates of Vermicompost on the Performance of
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improves in turn, improving the soils ability to take up and hold water. Lastly, organic
matter prevents erosion (Funderburg, 2011).
MacRae and Mehuys (1990) added that organic matter plays more of a role in
aggregate stability than in aggregate formation. It is, in fact, the primary stabilizing agent
for aggregates in temperate-area soils. This stabilization process is accomplished mainly
through the by-products of organic matter decomposition (microbial gums and
mucilages). Organic matter also decreases the bulk density of soil.
The humus added to soil by organic fertilizers helps stabilize soil aggregates,
improving tilth. It helps separate the particles in clay soil, which makes the soil looser
and easier to work as well as easier for roots to penetrate. In sandy soil, humus acts as a
binder to hold particles together so they don't wash away from the plants' roots, and it
improves moisture retention. Humus and compost condition the soil, adds nutrients and
improves the water retention properties. Healthy, organic soil has sponge-like properties
that enhance the movement of water through the soil. Increased soil moisture aids
microbes as they convert nutrients into a form plants can use, and it keeps those nutrients
suspended so they are readily available for uptake by plants' root systems. Organic
fertilizers supply natural sources of nutrients that microbes can process easily (Fischer,
2010).
Vermi Compost
Sundaram Overseas Operation (2008) said that vermi compost enriches the soil in
most natural organic manner and also increases the quality, fertility and mineral content
of the soil. As compared to chemical fertilizers, organic fertilizer is completely harmless
and provides rich organic soil that is best for plants while chemical fertilizers destroy
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beneficial microorganisms. In addition, vermi compost contains more than eight kinds of
useful microbial bacterium groups (over 600 million per gram) wherein it can supply all
nutrition elements needed by variety of plants.
Liquid Organic Fertilizer
Zulueta (1982) as cited by Tomin (2011) said that Liquid organic fertilizers play
an important role in plant growth particularly leafy vegetable crops. It gives a very
important source of mineral elements and food for the plant. It has been extensively used
in irrigated lands for direct application to crops.
Organic Products
Organic crops differ in nutrient content from conventional crops. Organic crops
contained significantly more vitamin C, iron, magnesium, and phosphorous and
significantly less nitrates. These were significant trends showing less protein but of a
better quality and higher content of nutritionally significant minerals with lower amounts
of some heavy metals in organic crops compared to conventional ones (Worthington,
2001).
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MATERIALS AND METHODS
The materials used in the research experiment were stem cuttings of watercress of
similar length (3 inches) and maturity, vermicompost which was obtained from the BSU
Organic Demo Farm, liquid organic fertilizer derived from 13 kg chopped banana trunk;
13 kg chopped wild sun flower and 1 L molasses fermented for 7-10 days, identifying
tags which was used for treatment identification and farm implements such as sickle,
cultivator, and hoes.
A total land area of 50 m2 was thoroughly prepared following watercress culture
production. Puddling the soil for the purpose of water conservation and maintenance is
necessary to grow watercress in the area. The area was divided into four (4) blocks with
each block having five (5) treatment plots measuring 1mx2m each. Border plot of at least
1 foot width was used to separate each treatment to avoid contamination. Each treatment
was planted with 2 kg of watercress stem cuttings after the application of vermicompost
following the different rates studied.
Application of the different amounts of vermicompost were done by thoroughly
incorporating this a week before planting.
Blanket application of liquid organic fertilizer of about 500 ml diluted LOF
derived from fermented 13 kg chopped banana trunk, 13 kg chopped wild sunflower and
1 L molasses was applied 1 week after planting at an interval of 7 days.
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Figure 1. Field layout of the experimental area located at the BSU
organic demo farm, La Trinidad, Benguet
Figure 2. Fermented chopped sunflower, banana trunk and molasses as
liquid organic fertilizer
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The following treatments studied were as follows:
C1 = No fertilizer input + Liquid Organic Fertilizer
C2 = 5 tons/ha vermicompost + Liquid Organic Fertilizer
C3 = 10 tons/ha vermicompost + Liquid Organic Fertilizer
C4 = 15 tons/ha vermicompost + Liquid Organic Fertilizer
C5 = 20 tons/ha vermicompost + Liquid Organic Fertilizer
The different treatments were laid out in the experimental area following the
Randomized Complete Block Design (RCBD) with four (4) replications.
The data gathered were:
1. Fresh weight of water cress at harvest
Staggered harvesting of watercress was done throughout the conduct of the study.
This was marketed into one-fourth (1/4) kg or 250 g labeled as organic product at the
BSU Organic Market.
2. Dry matter yield
This was gathered by weighing twenty grams of watercress separately for each
treatment and was cut into pieces. It was oven dried for 24 hours. This was recorded and
computed using the following formula:
Dry matter = 100% - % Moisture Content
Where: % Moisture Content = FW – ODW x 100
ODW
3. Insect Pest Incidence
The plants were observed and the occurrence of insect pests was noted. The
insects that attacked the watercress and the damage they caused was monitored and
Effects of the Different Application Rates of Vermicompost on the Performance of
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recorded. The arbitrary rating scale used by Halog and Molina (1981) is shown
below.
Scale
Description
1
Sound, leaves with no damage
2
Slight, 1-3 leaves affected
3
Moderate, 4-6 leaves affected
4
Severe, most of the leaves affected
5
Skeletonized, all leaves affected
4. Disease Incidence
The plants were observed and the occurrence of diseases was recorded. Diseases
were rated using the arbitrary rating scale used by Lasilas, (2010) asshown below.
Scale
Description
1
No infection
2
1-25% of the total plant
3
26-50% of the total plant
4
51-71% of the total plant
5
76-100% of the total plant
5. Soil Analysis- Soil samples were collected before planting and after harvest for the
following analysis using PCCARD standard method:
a. Soil pH. This was determined using 1:2.5 CaCl2 soil suspension. A 10 g of air
dried soil was weighed into a 100 ml beaker. Then 25 ml of 0.01 M CaCl2 was added and
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stirred thoroughly and periodically for 15 to 20 minutes. The pH meter was calibrated
with the standard buffer solution. The electrode of pH meter reading was recorded.
b. Organic matter content of the soil (%). One gram of oven dried soil was placed
in a 250 ml conical flask. Then 10 ml of 1N K2 Cr2 O7 was added followed by an
immediate and rapid addition of concentrated H2SO4. The soil solution was mixed gently
and it was allowed to be digested in the fume hood. After digestion, 250 ml of distilled
water was added. Concentrated H3BO3 and 1.0 ml of diphenylamine indicator solution
was added to the filtrate. The solution was titrated with standard 0.5 N FeSO4. Titration
was stopped when the initial color of yellowish brown changed from blue to violet to
green abruptly. The green color indicated the end point. A blank sample was prepared
following the same procedure except that no soil will be added. The % Organic matter
was computed using the formula:
% OM = 10(S-T) x 0.0069 x 100
S wt. of soil sample
Where S = ml of ferrous solution required for blank
T = ml of ferrous solution required for sample
c. Nitrogen Content of the Soil (%). The Nitrogen content of the soil was
computed by multiplying the OM content by 0.05.
6. Return on Cash Expenses
This was done by recording all the expenses and production rates. It was
computed using the formula;
ROCE (%) = Gross income – Total Expensesx 100%
Total Expenses
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RESULTS AND DISCUSSION
Yield of Parameters of Watercess as Affected by
the Different Application Rates
ofVermicompost
Yield per Plot
Table 1 shows the watercress yield per plot as affected by the different rates of
vermicompost. There were no significant differences obtained in the analysis. However,
plant grown from those applied with 20 t ha-1vermicompost had the highest yield of 4.14
kg per plot. Untreated plots registered the lowest yield of 3.033 kg per plot. This implies
that application of vermicompost enhances yield of watercress.
Dry Matter Yield
The dry mater yield of watercress as affected by the different application rates of
vermicompost is shown in Table 2. Plants grown from those applied with 20 t ha-1, 15
Table 1. Yield per plot as affected by the different application rates of vermicompost.
TREATMENT
MEAN
C1
=
Control
3.033a
C2
=
5tons/ha
VC
+
LOF
3.405a
C3
=
10tons/ha
VC
+
LOF
3.155a
C4
=
15tons/ha
VC
+
LOF
3.743a
C5
=
20
tons/ha
VC
+
LOF
4.148a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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t ha-1 and 10 t ha-1vermicompost had the highest mean of 8.55 g, 7.225g, and 7.705 g
respectively. Plants grown from those untreated plots gave the lowest mean of 4.725 g.
The result implies that application of vermicompost enhances the dry matter yield of
watercress. This confirms the study of Azarmiet. al. (2008) wherein application of
vermicompost at the rate of 15 t ha-1 increases the dry matter yield of tomato fruit by
24%.
Pest Infestations as Affected by the
Different Application Rates
ofVermicompost
Snail Infestation
Table 3 shows the ratings of snail infestations of watercress as affected by the
different application rates of vermicompost. Plants treated with 10 t ha-1vermicompost
Table 2.Dry matter yield of watercress as affected by the different application rates of
vermicompost.
TREATMENT
MEAN
C1
=
Control
4.725bc
C2
=
5tons/ha
VC
+
LOF
6.625b
C3
=
10tons/ha
VC
+
LOF
7.705a
C4
=
15tons/ha
VC
+
LOF
7.225a
C5
=
20
tons/ha
VC
+
LOF
8.550a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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significantly had the highest rate of 3.75 snail infestation. Lowest rate of snail infestation
was noted from those plants applied with 5 t ha-1vermicompost.
Flee Beetle Infestation
Flee Beetle infestation as shown in Table 3 showed that highest rate of 2.25
(Slight damage) snail infestation was observed from untreated plots while lowest rate of
1.125 (no damage) was noted from plants applied with 20 t ha-1vermicompost.
Cabbage Worm
Cabbage worm infestation (Figure 3) showed no significant differences (Table 3).
However, highest rate of infestation which is 1.186 (no damage) was observed from
plants treated with 5 t ha-1vermicompost and the lowest rate which is 1 (no damage) was
noted from both plants applied with 15 t ha-1 and 20 t ha-1vermicompost.
Table 3.Pest infestations of watercress as influenced by the different application rates of
vermicompost.
TREATMENT
______RATE OF PEST DAMAGE______
SNAIL FLEEBEETLE CABBAGE
WORM
C1
=
Control
1.50bc
2.25a
1.125a
C2 = 5tons/ha VC + LOF
1.25b
1.375a
1.186a
C3 = 10tons/ha VC + LOF
3.75a
1.438a
1.125a
C4 = 15tons/ha VC + LOF
1.75b
1.375a
1.000a
C5 = 20 tons/ha VC + LOF
2.00b
1.125a
1.000a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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Disease Incidence of Watercress as Affected
by the Different Application Rates
ofVermicompost
Aster Yellow Infection
Statistics revealed no significant differences in the infestation of aster yellow
disease of watercress (Figure 3) as influenced by the different application rates
ofvermicompost (Table 4). However, highest rate of infestation were observed from
untreated plants, plants applied with 5 t ha-1, and 15tons ha-1vermicompost having a mean
of 1.75%. Lowest rate of 1.25% was noted from plants applied with 20 t ha-
1vermicompost. Aster yellow is one among the serious diseases of watercress production
(McHugh, 2012).
Table 4. Aster yellow disease of watercress as affected by the different application rates
of
vermicompost.
TREATMENT
MEAN
C1
=
Control
1.75a
C2
=
5tons/ha
VC
+
LOF
1.75a
C3
=
10tons/ha
VC
+
LOF
1.50a
C4
=
15tons/ha
VC
+
LOF
1.75a
C5
=
20
tons/ha
VC
+
LOF
1.25a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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Figure 3. Aster yellow disease and cabbage worm infestation
Some Chemical Properties of the Soil
Initial Properties of the Soil
The initial properties of the soil were analyzed before planting (Table 5). The
initial pH of the soil was 5.7 indicating that the soil is slightly acidic. The nitrogen
content and organic matter content were 0.12% and 2.56% respectively. The initial pH of
the soil is low in terms of the favorable soil pH for watercress production which is neutral
or 7.0 (McHugh, 2012). Organic matter content on the other hand is slight low and it did
not reach the range for mineral surface soils which is 3-5% by weight (Brady, 1985). This
implies that application of organic fertilizer is necessary to supplement the soil.
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Table 5.Initial Soil Properties.
PROPERTY
CONTENT
A. Chemical Properties
1. pH
5.7
2. N
(%)
0.12
3. OM
(%)
2.56
Final Soil pH
Table 6 shows the final pH of the soil as affected by the different application rates
of vermicompost. An increase on the soil pH was noted from vermicompost application
from the initial soil pH of 5.7. Plots applied with 5, 10, 15 and 20 t ha-
1vermicompostgave corresponding increases of 17.37%, 17.54%, 21.58%, and 26.00%
respectively overthe initial pH value of 5.70. Likewise, an increase of 14.04% was
observed from plots without vermicompost application. The observation can be attributed
to the ability of the organic material to buffer changes in soil pH.
Organic Matter Content of the Soil
Organic matter content of the soil was influenced by the application rates of
vermicompost (Table 7). There were observed increase of the organic matter contents of
the soil where vermicompost was applied from 5 to 20 t ha-1 over the initial value of
2.56%.
Moreover, statistical analysis showed highly significant differences among the
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20
treatments. Plots applied with 20, 15, 10, and 5 t ha-1vermicompost differ at about
98.47%, 97.55%, 89.26%, and 53.68% respectively over the control. An increase in
theOM content in the control plots as compared to the initial (2.56%) could be attributed
to the blanket application of Liquid organic fertilizer. Results implied that increasing the
rate of application for vermicompost increases the organic matter content of the soil.
Arancon and Edwards (2005) said that the application of vermicompost in the field
enhances the quality of soils by increasing microbial activity and microbial biomass
which are key components in nutrient cycling, production of plant growth regulators and
protecting plants soil-borne disease and arthropod pest attacks.
Table 6. Soil pH as affected by the different application rates of vermicompost.
TREATMENT
MEAN
C1
=
Control
6.50e
C2
=
5tons/ha
VC
+
LOF
6.70d
C3
=
10tons/ha
VC
+
LOF
6.70c
C4
=
15tons/ha
VC
+
LOF
6.93b
C5
=
20
tons/ha
VC
+
LOF
7.00a
Initial
5.70
Means followed by a common letter /s in a column are not significantly different at 0.05
level by DMRT.
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Table 7.Organic matter content of the soil as affected by the different application rates of
vermicompost.
TREATMENT
MEAN
C1
=
Control
3.26c
C2
=
5tons/ha
VC
+
LOF
5.01c
C3
=
10tons/ha
VC
+
LOF
6.17b
C4
=
15tons/ha
VC
+
LOF
6.44a
C5
=
20
tons/ha
VC
+
LOF
6.47a
Initial
2.56
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT
Total Nitrogen Content of the Soil
Total nitrogen of the soil was influenced by the application of different rates of
vermicompost (Table 8). Application of increasing rates of vermicompost affected
thetotal nitrogen content of the soil as compared to the initial which is 0.12%. An
increase of 33.33%, 116.67%, 158.33%, 166.67% and 191.67% was observed from plots
treated with 5, 10, 15 and 20 t ha-1vermicompost respectively.
Likewise, application of 20, 15, 10, and 5 t ha-1vermicompost differ at about
118.75%, 100%, 93.75% and 62.50% respectively over the control.
An increase in the total nitrogen in the untreated plants having 0.16% as
compared to the initial (0.12%) could be attributed to the blanket application of liquid
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
22
Table 8.Total Nitrogen content of the soil as affected by the different application rates of
vermicompost.
TREATMENT
MEAN
C1
=
Control
0.16c
C2
=
5tons/ha
VC
+
LOF
0.26c
C3
=
10tons/ha
VC
+
LOF
0.31b
C4
=
15tons/ha
VC
+
LOF
0.32a
C5
=
20
tons/ha
VC
+
LOF
0.35a
Initial
0.12
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT
organic fertilizer. This implies that increasing rates of vermicompost increases total
nitrogen of the soil.
Economic Importance
Return on Cash Expenses
The return on cash expenses of watercress as affected by the different application
rates of vermicompost is shown in Table 9. Plants applied with 20 tha-1vermicompost
gave the highest ROCE of 105.32%. This implies that for every 1 peso investment, there
is a 105.32 return of investment. Plots applied with 15 and 5 tha-1vermicompost on the
other hand have a peso investment return of 92.91 and 91.29 respectively. Lowest ROCE
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
23
was noted from untreated plants and plants applied with 10 tha-1vermicompost having
78.38% and 69.62% respectively.
Plots applied with 10 t ha-1 which has the lowest ROCE was attributed to the
attack of snails which had caused major damage to the plants as shown in Table 7.
Table 9. Cost and return analysis of watercress applied with the different application
rates of vermicompost.
TREATMENT Yield
/2m2 GROSS
COST
OF NET
%ROCE
(kg)
INCOME
PRODUC-
INCOME
(Php)
TION
(
Php)__(Php)
_____________
C1
12.13
1,213
680
533
78.38
C2
13.62
1,362
712
650
91.29
C3
12.62
1,262
744
518
69.62
C4
14.97
1,497
776
721
92.91
C5
16.59
1,659
808
851
105.32
Price was computed at Php100/kg.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
24
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at the BSUOrganic Demo Farm, Benguet State
University, La Trinidad, Benguetfrom November 2011 to February 2012.The study was
conducted to: 1) to evaluate the effects of different rates of vermicompost on the yield
performance and return on cash expense of growing watercress and 2) to evaluate the
effect of the application of vermicompost fertilizer on some chemical properties (pH, OM
and N-contents) of the soil.
The different application rates of vermicompost did not influence the total yield of
watercress. However, the dry matter yield of watercress was affected by the application
of vermicompost.
The initial soil pH was increased with the increasing rates of vermicompost to a
favorable pH for watercress production. Percent OM and total N content of the soil
however, is at the optimum level and it is most likely sufficient for plant growth.
Application of vermicompost tend to increase these soil chemical properties because
plants treated with the highest rate of vermicompost gave the highest value for soil pH
and both % OM and % N.
The return on cash expense (ROCE) showed that high returns were obtained from
plants grown in plots applied with 20, 15 and 5 tons ha-1vermicompost having 105.52%,
92.91% and93.29%respectively.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
25
Conclusion
Based on the results of the experiment, the following conclusions were drawn:
1. Increased application rates of vermicompost influenced the chemical properties
of soil studied thus is effective in increasing the yield of watercress. However, the yield
increase based on the different application rates of vermicompost was not significant.
2. Vermicompostapplication of 5, 15 and 20 t ha-1 gave high economic benefits
compared to the control.
Recommendation
Application of either 20 tha-1 or 15 tha-1vermicompost is recommended as best
application rates for growing watercress. Further study however, is recommended to
verify the results.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
26
LITERATURE CITED
ARANCON, N.Q. and EDWARDS, C.A. 2010. Effects of vermicomposts on plant
growth. Retrieved March 18, 2012 from http://www.slocountyworms.com/wp-
content/uploads/2010/12/effects-of-vermicomposts-on-plant- growth.pdf
ASIAN DEVELOPMENT BANK IINSTITUTE. 2011. Organic agriculture and
certification: an over view. Retrieved October 3,
2011, from http://www.adbi.
org/discussion-paper/2008/08/25/2675.organic.fairtrade.certification/organic.
agriculture.and.certification.an.overview/
AZARMI, R. PARVIS, S.V. and MOHAMMAD, R.S. 2008. Effect of vermicompost on
growth, yield and nutrition status of tomato (Lycopersicumesculentum).
Retrieved March 18,2012 fromhttp://scialert.net/fulltext/?doi=pjbs.2008.1797.
1802
BALAOING, J.G. 2010.Technologies in organic agriculture. Lecture Presented in
Bontoc,
Mt.
Province
BRADY, N.C. 1985. The nature and properties of soils.McMilan Publishing Company,
Pp. 15 and 50.
BRAMWELL, A. 2010.Watercress growing requirements. Retrieved June 6, 2011, from
http://www.ehow.com/list_7553806_growing-
requirements.html:
EICHER, A. 2003.A glossary of terms for farmers & gardeners. Retrieved June 10,
2011,
from
http://ucce.ucdavis.edu/files/filelibrary/1068/8286.pdf
FOOD AND AGRICULTURE ORGANIZATION. 2011. What are the environmental
benefits of organic agriculture?
Retrieved
September 29, 2011, from
http://www.fao.org/organicag/oa-faq/oa-faq6/en/
FENNELL, J.F. 2006.Potential for watercress production in Australia.Retrieved June
6, 2011, from http://www.rirdc.infoservices.com.au/downloads/06-105.pdf
FISCHER, F. 2010. The effects of organic fertilizer. Retrieved October 04, 2011, from
http://www.livestrong.com/article/256216-the-effects-of-organic- fertilizer/
FUNDERBURG, E. 2011. What does organic matter do in soil? The Samuel
Roberts noble foundation. Retrieved June 6, 2011, from
http://www.noble.org/Ag/Soils/organic matter/index.htm
GUERENA, M. 2006. Cole crops and other Brassicas: AT TRA Organic production.
Retrieved June 6, 2011, from http://74.6.117.48/search/srpache?ei=UTF-
8&p=organic+production+of+watercress&rd=r1&meta
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
27
HALOG, J.M. and L.R. MOLINA. 1981. Field and greenhouse study on the biological
control of diamond backmoth of cabbage using bactospeine and dipel. BS Thesis.
Benguet State University, La Trinidad Benguet.P.26.
LASILAS, N.L. 2010. Status of virus infection in Potato variety Igorota and its
implication to the informal seed system. BS Thesis. Benguet State University, La
Trinidad
Benguet.P.16.
LIM, A. K. 2002. Natural farming technology seminar. Lecture presented in
La
Trinidad,
Benguet.
MACAROY, J. 2007. Production and marketing practices of the members of the La
Trinidad Organic Practitioners in La Trinidad Benguet. BS Thesis. Benguet State
University. La Trinidad Benguet.P. 4.
MACRAE, R.J. and G.R. MEHUYS. 1990. The effect of green manuring on the physical
properties of temperate-area soils. Retrieved October 04, 2011, from
http://www.sarep.ucdavis.edu/NEWSLTR/v2n4/sa-5.htm
McHUGH, J.J. 2012.Crop profile for watercress in Hawaii. Retrieved March 12, 2012,
from http://www.ipmcentres.org/cropprofiles/docs/HIwatercress.pdf
McHUGH, J.J. and CONSTANTINIDES, L.N. 2004.Pest management strategic plan for
watercress production in Hawaii. Retrieved March 14, 2012, from
http://www.ipmcenters.org/pmsp/pdf/HIwatercress.pdf
ORWELL, M. 2011. Health benefits of watercress. Retrieved June 6, 2011, from
http://www.Ehow.com/facts_4780289_health-benefits-watercress.htm
SARFARAS, I. 2011. The effects of chemical fertilizers on soil. Retrieved October 04,
2011 from http://www.ehow.com/list_6603980_effects-chemical-fertilizers-
soil.html#ixzz1ZnW6FCqZ
SUNDARAM OVERSEAS OPERATION. 2008. Vermi compost fertilizer. Retrieved
March 25, 2011, from http://www.soo.coin/fertilizer.htm
SINGH, A. 2009.Hazardous effects of chemical fertilizers and pesticides. Retrieved
June 10, 2011, from http://andamanchronicle.com/content/view/1627/62/
TOMIN, G. 2011. Rates of vermi compost and frequency of sunflower extract
application on some soil properties and performance of French beans
(Phaseolus vulgaris L.)BS Thesis. Benguet State University, La Trinidad
Benguet.P.
9.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
28
WORTHINGTON, V. 2001.Nutritional quality of organic vs. conventional fruits,
vegetables and grains. The Journal of all alternative and complementary
medicine . Retrieved June
10, 2011, from
http://www.chiro.org/
nutrition/FULL/Nutritional_quality_oforganic _versus_convebtional
_fruits_htm
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
29
APPENDICES
Appendix Table 1. Yield per plot (kg/2m2)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
1.45 4.28 3.51 2.89 12.13
3.033
C2
4.37 3.63 2.13 3.49 13.62
3.405
C3
3.28 2.36 2.80 4.18 12.62
3.155
C4
3.34 4.62 3.45 3.56 14.97
3.743
C5
3.72 5.01 4.35 3.51 16.59
4.148
TOTAL
16.16 19.9 16.24
17.63 69.93 17.484
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
1.83
0.61
TREATMENT 4
3.30 0.825
1.06ns
3.26 5.41
ERROR
12
9.34 0.778
TOTAL 19
14.47
2.21
ns
-
Not
Significant
%CV=
5.04
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
30
Appendix Table 2. Dry matter yield (g)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
4.4
4.5 4.9
5.1
18.9
4.725
C2
6.3
8.4 6.0
5.8
26.9
6.625
C3
8.7
5.7 7.2
6.6
28.2
7.050
C4
5.7
8.1 8.0
7.1
28.9
7.225
C5
9.1
8.3 8.6
8.2
34.2
8.550
TOTAL
34.2 35 34.7 32.8 137.1
34.175
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.574
0.191
TREATMENT 4
30.55 7.638
7.03** 3.26 5.41
ERROR
12
13.05 1.087
TOTAL
19
44.17
8.916
**-
Highly
Significant
%CV=
3.05
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
31
Appendix Table 3. Snail’s infestation on watercress
TREATMENT
BLOCK
TOTAL MEAN
I
II III
IV
C1
1
2
2
1 6
1.50
C2
1
1
2
1 5
1.25
C3
2
5
4
3
15
3.75
C4
1
3
1
2
7
1.75
C5
2
2
1
3
8
2.00
TOTAL
8 13 10
10 41 10.25
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
2.55
0.85
TREATMENT 4
15.7 3.93
7.02**
3.26 5.41
ERROR
12
6.7 0.56
TOTAL
19
44.17
5.34
**-
Highly
Significant %CV=
7.30
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
32
Appendix Table 4. Flee Beetle infestation on watercress
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
2.00 1.75 2.00
1.00
6.75
2.250
C2
1.75 1.00 1.25
1.50
5.50
1.375
C3
1.00 2.00 1.75
1.00
5.75
1.438
C4
1.75 1.00 1.00
1.75
5.50
1.375
C5
1.00 1.50 1.00
1.00
4.50
1.125
TOTAL
7.50 7.25 7.00 6.25 28.00 7.563
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.175
0.058
TREATMENT 4
0.644 0.161
0.82ns
3.26 5.41
ERROR
12
2.356 0.196
TOTAL
19
44.17
0.415
ns
-
Not
Significant
%CV=
5.85
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
33
Appendix Table 5. Cabbage worm infestation on watercress
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
1
1
1 1.5
4.5
1.125
C2
1
1
1 1.75
4.75
1.186
C3
1
1
1 1.5
4.5
1.125
C4
1
1
1 1
4
1.00
C5
1
1
1 1
4
1.00
TOTAL
5
5
5 6.75 21.75 5.436
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.463
0.154
TREATMENT 4
0.116 0.029
1.04ns 3.26 5.41
ERROR
12
0.3340.028
TOTAL
19
0.913
0.211
ns
-
Not
Significant
%CV=
3.08
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
34
Appendix Table 6. Aster yellow disease infestation on watercress (%)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
1
2
1
3
7
1.75
C2
1
2
2
2
7
1.75
C3
1
1
1
3
6
1.50
C4
1
2
1
3
7
1.75
C5
1
1
2
1
5
1.25
TOTAL
5
8
7
12
32
8
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
5.2
1.73
TREATMENT 4
0.8
0.20
0.5ns
3.26 5.41
ERROR
12
4.8 0.40
TOTAL
19
44.17
2.30
ns
-
Not
Significant
%CV=
8.84
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
35
Appendix Table 7. Soil pH
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
6.55 6.43
6.54 6.46
25.98
6.495
C2
6.73 6.72 6.65 6.67
26.77
6.693
C3
6.73 6.67 6.71 6.70
26.81
6.703
C4
6.76 7.01 6.96 6.98
27.71
6.928
C5
6.93 7.00 7.08 6.97
27.98
6.995
TOTAL
33.7 33.83 33.94 33.78 135.25 33.813
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.0042 0.0014
TREATMENT 4
0.6435 0.1609
30.36**
3.26 5.41
ERROR
12
0.0634 0.0053
TOTAL
19
0.711
0.1676
**
Highly
Significant
%CV=
0.21
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
36
Appendix Table 8. Organic matter content of the soil (%)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
3.08 3.18
3.38 3.28
13.02
3.26
C2
4.47 5.86 5.26 4.96
20.05
5.01
C3
6.25 6.06 6.16 6.21
24.68
6.17
C4
6.50 6.40 6.42 6.43
25.75
6.44
C5
6.21 6.55 6.75 6.35
25.86
6.47
TOTAL
26.61 28.05 27.97 33.78 109.36 27.35
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.362
0.121
TREATMENT 4
30.72 7.532
73.126** 3.26 5.41
ERROR
12
1.241 0.103
TOTAL
19
32.323
7.756
**-
Highly
Significant %CV=
1.17
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
37
Appendix Table 9. Total nitrogen content of the soil (%)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
0.16 0.16
0.17 0.16
0.65
0.16
C2
0.22 0.29 0.26 0.25
1.02
0.26
C3
0.31 0.30 0.31 0.31
1.23
0.31
C4
0.33 0.32 0.32 0.32
1.29
0.32
C5
0.31 0.33 0.38 0.32
1.34
0.35
TOTAL
1.33 1.40 1.44 1.36 5.53 1.40
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.001 0.0003
TREATMENT 4
0.080 0.0200
50.00**
3.26 5.41
ERROR
12
0.005 0.0004
TOTAL
19
0.086
0.0207
**
-
Highly
Significant %CV=
1.43
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
38
Appendix Table 10. Return on cash expenses
TREATMENT Yield
/Plot
GROSS COST
OF
NET
%ROCE
(kg)
INCOME
PRODUC-
INCOME
(Php)
TION
(
Php)__(Php)
_____________
C1
12.13
1,213
680
533
78.38
C2
13.62
1,362
712
650
91.29
C3
12.62
1,262
744
518
69.62
C4
14.97
1,497
776
721
92.91
C5
16.59
1,659
808
851
105.32
Price used in the computation of gross income is Php 100.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
TABLE OF CONTENTS
Page
Bibliography…………………………………………………………………….. i
Abstract…………………………………………………………………………
i
Table of Contents……………………………………………………………….
ii
INTRODUCTION…………………………………………………….……….. 1
REVIEW OF LITERATURE…………………………………………………..
3
Importance of Growing
Watercress……………………………………………………………..
3
Conventional Agriculture………...……………………………………
3
Organic Agriculture…………………………………………………....
4
Environmental Benefits
5
of Organic Agriculture………………………………………………....
Benefits of Adding Organic
6
Matter to the Soil……………………………………………………....
Vermicompost……………………………………………….……….... 7
Liquid Organic Fertilizer…………………………………….………...
8
Organic Products ………………………………………………………
8
MATERIALS AND METHOD ........................................................................
9
RESULTS AND DISCUSSION………..…………………………………….
14
Yield per Plot………………………………………………………….
14
Dry Matter Yield………………………………………………………
14
Pests Infestation……………………………………………………….
15
Disease Incidence……………………………………………………...
17
Chemical Properties of the Soil……………………………………….
18
Economic Importance………………………………………………….
23
SUMMARY CONCLUSION AND
24
RECOMMENDATION………………………………………………………..
LITERATURE CITED…………………………………………………………
26
APPENDICES………………………………………………………………… 29
MARCELO, PRECIL D. APRIL 2012. Effects of the Different Application Rates of
Vermicompost on the Performance of Watercress ((Nasturtium officinale Lin.).Benguet State
University, La Trinidad, Benguet.
Adviser: Jose G. Balaoing, PhD
ABSTRACT
The effects of the different application rates of vermicompost on the performance of
watercress was conducted at the BSU Organic demo farm, Benguet State University, La
Trinidad, Benguet from November 2011 to February 2012. Specifically, the study aimed to
evaluate the effects of different rates of vermicompost on the yield performance and return on
cash expense of growing watercress and to evaluate the effect of the application of vermicompost
fertilizer on some chemical properties (pH, OM and N-contents) of the soil.
The yield of watercress was not influenced by the different application rates of
vermicompost. The dry matter yield of watercress on the other hand was affected by the
application rates of vermicompost.
Increasing rates of application from 5 to 20 t ha-1 of vermicompost affected the soil
chemical properties. Application of 20 t ha-1vermicompost gave the highest mean for soil pH,
%OM and Total N.
Application of 20, 15 and 5 t ha-1vermicompost gave high returns on cash expense by
105.32%, 92.91% and 91.29%, respectively.
Effects of the Different Application Rates of Vermicompost on the Performance of Watercres((Nasturtium
officinale Lin.)/ Precil D. Marcelo. 2012
1
INTRODUCTION
Watercress (Nasturtiumofficinale Lin.) is an aquatic plant that thrives with its
roots in water and its leaves in the sun. It is an aquatic, hardy perennial with succulent,
hollow branching stems. The creeping or floating stems root easily and bear fleshy, shiny,
heart-shaped leaves. The leaves are very dark green or bronze, with a distinctive peppery
taste. It is also tolerant to frost (Fennell, 2006).
Watercress belongs to brassicaceae family. It is known to the Philippines as
“Lampaken” and in Benguet, as “tongsoy”. It originated from western Asia but is
cultivated in Europe, United States and some parts of Asia. When traced back from the
ancient times, watercress were used by the Greeks, Romans and Persians for medical
purposes, as treatment for insanity (with vinegar), as a stimulant, and as a breath
freshener.
It is high in potassium, Vitamins A, C, and E, iron, folic acid, and calcium. It also
contains vitamin B6, which helps get blood glucose into normal level and even manganese
which is also helpful for women with osteoporosis problems.
The increase of productivity has always been the primary concern in every
agricultural and rural development efforts. Various methods and technology systems has
been employed and looked into as possible solutions to ensure high yields. However,
these methods are not always the best solutions. Most of them come at a certain price.
Certain techniques employed in ensuring high yields require high agricultural inputs such
as fertilizers and pesticides. These imposed additional cost that burdens small farmers.
The use of chemical fertilizers and pesticides tend to strip the soil of its natural nutrients,
thereby causing environment to degrade (Lim, 2002).
Effects of the Different Application Rates of Vermicompost on the Performance of
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2
Due to its economic and health importance, watercress production must be
encouraged for small farmers for additional income. This must be done through the
organic way of farming.
This study then serves as a guide for organic growers in the use of appropriate and
effective organic fertilizers as well as the proper management techniques in the
production of watercress without degrading the environment while sustaining agricultural
production.
The study focused on the effects of different application rates of vermicompost on
the performance of watercress (Nasturtium officinale Lin).
Specifically, the study was conducted to 1) evaluate the effects of different rates
of vermicompost on the yield performance and return on cash expense of growing
watercress and 2) evaluate the effect of the application of vermicompost fertilizer on
some chemical properties (pH, OM and N-contents) of the soil.
The study was conducted at the Organic Demo Farm experimental area,
Department of Soil Science, College of Agriculture, Benguet State University La
Trinidad Benguet from November 2011 to February 2012.
Effects of the Different Application Rates of Vermicompost on the Performance of
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3
REVIEW OF LITERATURE
Importance of Growing Watercress
Orwell (2011) said that watercress contains gluconasturin, a unique type of
phytochemical that is converted into PEITC (2- phenyl ethyl isothiocyanate), a volatile
compound sensitive to heat and moisture and is found to inhibit the growth of a number
of different kinds of cancer including breast cancer, colon, and prostate cancers.
In addition, the BBC website as cited by Bramwell (2010) reported that a study
published in American Journal of Clinical Nutrition found that eating watercress reduces
DNA damage in white blood cells.
Conventional Agriculture
Eicher(2003) defined Conventional agricultureasan industrialized agricultural
system characterized by mechanization, monocultures, and the use of synthetic inputs
such as chemical fertilizers and pesticides, with an emphasis on maximizing productivity
and profitability.
In these modern times, agriculture is becoming more and more dependent upon
the steady supply of artificial fertilizers and pesticides with the introduction of green
revolution techniques (Singh, 2009). However, these conventional farming which our
farmers had adopted brought lots of negative effects to the different aspects of human
life. Panganiban (2006) as cited by Macaroy (2007) also said that over the last years, the
reckless use of resources and the dependence on chemical based pesticides and fertilizers
had harmful and possibly permanent effects on the environment.
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The persistent use of chemical fertilizers causes the pollution of ground water
sources, or leaching. They are highly soluble being absorbed by the ground more rapidly
than the intended plants. Plants have the capacity to absorb only a given level of nutrition
at a time leaving the rest of the fertilizer to leach. Leaching is not only hazardous to
groundwater sources but also to the health of subsoil where these chemicals react with
clay to create hard layers of soil known as hardpan (Sarfaras, 2011).
The synthetic chemicals in the chemical fertilizers adversely affect the health of
naturally found soil micro-organisms by affecting the soil pH. These altered levels of
acidity in the soil eliminate the micro-organisms beneficial to plant and soil health as they
help to increase the plants' natural defenses against pests and diseases. The use of
chemical fertilizers affects the health of bacteria that fix the nitrogen balance in the soil
(Sarfaras, 2011).
Given this picture, going back to Organic Agriculture which had long been
practiced in the olden times should be the priority of today’s agriculture. The use of
sustainable practices which ensures high productivity and profitability without degrading
the environment must be taken into consideration.
Organic Agriculture
Organic Agriculture is a type of farming system that promotes the use of
renewable resources and management of biological cycles to enhance biological diversity
without the use of genetically modified organisms or synthetic pesticides, herbicides and
fertilizers for the production of plants as well as the refrain from using synthetic food
stuffs, growth hormones and antibiotics for the production of animals (Eicher, 2003).
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5
It is also defined by the USA’s National Organic Standards Board (1996) as cited
by Balaoing (2010) as an ecological production management system that promotes and
enhances biodiversity, biological cycles and soil biological activities.
IFOAM(2005) as cited by Asian Development Bank Institute (2011) defines
organic agriculture as a “holistic production management system which promotes and
enhances agro-ecosystem health, including biodiversity, biological cycles, and soil
biological activity. It emphasizes the use of management practices in preference to the
use of off-farm inputs, taking into account that regional conditions require locally
adapted systems.”
Organic production relies on management techniques that maintain and replenish
the long term soil fertility by optimizing the soil’s biological activity. These are achieved
through crop rotation, cover cropping, use of compost and any organically accepted
fertilizers that feed the soil while providing the plants with nutrients (Guerena, 2006).
Environmental Benefits of Organic Agriculture
Organic farming protects our water supply in a way that it bans artificial
fertilizers to pollute water supply, it preserves healthy soils, prevents biodiversity loss,
supports sustainable practices, saves energy and less fossil fuels, it also nurtures and
protects wildlife and lastly, it helps maintain our rural communities in a way that organic
farmers are independent and small in size that represents one of the few readily available
and viable strategies for the survival of rural communities (Balaoing, 2010).
Food and Agriculture Organization (2011) also said that organic agriculture
benefits the soil by encouraging soil fauna and flora thus improving soil formation and
structure and creating more stable systems. In turn, nutrient and energy cycling is
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6
increased and the retentive abilities of the soil for nutrients and water are enhanced,
compensating for the non-use of mineral fertilizers. Greater biodiversity which is
employed in organic agriculture enhances soil structure and water infiltration. Properly
managed organic systems with better nutrient retentive abilities greatly reduce the risk of
groundwater pollution.
Organic agriculture as well reduces non-renewable energy use by decreasing
agrochemical needs. It contributes to mitigating the greenhouse effect and global
warming through its ability to sequester carbon in the soil. Many management practices
used by organic agriculture increase the return of carbon to the soil, raising productivity
and favoring carbon storage. The impact of organic agriculture on natural resources
favors interactions within the agro-ecosystem that is vital for both agricultural production
and nature conservation. Ecological services derived include soil forming and
conditioning, soil stabilization, waste recycling, carbon sequestration, nutrients cycling,
predation, pollination and habitats. By opting for organic products, the consumer through
his/her purchasing power promotes a less polluting agricultural system. The hidden costs
of agriculture to the environment in terms of natural resource degradation are reduced.
Benefits of Adding Organic Matter to the Soil
Organic matter is a reservoir of nutrients that can be released to the soil. Each
percent of organic matter in the soil releases 20-30 pounds of N, 4.5-6.6 pounds of P2 O5
and 2-3 pounds of sulfur per year. Organic matter also absorbs and holds up to 90% of its
weight in water which is released for plant absorption. It causes soil to clump and form
aggregates which improves soil structure. With better soil structure, permeability
Effects of the Different Application Rates of Vermicompost on the Performance of
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7
improves in turn, improving the soils ability to take up and hold water. Lastly, organic
matter prevents erosion (Funderburg, 2011).
MacRae and Mehuys (1990) added that organic matter plays more of a role in
aggregate stability than in aggregate formation. It is, in fact, the primary stabilizing agent
for aggregates in temperate-area soils. This stabilization process is accomplished mainly
through the by-products of organic matter decomposition (microbial gums and
mucilages). Organic matter also decreases the bulk density of soil.
The humus added to soil by organic fertilizers helps stabilize soil aggregates,
improving tilth. It helps separate the particles in clay soil, which makes the soil looser
and easier to work as well as easier for roots to penetrate. In sandy soil, humus acts as a
binder to hold particles together so they don't wash away from the plants' roots, and it
improves moisture retention. Humus and compost condition the soil, adds nutrients and
improves the water retention properties. Healthy, organic soil has sponge-like properties
that enhance the movement of water through the soil. Increased soil moisture aids
microbes as they convert nutrients into a form plants can use, and it keeps those nutrients
suspended so they are readily available for uptake by plants' root systems. Organic
fertilizers supply natural sources of nutrients that microbes can process easily (Fischer,
2010).
Vermi Compost
Sundaram Overseas Operation (2008) said that vermi compost enriches the soil in
most natural organic manner and also increases the quality, fertility and mineral content
of the soil. As compared to chemical fertilizers, organic fertilizer is completely harmless
and provides rich organic soil that is best for plants while chemical fertilizers destroy
Effects of the Different Application Rates of Vermicompost on the Performance of
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8
beneficial microorganisms. In addition, vermi compost contains more than eight kinds of
useful microbial bacterium groups (over 600 million per gram) wherein it can supply all
nutrition elements needed by variety of plants.
Liquid Organic Fertilizer
Zulueta (1982) as cited by Tomin (2011) said that Liquid organic fertilizers play
an important role in plant growth particularly leafy vegetable crops. It gives a very
important source of mineral elements and food for the plant. It has been extensively used
in irrigated lands for direct application to crops.
Organic Products
Organic crops differ in nutrient content from conventional crops. Organic crops
contained significantly more vitamin C, iron, magnesium, and phosphorous and
significantly less nitrates. These were significant trends showing less protein but of a
better quality and higher content of nutritionally significant minerals with lower amounts
of some heavy metals in organic crops compared to conventional ones (Worthington,
2001).
Effects of the Different Application Rates of Vermicompost on the Performance of
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9
MATERIALS AND METHODS
The materials used in the research experiment were stem cuttings of watercress of
similar length (3 inches) and maturity, vermicompost which was obtained from the BSU
Organic Demo Farm, liquid organic fertilizer derived from 13 kg chopped banana trunk;
13 kg chopped wild sun flower and 1 L molasses fermented for 7-10 days, identifying
tags which was used for treatment identification and farm implements such as sickle,
cultivator, and hoes.
A total land area of 50 m2 was thoroughly prepared following watercress culture
production. Puddling the soil for the purpose of water conservation and maintenance is
necessary to grow watercress in the area. The area was divided into four (4) blocks with
each block having five (5) treatment plots measuring 1mx2m each. Border plot of at least
1 foot width was used to separate each treatment to avoid contamination. Each treatment
was planted with 2 kg of watercress stem cuttings after the application of vermicompost
following the different rates studied.
Application of the different amounts of vermicompost were done by thoroughly
incorporating this a week before planting.
Blanket application of liquid organic fertilizer of about 500 ml diluted LOF
derived from fermented 13 kg chopped banana trunk, 13 kg chopped wild sunflower and
1 L molasses was applied 1 week after planting at an interval of 7 days.
Effects of the Different Application Rates of Vermicompost on the Performance of
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10
Figure 1. Field layout of the experimental area located at the BSU
organic demo farm, La Trinidad, Benguet
Figure 2. Fermented chopped sunflower, banana trunk and molasses as
liquid organic fertilizer
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11
The following treatments studied were as follows:
C1 = No fertilizer input + Liquid Organic Fertilizer
C2 = 5 tons/ha vermicompost + Liquid Organic Fertilizer
C3 = 10 tons/ha vermicompost + Liquid Organic Fertilizer
C4 = 15 tons/ha vermicompost + Liquid Organic Fertilizer
C5 = 20 tons/ha vermicompost + Liquid Organic Fertilizer
The different treatments were laid out in the experimental area following the
Randomized Complete Block Design (RCBD) with four (4) replications.
The data gathered were:
1. Fresh weight of water cress at harvest
Staggered harvesting of watercress was done throughout the conduct of the study.
This was marketed into one-fourth (1/4) kg or 250 g labeled as organic product at the
BSU Organic Market.
2. Dry matter yield
This was gathered by weighing twenty grams of watercress separately for each
treatment and was cut into pieces. It was oven dried for 24 hours. This was recorded and
computed using the following formula:
Dry matter = 100% - % Moisture Content
Where: % Moisture Content = FW – ODW x 100
ODW
3. Insect Pest Incidence
The plants were observed and the occurrence of insect pests was noted. The
insects that attacked the watercress and the damage they caused was monitored and
Effects of the Different Application Rates of Vermicompost on the Performance of
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12
recorded. The arbitrary rating scale used by Halog and Molina (1981) is shown
below.
Scale
Description
1
Sound, leaves with no damage
2
Slight, 1-3 leaves affected
3
Moderate, 4-6 leaves affected
4
Severe, most of the leaves affected
5
Skeletonized, all leaves affected
4. Disease Incidence
The plants were observed and the occurrence of diseases was recorded. Diseases
were rated using the arbitrary rating scale used by Lasilas, (2010) asshown below.
Scale
Description
1
No infection
2
1-25% of the total plant
3
26-50% of the total plant
4
51-71% of the total plant
5
76-100% of the total plant
5. Soil Analysis- Soil samples were collected before planting and after harvest for the
following analysis using PCCARD standard method:
a. Soil pH. This was determined using 1:2.5 CaCl2 soil suspension. A 10 g of air
dried soil was weighed into a 100 ml beaker. Then 25 ml of 0.01 M CaCl2 was added and
Effects of the Different Application Rates of Vermicompost on the Performance of
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13
stirred thoroughly and periodically for 15 to 20 minutes. The pH meter was calibrated
with the standard buffer solution. The electrode of pH meter reading was recorded.
b. Organic matter content of the soil (%). One gram of oven dried soil was placed
in a 250 ml conical flask. Then 10 ml of 1N K2 Cr2 O7 was added followed by an
immediate and rapid addition of concentrated H2SO4. The soil solution was mixed gently
and it was allowed to be digested in the fume hood. After digestion, 250 ml of distilled
water was added. Concentrated H3BO3 and 1.0 ml of diphenylamine indicator solution
was added to the filtrate. The solution was titrated with standard 0.5 N FeSO4. Titration
was stopped when the initial color of yellowish brown changed from blue to violet to
green abruptly. The green color indicated the end point. A blank sample was prepared
following the same procedure except that no soil will be added. The % Organic matter
was computed using the formula:
% OM = 10(S-T) x 0.0069 x 100
S wt. of soil sample
Where S = ml of ferrous solution required for blank
T = ml of ferrous solution required for sample
c. Nitrogen Content of the Soil (%). The Nitrogen content of the soil was
computed by multiplying the OM content by 0.05.
6. Return on Cash Expenses
This was done by recording all the expenses and production rates. It was
computed using the formula;
ROCE (%) = Gross income – Total Expensesx 100%
Total Expenses
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14
RESULTS AND DISCUSSION
Yield of Parameters of Watercess as Affected by
the Different Application Rates
ofVermicompost
Yield per Plot
Table 1 shows the watercress yield per plot as affected by the different rates of
vermicompost. There were no significant differences obtained in the analysis. However,
plant grown from those applied with 20 t ha-1vermicompost had the highest yield of 4.14
kg per plot. Untreated plots registered the lowest yield of 3.033 kg per plot. This implies
that application of vermicompost enhances yield of watercress.
Dry Matter Yield
The dry mater yield of watercress as affected by the different application rates of
vermicompost is shown in Table 2. Plants grown from those applied with 20 t ha-1, 15
Table 1. Yield per plot as affected by the different application rates of vermicompost.
TREATMENT
MEAN
C1
=
Control
3.033a
C2
=
5tons/ha
VC
+
LOF
3.405a
C3
=
10tons/ha
VC
+
LOF
3.155a
C4
=
15tons/ha
VC
+
LOF
3.743a
C5
=
20
tons/ha
VC
+
LOF
4.148a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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15
t ha-1 and 10 t ha-1vermicompost had the highest mean of 8.55 g, 7.225g, and 7.705 g
respectively. Plants grown from those untreated plots gave the lowest mean of 4.725 g.
The result implies that application of vermicompost enhances the dry matter yield of
watercress. This confirms the study of Azarmiet. al. (2008) wherein application of
vermicompost at the rate of 15 t ha-1 increases the dry matter yield of tomato fruit by
24%.
Pest Infestations as Affected by the
Different Application Rates
ofVermicompost
Snail Infestation
Table 3 shows the ratings of snail infestations of watercress as affected by the
different application rates of vermicompost. Plants treated with 10 t ha-1vermicompost
Table 2.Dry matter yield of watercress as affected by the different application rates of
vermicompost.
TREATMENT
MEAN
C1
=
Control
4.725bc
C2
=
5tons/ha
VC
+
LOF
6.625b
C3
=
10tons/ha
VC
+
LOF
7.705a
C4
=
15tons/ha
VC
+
LOF
7.225a
C5
=
20
tons/ha
VC
+
LOF
8.550a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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16
significantly had the highest rate of 3.75 snail infestation. Lowest rate of snail infestation
was noted from those plants applied with 5 t ha-1vermicompost.
Flee Beetle Infestation
Flee Beetle infestation as shown in Table 3 showed that highest rate of 2.25
(Slight damage) snail infestation was observed from untreated plots while lowest rate of
1.125 (no damage) was noted from plants applied with 20 t ha-1vermicompost.
Cabbage Worm
Cabbage worm infestation (Figure 3) showed no significant differences (Table 3).
However, highest rate of infestation which is 1.186 (no damage) was observed from
plants treated with 5 t ha-1vermicompost and the lowest rate which is 1 (no damage) was
noted from both plants applied with 15 t ha-1 and 20 t ha-1vermicompost.
Table 3.Pest infestations of watercress as influenced by the different application rates of
vermicompost.
TREATMENT
______RATE OF PEST DAMAGE______
SNAIL FLEEBEETLE CABBAGE
WORM
C1
=
Control
1.50bc
2.25a
1.125a
C2 = 5tons/ha VC + LOF
1.25b
1.375a
1.186a
C3 = 10tons/ha VC + LOF
3.75a
1.438a
1.125a
C4 = 15tons/ha VC + LOF
1.75b
1.375a
1.000a
C5 = 20 tons/ha VC + LOF
2.00b
1.125a
1.000a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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17
Disease Incidence of Watercress as Affected
by the Different Application Rates
ofVermicompost
Aster Yellow Infection
Statistics revealed no significant differences in the infestation of aster yellow
disease of watercress (Figure 3) as influenced by the different application rates
ofvermicompost (Table 4). However, highest rate of infestation were observed from
untreated plants, plants applied with 5 t ha-1, and 15tons ha-1vermicompost having a mean
of 1.75%. Lowest rate of 1.25% was noted from plants applied with 20 t ha-
1vermicompost. Aster yellow is one among the serious diseases of watercress production
(McHugh, 2012).
Table 4. Aster yellow disease of watercress as affected by the different application rates
of
vermicompost.
TREATMENT
MEAN
C1
=
Control
1.75a
C2
=
5tons/ha
VC
+
LOF
1.75a
C3
=
10tons/ha
VC
+
LOF
1.50a
C4
=
15tons/ha
VC
+
LOF
1.75a
C5
=
20
tons/ha
VC
+
LOF
1.25a
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT.
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Figure 3. Aster yellow disease and cabbage worm infestation
Some Chemical Properties of the Soil
Initial Properties of the Soil
The initial properties of the soil were analyzed before planting (Table 5). The
initial pH of the soil was 5.7 indicating that the soil is slightly acidic. The nitrogen
content and organic matter content were 0.12% and 2.56% respectively. The initial pH of
the soil is low in terms of the favorable soil pH for watercress production which is neutral
or 7.0 (McHugh, 2012). Organic matter content on the other hand is slight low and it did
not reach the range for mineral surface soils which is 3-5% by weight (Brady, 1985). This
implies that application of organic fertilizer is necessary to supplement the soil.
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Table 5.Initial Soil Properties.
PROPERTY
CONTENT
A. Chemical Properties
1. pH
5.7
2. N
(%)
0.12
3. OM
(%)
2.56
Final Soil pH
Table 6 shows the final pH of the soil as affected by the different application rates
of vermicompost. An increase on the soil pH was noted from vermicompost application
from the initial soil pH of 5.7. Plots applied with 5, 10, 15 and 20 t ha-
1vermicompostgave corresponding increases of 17.37%, 17.54%, 21.58%, and 26.00%
respectively overthe initial pH value of 5.70. Likewise, an increase of 14.04% was
observed from plots without vermicompost application. The observation can be attributed
to the ability of the organic material to buffer changes in soil pH.
Organic Matter Content of the Soil
Organic matter content of the soil was influenced by the application rates of
vermicompost (Table 7). There were observed increase of the organic matter contents of
the soil where vermicompost was applied from 5 to 20 t ha-1 over the initial value of
2.56%.
Moreover, statistical analysis showed highly significant differences among the
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20
treatments. Plots applied with 20, 15, 10, and 5 t ha-1vermicompost differ at about
98.47%, 97.55%, 89.26%, and 53.68% respectively over the control. An increase in
theOM content in the control plots as compared to the initial (2.56%) could be attributed
to the blanket application of Liquid organic fertilizer. Results implied that increasing the
rate of application for vermicompost increases the organic matter content of the soil.
Arancon and Edwards (2005) said that the application of vermicompost in the field
enhances the quality of soils by increasing microbial activity and microbial biomass
which are key components in nutrient cycling, production of plant growth regulators and
protecting plants soil-borne disease and arthropod pest attacks.
Table 6. Soil pH as affected by the different application rates of vermicompost.
TREATMENT
MEAN
C1
=
Control
6.50e
C2
=
5tons/ha
VC
+
LOF
6.70d
C3
=
10tons/ha
VC
+
LOF
6.70c
C4
=
15tons/ha
VC
+
LOF
6.93b
C5
=
20
tons/ha
VC
+
LOF
7.00a
Initial
5.70
Means followed by a common letter /s in a column are not significantly different at 0.05
level by DMRT.
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Table 7.Organic matter content of the soil as affected by the different application rates of
vermicompost.
TREATMENT
MEAN
C1
=
Control
3.26c
C2
=
5tons/ha
VC
+
LOF
5.01c
C3
=
10tons/ha
VC
+
LOF
6.17b
C4
=
15tons/ha
VC
+
LOF
6.44a
C5
=
20
tons/ha
VC
+
LOF
6.47a
Initial
2.56
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT
Total Nitrogen Content of the Soil
Total nitrogen of the soil was influenced by the application of different rates of
vermicompost (Table 8). Application of increasing rates of vermicompost affected
thetotal nitrogen content of the soil as compared to the initial which is 0.12%. An
increase of 33.33%, 116.67%, 158.33%, 166.67% and 191.67% was observed from plots
treated with 5, 10, 15 and 20 t ha-1vermicompost respectively.
Likewise, application of 20, 15, 10, and 5 t ha-1vermicompost differ at about
118.75%, 100%, 93.75% and 62.50% respectively over the control.
An increase in the total nitrogen in the untreated plants having 0.16% as
compared to the initial (0.12%) could be attributed to the blanket application of liquid
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
22
Table 8.Total Nitrogen content of the soil as affected by the different application rates of
vermicompost.
TREATMENT
MEAN
C1
=
Control
0.16c
C2
=
5tons/ha
VC
+
LOF
0.26c
C3
=
10tons/ha
VC
+
LOF
0.31b
C4
=
15tons/ha
VC
+
LOF
0.32a
C5
=
20
tons/ha
VC
+
LOF
0.35a
Initial
0.12
Means followed by a common letter / s in a column are not significantly different at 0.05
level by DMRT
organic fertilizer. This implies that increasing rates of vermicompost increases total
nitrogen of the soil.
Economic Importance
Return on Cash Expenses
The return on cash expenses of watercress as affected by the different application
rates of vermicompost is shown in Table 9. Plants applied with 20 tha-1vermicompost
gave the highest ROCE of 105.32%. This implies that for every 1 peso investment, there
is a 105.32 return of investment. Plots applied with 15 and 5 tha-1vermicompost on the
other hand have a peso investment return of 92.91 and 91.29 respectively. Lowest ROCE
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
23
was noted from untreated plants and plants applied with 10 tha-1vermicompost having
78.38% and 69.62% respectively.
Plots applied with 10 t ha-1 which has the lowest ROCE was attributed to the
attack of snails which had caused major damage to the plants as shown in Table 7.
Table 9. Cost and return analysis of watercress applied with the different application
rates of vermicompost.
TREATMENT Yield
/2m2 GROSS
COST
OF NET
%ROCE
(kg)
INCOME
PRODUC-
INCOME
(Php)
TION
(
Php)__(Php)
_____________
C1
12.13
1,213
680
533
78.38
C2
13.62
1,362
712
650
91.29
C3
12.62
1,262
744
518
69.62
C4
14.97
1,497
776
721
92.91
C5
16.59
1,659
808
851
105.32
Price was computed at Php100/kg.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
24
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
The study was conducted at the BSUOrganic Demo Farm, Benguet State
University, La Trinidad, Benguetfrom November 2011 to February 2012.The study was
conducted to: 1) to evaluate the effects of different rates of vermicompost on the yield
performance and return on cash expense of growing watercress and 2) to evaluate the
effect of the application of vermicompost fertilizer on some chemical properties (pH, OM
and N-contents) of the soil.
The different application rates of vermicompost did not influence the total yield of
watercress. However, the dry matter yield of watercress was affected by the application
of vermicompost.
The initial soil pH was increased with the increasing rates of vermicompost to a
favorable pH for watercress production. Percent OM and total N content of the soil
however, is at the optimum level and it is most likely sufficient for plant growth.
Application of vermicompost tend to increase these soil chemical properties because
plants treated with the highest rate of vermicompost gave the highest value for soil pH
and both % OM and % N.
The return on cash expense (ROCE) showed that high returns were obtained from
plants grown in plots applied with 20, 15 and 5 tons ha-1vermicompost having 105.52%,
92.91% and93.29%respectively.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
25
Conclusion
Based on the results of the experiment, the following conclusions were drawn:
1. Increased application rates of vermicompost influenced the chemical properties
of soil studied thus is effective in increasing the yield of watercress. However, the yield
increase based on the different application rates of vermicompost was not significant.
2. Vermicompostapplication of 5, 15 and 20 t ha-1 gave high economic benefits
compared to the control.
Recommendation
Application of either 20 tha-1 or 15 tha-1vermicompost is recommended as best
application rates for growing watercress. Further study however, is recommended to
verify the results.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
26
LITERATURE CITED
ARANCON, N.Q. and EDWARDS, C.A. 2010. Effects of vermicomposts on plant
growth. Retrieved March 18, 2012 from http://www.slocountyworms.com/wp-
content/uploads/2010/12/effects-of-vermicomposts-on-plant- growth.pdf
ASIAN DEVELOPMENT BANK IINSTITUTE. 2011. Organic agriculture and
certification: an over view. Retrieved October 3,
2011, from http://www.adbi.
org/discussion-paper/2008/08/25/2675.organic.fairtrade.certification/organic.
agriculture.and.certification.an.overview/
AZARMI, R. PARVIS, S.V. and MOHAMMAD, R.S. 2008. Effect of vermicompost on
growth, yield and nutrition status of tomato (Lycopersicumesculentum).
Retrieved March 18,2012 fromhttp://scialert.net/fulltext/?doi=pjbs.2008.1797.
1802
BALAOING, J.G. 2010.Technologies in organic agriculture. Lecture Presented in
Bontoc,
Mt.
Province
BRADY, N.C. 1985. The nature and properties of soils.McMilan Publishing Company,
Pp. 15 and 50.
BRAMWELL, A. 2010.Watercress growing requirements. Retrieved June 6, 2011, from
http://www.ehow.com/list_7553806_growing-
requirements.html:
EICHER, A. 2003.A glossary of terms for farmers & gardeners. Retrieved June 10,
2011,
from
http://ucce.ucdavis.edu/files/filelibrary/1068/8286.pdf
FOOD AND AGRICULTURE ORGANIZATION. 2011. What are the environmental
benefits of organic agriculture?
Retrieved
September 29, 2011, from
http://www.fao.org/organicag/oa-faq/oa-faq6/en/
FENNELL, J.F. 2006.Potential for watercress production in Australia.Retrieved June
6, 2011, from http://www.rirdc.infoservices.com.au/downloads/06-105.pdf
FISCHER, F. 2010. The effects of organic fertilizer. Retrieved October 04, 2011, from
http://www.livestrong.com/article/256216-the-effects-of-organic- fertilizer/
FUNDERBURG, E. 2011. What does organic matter do in soil? The Samuel
Roberts noble foundation. Retrieved June 6, 2011, from
http://www.noble.org/Ag/Soils/organic matter/index.htm
GUERENA, M. 2006. Cole crops and other Brassicas: AT TRA Organic production.
Retrieved June 6, 2011, from http://74.6.117.48/search/srpache?ei=UTF-
8&p=organic+production+of+watercress&rd=r1&meta
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
27
HALOG, J.M. and L.R. MOLINA. 1981. Field and greenhouse study on the biological
control of diamond backmoth of cabbage using bactospeine and dipel. BS Thesis.
Benguet State University, La Trinidad Benguet.P.26.
LASILAS, N.L. 2010. Status of virus infection in Potato variety Igorota and its
implication to the informal seed system. BS Thesis. Benguet State University, La
Trinidad
Benguet.P.16.
LIM, A. K. 2002. Natural farming technology seminar. Lecture presented in
La
Trinidad,
Benguet.
MACAROY, J. 2007. Production and marketing practices of the members of the La
Trinidad Organic Practitioners in La Trinidad Benguet. BS Thesis. Benguet State
University. La Trinidad Benguet.P. 4.
MACRAE, R.J. and G.R. MEHUYS. 1990. The effect of green manuring on the physical
properties of temperate-area soils. Retrieved October 04, 2011, from
http://www.sarep.ucdavis.edu/NEWSLTR/v2n4/sa-5.htm
McHUGH, J.J. 2012.Crop profile for watercress in Hawaii. Retrieved March 12, 2012,
from http://www.ipmcentres.org/cropprofiles/docs/HIwatercress.pdf
McHUGH, J.J. and CONSTANTINIDES, L.N. 2004.Pest management strategic plan for
watercress production in Hawaii. Retrieved March 14, 2012, from
http://www.ipmcenters.org/pmsp/pdf/HIwatercress.pdf
ORWELL, M. 2011. Health benefits of watercress. Retrieved June 6, 2011, from
http://www.Ehow.com/facts_4780289_health-benefits-watercress.htm
SARFARAS, I. 2011. The effects of chemical fertilizers on soil. Retrieved October 04,
2011 from http://www.ehow.com/list_6603980_effects-chemical-fertilizers-
soil.html#ixzz1ZnW6FCqZ
SUNDARAM OVERSEAS OPERATION. 2008. Vermi compost fertilizer. Retrieved
March 25, 2011, from http://www.soo.coin/fertilizer.htm
SINGH, A. 2009.Hazardous effects of chemical fertilizers and pesticides. Retrieved
June 10, 2011, from http://andamanchronicle.com/content/view/1627/62/
TOMIN, G. 2011. Rates of vermi compost and frequency of sunflower extract
application on some soil properties and performance of French beans
(Phaseolus vulgaris L.)BS Thesis. Benguet State University, La Trinidad
Benguet.P.
9.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
28
WORTHINGTON, V. 2001.Nutritional quality of organic vs. conventional fruits,
vegetables and grains. The Journal of all alternative and complementary
medicine . Retrieved June
10, 2011, from
http://www.chiro.org/
nutrition/FULL/Nutritional_quality_oforganic _versus_convebtional
_fruits_htm
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
29
APPENDICES
Appendix Table 1. Yield per plot (kg/2m2)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
1.45 4.28 3.51 2.89 12.13
3.033
C2
4.37 3.63 2.13 3.49 13.62
3.405
C3
3.28 2.36 2.80 4.18 12.62
3.155
C4
3.34 4.62 3.45 3.56 14.97
3.743
C5
3.72 5.01 4.35 3.51 16.59
4.148
TOTAL
16.16 19.9 16.24
17.63 69.93 17.484
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
1.83
0.61
TREATMENT 4
3.30 0.825
1.06ns
3.26 5.41
ERROR
12
9.34 0.778
TOTAL 19
14.47
2.21
ns
-
Not
Significant
%CV=
5.04
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
30
Appendix Table 2. Dry matter yield (g)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
4.4
4.5 4.9
5.1
18.9
4.725
C2
6.3
8.4 6.0
5.8
26.9
6.625
C3
8.7
5.7 7.2
6.6
28.2
7.050
C4
5.7
8.1 8.0
7.1
28.9
7.225
C5
9.1
8.3 8.6
8.2
34.2
8.550
TOTAL
34.2 35 34.7 32.8 137.1
34.175
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.574
0.191
TREATMENT 4
30.55 7.638
7.03** 3.26 5.41
ERROR
12
13.05 1.087
TOTAL
19
44.17
8.916
**-
Highly
Significant
%CV=
3.05
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
31
Appendix Table 3. Snail’s infestation on watercress
TREATMENT
BLOCK
TOTAL MEAN
I
II III
IV
C1
1
2
2
1 6
1.50
C2
1
1
2
1 5
1.25
C3
2
5
4
3
15
3.75
C4
1
3
1
2
7
1.75
C5
2
2
1
3
8
2.00
TOTAL
8 13 10
10 41 10.25
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
2.55
0.85
TREATMENT 4
15.7 3.93
7.02**
3.26 5.41
ERROR
12
6.7 0.56
TOTAL
19
44.17
5.34
**-
Highly
Significant %CV=
7.30
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
32
Appendix Table 4. Flee Beetle infestation on watercress
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
2.00 1.75 2.00
1.00
6.75
2.250
C2
1.75 1.00 1.25
1.50
5.50
1.375
C3
1.00 2.00 1.75
1.00
5.75
1.438
C4
1.75 1.00 1.00
1.75
5.50
1.375
C5
1.00 1.50 1.00
1.00
4.50
1.125
TOTAL
7.50 7.25 7.00 6.25 28.00 7.563
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.175
0.058
TREATMENT 4
0.644 0.161
0.82ns
3.26 5.41
ERROR
12
2.356 0.196
TOTAL
19
44.17
0.415
ns
-
Not
Significant
%CV=
5.85
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
33
Appendix Table 5. Cabbage worm infestation on watercress
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
1
1
1 1.5
4.5
1.125
C2
1
1
1 1.75
4.75
1.186
C3
1
1
1 1.5
4.5
1.125
C4
1
1
1 1
4
1.00
C5
1
1
1 1
4
1.00
TOTAL
5
5
5 6.75 21.75 5.436
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.463
0.154
TREATMENT 4
0.116 0.029
1.04ns 3.26 5.41
ERROR
12
0.3340.028
TOTAL
19
0.913
0.211
ns
-
Not
Significant
%CV=
3.08
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
34
Appendix Table 6. Aster yellow disease infestation on watercress (%)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
1
2
1
3
7
1.75
C2
1
2
2
2
7
1.75
C3
1
1
1
3
6
1.50
C4
1
2
1
3
7
1.75
C5
1
1
2
1
5
1.25
TOTAL
5
8
7
12
32
8
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
5.2
1.73
TREATMENT 4
0.8
0.20
0.5ns
3.26 5.41
ERROR
12
4.8 0.40
TOTAL
19
44.17
2.30
ns
-
Not
Significant
%CV=
8.84
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
35
Appendix Table 7. Soil pH
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
6.55 6.43
6.54 6.46
25.98
6.495
C2
6.73 6.72 6.65 6.67
26.77
6.693
C3
6.73 6.67 6.71 6.70
26.81
6.703
C4
6.76 7.01 6.96 6.98
27.71
6.928
C5
6.93 7.00 7.08 6.97
27.98
6.995
TOTAL
33.7 33.83 33.94 33.78 135.25 33.813
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.0042 0.0014
TREATMENT 4
0.6435 0.1609
30.36**
3.26 5.41
ERROR
12
0.0634 0.0053
TOTAL
19
0.711
0.1676
**
Highly
Significant
%CV=
0.21
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
36
Appendix Table 8. Organic matter content of the soil (%)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
3.08 3.18
3.38 3.28
13.02
3.26
C2
4.47 5.86 5.26 4.96
20.05
5.01
C3
6.25 6.06 6.16 6.21
24.68
6.17
C4
6.50 6.40 6.42 6.43
25.75
6.44
C5
6.21 6.55 6.75 6.35
25.86
6.47
TOTAL
26.61 28.05 27.97 33.78 109.36 27.35
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.362
0.121
TREATMENT 4
30.72 7.532
73.126** 3.26 5.41
ERROR
12
1.241 0.103
TOTAL
19
32.323
7.756
**-
Highly
Significant %CV=
1.17
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
37
Appendix Table 9. Total nitrogen content of the soil (%)
TREATMENT BLOCK TOTAL MEAN
I
II III
IV
C1
0.16 0.16
0.17 0.16
0.65
0.16
C2
0.22 0.29 0.26 0.25
1.02
0.26
C3
0.31 0.30 0.31 0.31
1.23
0.31
C4
0.33 0.32 0.32 0.32
1.29
0.32
C5
0.31 0.33 0.38 0.32
1.34
0.35
TOTAL
1.33 1.40 1.44 1.36 5.53 1.40
ANALYSIS OF VARIANCE
SOURCE OF DEGREE SUM OF
MEAN OF COMPUTED TABULATED
VARIANCE OF
SQUARES SQUARES
F
F
FREEDOM
0.05 0.01
BLOCK
3
0.001 0.0003
TREATMENT 4
0.080 0.0200
50.00**
3.26 5.41
ERROR
12
0.005 0.0004
TOTAL
19
0.086
0.0207
**
-
Highly
Significant %CV=
1.43
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
38
Appendix Table 10. Return on cash expenses
TREATMENT Yield
/Plot
GROSS COST
OF
NET
%ROCE
(kg)
INCOME
PRODUC-
INCOME
(Php)
TION
(
Php)__(Php)
_____________
C1
12.13
1,213
680
533
78.38
C2
13.62
1,362
712
650
91.29
C3
12.62
1,262
744
518
69.62
C4
14.97
1,497
776
721
92.91
C5
16.59
1,659
808
851
105.32
Price used in the computation of gross income is Php 100.
Effects of the Different Application Rates of Vermicompost on the Performance of
Watercres((Nasturtium officinale Lin.)/ Precil D. Marcelo. 2012
TABLE OF CONTENTS
Page
Bibliography…………………………………………………………………….. i
Abstract…………………………………………………………………………
i
Table of Contents……………………………………………………………….
ii
INTRODUCTION…………………………………………………….……….. 1
REVIEW OF LITERATURE…………………………………………………..
3
Importance of Growing
Watercress……………………………………………………………..
3
Conventional Agriculture………...……………………………………
3
Organic Agriculture…………………………………………………....
4
Environmental Benefits
5
of Organic Agriculture………………………………………………....
Benefits of Adding Organic
6
Matter to the Soil……………………………………………………....
Vermicompost……………………………………………….……….... 7
Liquid Organic Fertilizer…………………………………….………...
8
Organic Products ………………………………………………………
8
MATERIALS AND METHOD ........................................................................
9
RESULTS AND DISCUSSION………..…………………………………….
14
Yield per Plot………………………………………………………….
14
Dry Matter Yield………………………………………………………
14
Pests Infestation……………………………………………………….
15
Disease Incidence……………………………………………………...
17
Chemical Properties of the Soil……………………………………….
18
Economic Importance………………………………………………….
23
SUMMARY CONCLUSION AND
24
RECOMMENDATION………………………………………………………..
LITERATURE CITED…………………………………………………………
26
APPENDICES………………………………………………………………… 29
Document Outline
- Effects of the Different Application Rates ofVermicompost on the Performance of Watercress ((Nasturtium officinale Lin.)
- BIBLIOGRAPHY
- TABLE OF CONTENTS
- INTRODUCTION
- REVIEW OF LITERATURE
- MATERIALS AND METHODS
- RESULTS AND DISCUSSION
- SUMMARY, CONCLUSION AND RECOMMENDATION
- LITERATURE CITED
- APPENDICES