1
Potency of Burned Soil as a Natural Fertilizer for
Cultivation of Pechay (Brassica Rapa)
Justin D. Obnamia
John Kenji L. Peñero
Jillian Mae T. Cosejo
Arnea Suzette M. Ytac
Academic Track
Science, Technology, Engineering, and Mathematics (STEM) Strand
Practical Research 2 / Inquiries, Investigation, and Immersion
Mrs. Shiela Niña L. Rea-Santes
March 31, 2023
Author Note
This paper was made in partial fulfillment of the requirements in Practical Research and
Inquiries, Investigation, and Immersion. Results were shared before the Faculty of the Senior
High School Department of Paaralang Sekundarya ng Lucban Integrated School (PSLIS). We
have no conflicts of interest to disclose.
Correspondence concerning this article should be addressed to Justin D. Obnamia,
Affiliation, 12 A. Regidor St. Brgy. 9, and obnamiajustin@gmail.com
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Chapter I
THE PROBLEM AND ITS SETTING
Introduction
The use of alternative fertilizers has become more popular in the quest for
environmentally friendly and sustainable agricultural practices. Burned soil, which is frequently
seen as a byproduct of conventional slash-and-burn agriculture, offers an intriguing possibility
as a natural fertilizer for pechay (Brassica Rapa) cultivation. This cruciferous vegetable
provides a distinctive testing environment for examining the viability of burned soil as an
organic soil amendment. It is known for its quick growth and nutritional value.
Pechay (Brassica rapa) in English pechay is called a “snow cabbage”, “Chinese chard,
or even Chinese cabbage” (philnews. ph), a widely cultivated leafy green vegetable, that enjoys
global popularity as a staple food item. The consumption of this particular food item has been
found to provide a significant amount of essential vitamins, minerals, and dietary fiber.
Chemical fertilizers, which can be costly and harmful to the environment, are typically used to
grow pechay.
Burned soil refers to soil that has undergone exposure to fire. The perception of it being
a barren and unproductive area is a common notion however, recent studies suggest that it holds
significant potential as a valuable asset for agricultural purposes. Elevated nutrient levels
including potassium, phosphorus, and nitrogen, have been observed in soil that has undergone
burning (Northern Arizona University). The essential nutrients required for optimal plant
growth include those found in burned soil, making it a viable option as a natural fertilizer.
Acknowledging that burned soil may potentially harbor hazardous substances, including heavy
3
metals and polycyclic aromatic hydrocarbons (PAHs) is crucial. The potential toxicity of
chemicals to plants and animals necessitates evaluating burned soil before its application as a
fertilizer. Though fire can diminish nutrient pool sizes, nutrient availability often increases. Soil
fertility can increase after low-intensity fires since fire chemically converts nutrients bound in
dead plant tissues and the soil surface to more available forms or the fire indirectly increases
mineralization rates through its impacts on soil microorganisms (Schoch & Binkley, 1986).
There are several potential advantages to using burned soil as fertilizer. The first benefit is that
it is a cheap way to fertilize crops. Second, using organic matter that would otherwise be wasted
makes it a sustainable method of fertilizing crops. In third place, it is a means of lowering the
use of chemical fertilizers.
The purpose of the current study is to assess whether using burned soil as a potential
fertilizer for pechay cultivation is practical. The investigation's main objective is to look into
the possible effects of burned soil on the development and output of pechay plants. The
researchers will test burned soil samples in addition to conducting other analyses to find out
whether there are any potentially hazardous chemicals present. This study's goal is to determine
whether burned soil can be used as a reliable and secure organic fertilizer for pechay cultivation.
Farmers can use this knowledge to produce pechay more sustainably and less dependently on
chemical fertilizers.
Background of the Study
Pechay is a popular crop among home gardeners and small-scale farmers because it is
also relatively easy to grow, and because the town of Lucban is surrounded by numerous
farmlands, many farmers decide to plant it. Pechay (Brassica
Rapa
L.) belongs to the
4
Brassicaceae family and is one of the most famous vegetables in the Philippines. It is also known
to be one of the oldest green vegetables in Asia. Therefore, it plays an important role in the
Philippine economy and the nutrition of the Filipino people. Pechay is mainly used for its young,
immature, but fully expanded leaves. The juicy petiole is usually the first choice. It is used as a
main ingredient in soups and stir-fries. In Chinese cuisine, its green petioles and leaves are also
used as decoration. (Gonzales et al., 2015). Soil is one of the most important aspects of growing
pechay, making sure that it is rich and well-drained. Farmers have historically used chemical
fertilizers to increase soil fertility. However, chemical fertilizers can be expensive and harmful
to the environment.
Chemical fertilizers are synthetic fertilizers created through industrial manufacturing
techniques. They frequently contain high levels of potassium, phosphorus, and nitrogen, which
are vital nutrients for plant growth. Chemical fertilizers have several unfavorable effects on the
environment but can be effective at increasing crop yields. Water pollution is one of the main
effects of chemical fertilizers on the environment. Chemical fertilizers can runoff from fields
and pollute rivers and lakes (Santos et al.,2012). Chemical fertilizers are synthetic fertilizers
that are produced using industrial processes. Growing interest in employing organic fertilizers
to increase soil fertility has been observed recently. Natural substances like compost, animal
manure, and plant remains are used to make organic fertilizers. They can help to improve the
long-term health of the soil and are more eco-friendly than chemical fertilizers.
One of the potential organic fertilizers is the burned soil. The burned soil can occur
naturally, as in the case of wildfires, or intentionally, as in the case of slash-and-burn agriculture.
Several physical soil qualities, including soil structure, texture, porosity, wettability, infiltration
5
rates, and water-holding capacity, can be altered by fire. The extent to which fire affects various
soil physical qualities is determined by fire intensity, severity, and frequency. Low-intensity
fires do not burn the soil sufficiently to induce major changes in its physical qualities (Northern
Arizona University).
The use of burned soil as fertilizer has several advantages. The first benefit is that it is a
cheap way to fertilize crops. Organic waste materials like manure or plant remnants can be used
to create burned soil. Second, burning soil is a sustainable way to fertilize crops, which can help
farmers save a lot of money on fertilizer costs. Third, burned soil can help to improve the quality
of the soil because it uses organic matter that would otherwise be wasted and does not degrade
the soil or water. Soil that has been burned can become more fertile and alkaline. Plant growth
may be facilitated as a result, of increasing crop yields.
Additionally, there are some difficulties with using burned soil as fertilizer. One
difficulty is that depending on the type of organic matter burned, the nutrient content of the soil
that has been burned can vary. Farmers may find it challenging to estimate the amount of burned
soil to apply to their crops as a result. Burned soil may contain hazardous substances like heavy
metals and polycyclic aromatic hydrocarbons (PAHs), which presents another problem
(Northern Arizona University). High concentrations of burned soil can contaminate crops and
render them unfit for human consumption.
To grow pechay more sustainably, burned soil may be used as a natural fertilizer.
Compared to chemical fertilizers, burned soil has several advantages, including being less
expensive, more environmentally friendly, and better for the soil.
6
Statement of the Problem
The study generally aimed to determine the potential of Burned Soil as a Natural Fertilizer
for the Cultivation of Pechay (Brassica rapa). Specifically, it seems to answer the following
questions:
1. What are the physical characteristics of burned soil by which biodegradable
wastes are combusted in terms of:
1.1 Color
1.2 Texture
1.3 Moisture Content
1.4 Acidity
2. What are the physical characteristics of burned soil by which non-biodegradable
wastes are combusted in terms of:
2.1 Color
2.2 Texture
2.3 Moisture Content
2.4 Acidity
3.
What is the effect of commercial fertilizer on the cultivation of pechay in terms
of:
3.1 Plant height
3.2 Number of leaves
3.3 Leaf area
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3.4 Fresh weight
3.5 Dry weight
4. What is the effect of burned soil with biodegradable wastes on the cultivation of
pechay in terms of:
4.1 Plant height
4.2 Number of leaves
4.3 Leaf area
4.4 Fresh weight
4.5 Dry weight
5. What is the effect of burned soil with non-biodegradable wastes on the cultivation
of pechay in terms of:
5.1 Plant height
5.2 Number of leaves
5.3 Leaf area
5.4 Fresh weight
5.5 Dry weight
6. Is there a significant difference among the cultivation of the three groups of pechay
plants?
Hypothesis
There is no significant difference among the cultivation of the pechay plant in the three
groups, i.e., burned soil with biodegradable wastes, burned soil with non-biodegradable wastes,
and the group with commercial fertilizer.
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Significance of the Study
This study will be beneficial to the following:
Community. This study provides knowledge evaluating the viability of utilizing burned
soil as a potential medium for pechay cultivation.
Farmers. This research study will give an idea about the effectiveness of burned soil on
their plants, which supplies the vegetables with the nutrients they need.
Researchers. This study will provide insight and knowledge about the nutrient attributes of
burned soil. Technically, researchers would gain information about a certain topic, and it would
also help them to know the effectiveness of burned soil on petchay.
Future researcher. This will serve as a guide for future researchers. Additionally, this can
be used as a basis and additional reference for further related studies.
Scope and Limitation
This study was limited only to the selected parameters mentioned in the statement of
the problem that is deemed important to determine the effect of burned soil on the cultivation
of pechay. Variables like nutrient content, potential changes in taste or edibility, and its potential
for harmful substances were not determined. Also, other parameters such as pest and disease
ratings were not determined.
Definition of Terms
To facilitate understanding of this study, different terms are defined herein conceptually
and operationally.
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Cultivation. The act of taking care of or raising plants is the conceptual definition of this term.
You'll be doing a lot of cultivation if you decide to grow your fruits and vegetables in the
backyard. (According to Merriam-Webster). Operationally speaking, farming is the care and
harvesting of plants and other vegetables.
Biodegradable. The type of substance that can be decomposed naturally by the organisms in
an ecosystem is the conceptual definition of this term. Simply put, the term "biodegradable"
refers to a substance that naturally disintegrates into smaller parts like gases and sugars.
Microorganisms, such as bacteria and fungi, undergo biodegradation. (According to MerriamWebster). In an operative meaning, it is something that can break or decompose something like
fruit peels or papers.
Non-biodegradable. A type of substance that cannot be broken down by natural organisms
and serves as a source of pollution was conceptually defined by this term. These waste products
are unable to be broken down or dissolved by natural processes. (According to MerriamWebster). Operationally defined as a recognized thing or something that cannot break down or
disintegrate and can harm people, animals, and the environment
Commercial fertilizer. Conceptually, this term is defined as a chemical mixture made
specifically for use as fertilizer, as opposed to things like farm manures that are naturally
occurring. (According to Merriam-Webster). It is a kind of chemical, operationally defined as
a kind of typical fertilizer used by most farmers.
Combustion. Conceptually, this term refers to the act of burning something or a chemical
reaction that produces heat when a substance reacts quickly with oxygen. (According to
Merriam-Webster). Operationally defined as a procedure whereby any object is burned.
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Attribute. Conceptually speaking, this phrase refers to a quality, character, or characteristic
that is ascribed to someone or something. (According to Merriam-Webster). Operationally used
to understand the characteristics that something or someone has conceptually.
Viability. The ability to survive, particularly under particular circumstances, is how this term
is conceptually defined. (According to Merriam-Webster). Whether something or someone can
live is operationally defined.
Burned Soil. Burnt soil is essentially dense, gooey clay that has undergone a heating process
to alter its structural characteristics. It is frequently combined with compost, which creates the
growing mix's organic, water-retentive component. For the majority of plants, a growing
mixture
composed
of
1-part
burnt
soil
and
1-part
compost
works
best.
(FarEastFloraGardencentre cites). Burned soil is operationally defined as a type of soil that has
undergone burning and has different moisture content and texture as a result.
Pechay. A vegetable plant known as pechay has small, green leaves with white stalks. It is
frequently referred to as bok choy. The country where this vegetable grows is tropical.
according to blogspot.com. Operationally, the term refers to a particular kind of vegetable that
is typically grown in the Philippines and is a white, green vegetable.
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Chapter II
Review of Related Literature and Studies
The importance of this chapter is all about determining related literature and studies
undertaken by professionals about the same topic. The researchers reviewed some studies that
provide important details on the modality and views on the essentials of the study. The related
arrangements and information were in one way related, and the other related to some prospects
of the existing effort, which added to its relevance
Natural disturbances like fire have had a significant impact on the ecology and
structure of numerous ecosystems, including forests. Plant growth, nutrient cycling, and soil
health can all be significantly impacted by fire. The intensity and frequency of the fire, the type
of soil, and the vegetation cover are just a few of the variables that affect how fire affects soil
properties. High-intensity fires can burn through a lot of organic matter in the soil, which can
result in less readily available nutrients and more soil erosion. Low-intensity fires, however,
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can also enhance soil qualities, such as enhancing soil structure and increasing nutrient
availability.
Several variables, including the type of plant, the intensity of the fire, and the
environment after the fire, influence how fire affects plant growth. Due to their fire resistance,
some plants can take advantage of the increased nutrient availability that follows a fire. Other
plants could be harmed by fire because they are not fire-adapted.
Burned Soil
According to Northern Arizona University, fire can have a significant impact on
soil macronutrients, soil organic matter, and soil physical properties. Fire can release nutrients
from soil organic matter into the soil, making them more available to plants. However, fire can
also volatilize nutrients, such as nitrogen and sulfur, and reduce the overall nutrient content of
the soil. Fire can consume soil organic matter, which can reduce the soil's fertility and waterholding capacity. Fire can also alter the chemical composition of soil organic matter, which can
affect nutrient availability and soil structure. Fire can reduce soil porosity and increase soil bulk
density. This can decrease water infiltration rates and water-holding capacity, and make the soil
more susceptible to erosion. Fire can also create water-repellent layers on the soil surface, which
can further reduce infiltration and increase runoff. The overall impacts of fire on soil
macronutrients, soil organic matter, and soil physical properties depend on the intensity of the
fire. Severe fires can have more negative impacts on soil health than low-intensity fires. Fire
13
managers need to consider the potential impacts of fire on soil health when planning and
implementing fire management activities. In areas where soil health is already compromised,
managers may want to avoid using fire or to use low-intensity fires. In areas where soil health
is not a concern, managers may be able to use fire to improve soil health, but they need to be
careful to avoid severe fires. Post-fire management activities can help to mitigate the negative
impacts of fire on soil health. For example, managers can seed native plants to help restore
vegetation cover and reduce erosion. They can also apply fertilizer to help replenish the
nutrients that were lost in the fire.
Also, according to Debano (2013), fire affects nutrient cycling and the physical,
chemical, and biological properties of soils occupied by western-montane forests. Fire can
increase the availability of some nutrients in the soil, such as potassium, calcium, and
magnesium. However, fire can also volatilize other nutrients, such as nitrogen, phosphorus, and
sulfur. This can lead to nutrient losses over time. Fire can reduce soil porosity and increase soil
bulk density. This can make the soil more susceptible to erosion and reduce its ability to hold
water. Fire can also create water-repellent layers on the soil surface, which can further reduce
infiltration and increase runoff. Fire can alter the chemical composition of soil, including pH,
cation exchange capacity, and organic matter content. These changes can affect nutrient
availability and plant growth. Fire can kill soil microorganisms, which can reduce nutrient
cycling and soil fertility. However, fire can also stimulate the growth of some beneficial
microorganisms. Nitrogen replenishment is important after fire to prevent nutrient losses and
maintain soil fertility. Post-fire management activities can also help to mitigate the negative
effects of fire on soil properties, such as erosion and water repellency. Overall, the effects of
fire on soil properties in western-montane forests depend on the intensity and frequency of the
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fire. Severe fires can have more negative impacts on soil health than low-intensity fires. Fire
acts as a rapid mineralizing agent, releasing nutrients instantaneously as contrasted to natural
decomposition processes, which may require years or, in some cases, decades. The amount of
litter, duff, and humus combusted depends on the duration and intensity of the heat flux reaching
the litter layer. Soil temperatures generated during fires vary considerably, depending on the
fuel load and the burning conditions. If a large amount of fuel is present, soil temperatures can
remain high for several hours and would be expected to produce large changes in soil chemical,
physical, and biological properties.
Badia et al. (2014) emphasized that changes in water repellency, aggregation, and organic
matter of a mollic horizon burned in the laboratory: Soil depth affected by fire takes a different
tack. The study found that moderate burning of Rendzic Phaeozem soil in the laboratory
produced changes in water repellency (WR), soil aggregate stability (SAS), and organic matter
only up to 2 cm depth. Specifically, the following changes were observed: O horizon:
Immediate and significant decrease in WR, total organic carbon (TOC), and pyrolyzed carbon
(PyC), Ah horizon (0-1 cm depth): Decrease in WR and PyC, No significant change in TOC,
Ah horizon (2-3 cm depth): Decrease in SAS. The study also found that fire modified the
structural composition of organic matter, with a decrease in the relative abundance of typical
vegetation markers and lignin markers, and fragmentation of long-chain molecules. The results
of this study suggest that moderate burning of Rendzic Phaeozem soil has relatively superficial
effects on soil properties. However, it is important to note that the study was conducted in the
laboratory under controlled conditions. The effects of fire on soil properties in the field may be
more severe, depending on factors such as fire intensity, soil type, and vegetation cover.
15
However, in a dry forest in Bolivia, the effects of high- and low-intensity fires on soil
characteristics and plant growth (Kennard et al., 2001). The study found that high-intensity fires
significantly increased soil pH, concentrations of extractable calcium (Ca), potassium (K),
magnesium (Mg), and phosphorus (P), and amounts of resin-available P and nitrogen (N) in a
tropical dry forest in Bolivia. Low-intensity fires also increased soil nutrient availability but to
a lesser degree. Despite the loss of soil organic matter during high-intensity fires, which can
lead to increased bulk density and strength, and decreased water infiltration rates, growth of
Anadenanthera colubrina seedlings was greater following high-intensity fires. This suggests
that the increase in nutrient availability caused by high-intensity fires was not offset by degraded
soil structure in its effects on seedling growth. The results of this study suggest that highintensity fires can have a positive impact on plant growth in tropical dry forests, at least in the
short term. However, further research is needed to understand the long-term effects of highintensity fires on soil health and plant growth. Fire managers need to consider the potential
impacts of fire on soil health and plant growth when planning and implementing fire
management activities. In tropical dry forests, where soil nutrients are often limited, highintensity fires may be used as a tool to increase nutrient availability and promote plant growth.
However, it is important to monitor the long-term effects of high-intensity fires on soil health
to ensure that they are not sustainable in the long term.
Another strategy Effects of soil burn severity on maritime pine seedling
germination and early establishment, in two different experimentally burned soils, under
greenhouse conditions (Vega et al., 2011). The study found that high soil burn severity in
coarse-textured soils delayed germination, increased mortality, and temporarily decreased the
height of maritime pine seedlings in the first year after sowing. This response was affected by
16
a number of factors, including soil heating level, soil carbon consumption, post-fire soil carbon,
depth of burn, and post-fire duff depth. Ash did not influence the above processes. The study
also found that the variability in the response of regeneration variables in the heavy-textured
soils could not be explained by the factors that were measured. The results of this study suggest
that soil burn severity can have a significant impact on the initial establishment of maritime
pine, especially in coarse-textured soils. Managers need to be aware of the potential negative
effects of high soil burn severity on maritime pine regeneration when planning and
implementing fire management activities. Further research is needed to better understand the
effects of soil burn severity on maritime pine regeneration in heavy-textured soils. The
applicability of the results of this study to field conditions is limited by the fact that the study
was conducted in a greenhouse under controlled conditions. However, the study provides
valuable insights into the potential effects of soil burn severity on maritime pine regeneration.
Managers can use the results of this study to inform their fire management decisions. For
example, they may want to avoid using high-intensity fires in areas where maritime pine
regeneration is a priority. They may also want to monitor soil burn severity after fires to assess
the potential impact on maritime pine regeneration.
Pechay
Napa cabbage (Brassica rapa, var. pekinensis), also called “pechay baguio” in
the Philippines, is a form of Chinese cabbage cultivated for its edible leaves. Napa cabbage is
widely grown in eastern Asia and is commonly used to make kimchi, a traditional Korean dish
made of spicy fermented vegetables (Department of Science and Technology). The study of
Garcia et al. (2016), "The effect of different levels of nitrogen, phosphorus, and potassium on
17
the growth and yield of pechay (Brassica rapa chinensis L.)" shows that different levels of
nitrogen (N), phosphorus (P), and potassium (K) on the growth and yield of pechay (Brassica
rapa chinensis L.) were investigated in a field experiment. The treatments were: (1) NPK 100%
(recommended rate), (2) NPK 75%, (3) NPK 50%, and (4) 0% NPK. The results showed that
the NPK 100% treatment had the highest yield, followed by the NPK 75% treatment, the NPK
50% treatment, and the 0% NPK treatment. On the other hand, Gonzales et al., (2015) study of
"Response of Pechay (Brassica napus L.) to Different Levels of Compost Fertilizer" concluded
that the application of T4 (75% Pure Garden Soil: 25% Pure Compost provided the best growth
and yield performance of pechay in terms of leaf area and fresh weight. This implies that the
limiting percentage of burned soil designed to be a fertilizer for pechay is only 25% in order to
have an ideal growth rate for the plant.
Fertilizer
Pahalvida et. al., (2021) added, chemical fertilizers are of various types in the form
of nitrogenous, phosphate, and potassium fertilizers. The employment of fertilizers not only
increases crop productivity but also alters soil physicochemical and biological properties.
However, imbalanced use of chemical fertilizers can alter soil pH, and increase pest attacks,
acidification, and soil crust, which results in a decrease in soil organic carbon and useful
organisms, stunting plant growth and yield, and even leading to the emission of greenhouse
gases, retrieved from Krasilnikov et al., (2022).
Synthesis
18
Nau.edu) The macronutrients, organic matter, and physical characteristics of soil can all be
significantly impacted by fire. Plants can have greater access to nutrients in the soil when soil
organic matter is burned. Furthermore, citing (Leonard, 2013). The physical, chemical, and
biological characteristics of the soils that support western montane forests are impacted by fire,
as is the cycling of nutrients. A fire can make certain nutrients more accessible in the soil,
including magnesium, calcium, and potassium. Nevertheless, additional nutrients like sulfur,
phosphorus, and nitrogen can also be volatilized by fire. Over time, this may result in nutritional
losses. In his research, (David Badia et al. 2014) discovered that fire altered the structural
makeup of organic materials, resulting in long-chain molecule fragmentation and a drop in the
relative abundance of lignin and characteristic vegetation indicators. According to (D. K.
Kennard et al. 2001), the impacts of deteriorated soil structure on seedling growth were not
greater than the increase in nutrient availability brought on by high-intensity fires. The study's
findings imply that, at least temporarily, high-intensity fires may benefit plant development in
tropical dry forests. High soil burn intensity in coarse-textured soils was observed by J. A.
Vega et al. to cause delays in germination, increase mortality, and momentarily reduce the
height of maritime pine seedlings in the first year following sowing. Numerous variables, such
as the depth of burn, post-fire duff depth, post-fire carbon consumption, and soil heating level,
influenced this response. Ash had no bearing on the procedures mentioned above.
The availability of nutrients, the amount of organic matter in the soil, and its physical
qualities are all significantly and intricately impacted by fire. Although fire might make some
nutrients more accessible at first, volatilization can result in long-term nutritional losses. Fire
has a complex impact on plant growth that can have both beneficial and detrimental effects. In
certain habitats, high-intensity fires can help plant development temporarily, but in other
19
environments, they can cause seedling height reduction, germination delays, and an increase in
mortality. Many variables, such as soil texture, burn severity, and post-fire circumstances,
influence how a fire affects plant communities overall. To manage forest ecosystems and
encourage sustainable plant development, it is essential to comprehend the intricate
relationships that exist between fire and soil qualities.
Pahalvida et. al. 2021 added chemical fertilizers of various types in the form of
nitrogenous, phosphate, and potassium fertilizers. The employment of fertilizers not only
increases crop productivity but also alters soil physicochemical and biological properties. He
discussed that chemical fertilizers contain nitrogen, potassium, and phosphorus, which are the
absolute nutrients needed for pechay plantations. Apparently, according to his study, it alters
the soil's physicochemical properties, which deeply affect the biological quality of the soil.
Additionally, chemical fertilizers deteriorate the natural ability of soil to produce high
organic yields in the field of agriculture, which is why the researcher proposed a fertilizer that
can help harvest a high quality of pechay and yet does not degrade the natural properties of soil.
The side effects of chemical fertilizer are extremely dangerous in our environment imbalanced
use of it can alter soil pH, and increase pest attacks, acidification, and soil crust, which results
in a decrease in soil organic carbon and useful organisms, stunting plant growth and yield, and
even leading to the emission of greenhouse gases, retrieved from Krasilnikov et. al. 2022.
Chemical fertilizers can drastically change the physicochemical and biological features
of soil, even though they are successful at increasing crop output. Applying fertilizers high in
nitrogen, phosphate, and potassium—nutrients vital to pechay plantations—can have a
significant effect on the condition of the soil. The study by Pahalvida et al. emphasizes the
20
necessity of using fertilizer more comprehensively, taking into account its long-term effects on
soil sustainability and quality.
(KAINpormasyon) Napa cabbage (Brassica rapa, var. pekinensis), also called pechay
Baguio in the Philippines, is a form of Chinese cabbage that is, cultivated for its edible leaves.
Napa cabbage is widely grown in eastern Asia and is commonly used to make kimchi, a
traditional Korean". By synthesizing, the website provides insights into the historical and
cultural significance of petchay, examining its global popularity and regional variations.
Theoretical Framework
Forest fires usually decrease the total nutrient pool on a site (the total amount of
nutrients present) through some combination of oxidation, volatilization, ash transport,
leaching, and erosion. For example, volatilization and oxidation in a low-intensity slash fire
reduced fuel nutrient pools in understory and forest floor: 54-75% of N, 37–50% of P, 43–66%
of K, 31–34% of Ca, 25–49% of Mg, 25–43% Mn, and 35–54% of B (Raison et al., 1985).
Though fire can diminish nutrient pool sizes, nutrient availability often increases. Soil fertility
can increase after low-intensity fires since fire chemically converts nutrients bound in dead
plant tissues and the soil surface to more available forms or the fire indirectly increases
mineralization rates through its impacts on soil microorganisms (Schoch & Binkley, 1986).
Some nutrient dynamics are more sensitive to fires than others. The concentration of
potassium, calcium, and magnesium ions in the soil can increase or be unaffected by fires
whereas nitrogen and Sulphur often decrease (Hough, 1981). Although the relationship
21
between fire and soil nutrients is complex because of the interactions among many factors, fire
intensity is usually the most critical factor affecting post-fire nutrient dynamics, with greater
nutrient losses occurring with higher fire intensity. Fire intensity both directly and indirectly
impacts many of the mechanisms that affect nutrient pools and cycling. Fire temperature
directly determines the amounts and kinds of nutrients that will be volatilized. Nutrients are
abundant in superficial organic soil layers, and the amount of these layers consumed is
proportional to fire intensity. As an indirect effect, the physical transport of nutrients off-site
is related to fire intensity. Convective transport of ash varies from 1% in low-intensity fires to
11% in high-intensity fires (Neary et al., 1999). High-intensity fires can also change the
physical characteristics of the soil making it more susceptible to nutrient loss through erosion
(McColl and Grigal 1977). The impact of fire on site productivity is also related to intensity.
While high-intensity fires tend to decrease site productivity, low-intensity fires can increase
site productivity (Carter & Foster, 2003).
Conceptual Framework
Figure 1.
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Input
Burned Soil
Process
1)The process of identifying
the selected soil sample and
subjecting it to combustion
2)The process of planting 1825 seed of pechay and planting
it.
3)The investigation involved
the observation and analysis of
seed growth and germination
4)The investigation involved
the observation of the plants
presence during the process.
5)Analyze and test for the
parameters of color, texture,
moisture, acidity, plant height
leaf area, no. of leaves, dry and
fresh weight.
Output
Burned Soil
Fertilizer for
Pechay
Figure 1. Burned Soil: Its Potential as a Natural fertilizer for the cultivation of Pechay
(Brassica Rapa)
Figure 1 shows the study's input, process, and output as its conceptual framework or
basis. As input, pechay cultivation and burned soil were used. Similarly to that, the procedure
entails identifying the chosen soil sample, burning it, and then planting 18–25 pechay seeds.
Observation and evaluation of seed germination and growth. The investigation included
observing the presence of the plants throughout the process, followed by an analysis and testing
for any potential changes in flavor or edibility. On the other hand, the output is the creation of
burned soil fertilizer for pechay.
Chapter III
23
Research Methodology
This chapter presents the methodology and procedure applicable for conducting the
study. It discussed the research design, research locale, population and sampling, research
instrument, data gathering procedure, and statistical treatment that were used in the study.
Research Design
The research entitled “Burned Soil: Its Potential as a Natural Fertilizer for the
Cultivation of Pechay (Brassica Rapa)” is an experimental research design to evaluate the
viability of utilizing burned soil as a natural fertilizer for pechay plants’ growth and yield.
In an experimental research, independent and dependent variables are being determined. In this
research, the independent variable is the burned soil, while its effects on pechay cultivation is
the dependent variable. Furthermore, this is a true-experimental research design wherein the
researchers will analyze the gathered data through applying methods of systematic approach
that involves mathematical models.
This study would test the effectiveness of burned soil as a natural fertilizer for pechay
cultivation through determining its physical characteristics such as color, texture, moisture
content, and acidity, by which one set is combusted with biodegradable wastes and another with
non-biodegradable wastes.
Research Locale
The study will be conducted at a farm, located at Brgy. Palola, Lucban, Quezon.
The researchers will employ observation method on the pechay plants being planted at the farm
to gather necessary data.
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RESEARCH RESPONDENTS AND SAMPLING TECHNIQUE
The research study is focusing on the effectiveness of burned soil on pechay
plant growth. Therefore, respondents and sampling techniques will no longer be applied. In
addition, the subjects of this study are pechay and burned soil, which can be classified into two
categories: inorganic burned and organic burned soil.
Materials and Methods
In investigating the potential of burned soil as a natural fertilizer for pechay
(Brassica rapa), the study will follow structured methods and utilize specific materials. Burned
soil samples are obtained from burning biodegradable waste, while the other samples are
obtained from burning non-biodegradable waste, serving as a comparative reference. The soil
samples underwent rigorous preparation, including the removal of debris and thorough drying
to eliminate excess moisture, before being subjected to a series of soil tests. These tests involved
assessing pH levels using a calibrated pH meter and analyzing nutrient content, encompassing
crucial elements such as nitrogen, phosphorus, and potassium fertilizers.
The experimental setup involved the utilization of different sets of planted
Pechay filled with combusted biodegradable waste in soil and combusted non-biodegradable
waste in soil. Each seed of Pechay will be planted in a set of combusted biodegradable waste
and non-biodegradable waste, and throughout the growth cycle, measuring tools for plant
growth will be used, such as a ruler, measuring tape, pH meter, weighting scale and soil testing
kits for initial For the watering system, a watering can, host, fauset and sprayer will be used. In
monitoring the pechay plants, it will include meticulously recording critical parameters such as
plant height, number of leaves, leaf area, fresh weight, and dry weight. Upon completion of a
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predefined growth period, the soil will undergo further analysis to evaluate changes in nutrient
levels, color, texture, moisture content, and any alterations in soil composition following plant
growth. And for labeling materials, we need materials such as tags and markers for proper
identification of each set of fertilizer.
The data gathered comprised initial soil test results, continuous measurements of
plant growth, and subsequent soil analysis to compare the growth parameters and soil
characteristics between the combusted biodegradable and non-biodegradable. Then, a
comprehensive interpretation of these analyses aimed to draw conclusive insights into the
effectiveness of burned soil as a natural fertilizer for pechay. The study's findings, limitations,
and implications were carefully examined and presented to contribute to the understanding of
burned soil's potential as a viable fertilizer for optimizing pechay cultivation.
Research Instrument
The research instrument for collecting and gathering data is observation. In this case,
the observation is focused on plant growth and the effect of burned soil. The researchers are
required to observe, take notes on what they have seen, and list down any changes to plant
without manipulating any of the variables to provide highly accurate data.
Data Gathering Procedure
The study tested the effectiveness of burned soil made from both biodegradable and
non-biodegradable garbage may be a useful substitute for commercial fertilizer for growing
pechay. Pechay plants grown in various soil treatments were observed and their plant growth
parameters (plant height, number of leaves, leaf area) and yield parameters (fresh weight, dry
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weight) compared. Burned soil from non-biodegradable waste, burned soil from biodegradable
waste, and commercial fertilizer were also compared. The project will offer insightful
information about these waste materials' potential as long-term soil additions.
In order to address questions 1 and 2, the following criteria pertaining to color, texture,
moisture content, and acidity will be measured or determined in order to establish the properties
of the burned soil that are both biodegradable and non-biodegradable when they burn. In order
to produce a reliable analysis, the researchers will only examine the color and texture with their
senses of touch and sight. They will also utilize tools like tensiometers to measure the moisture
content and soil pH meters to measure the acidity of the soil.
To respond to questions 3, 4, and 5 regarding the effects of burned soil on the growth
of pechay in terms of plant height, number of leaves, leaf area, fresh weight, and dry weight,
three distinct subjects—commercial fertilizer, biodegradable waste, and non-biodegradable
waste—will be discussed. In order to measure the height of the plants, the researchers will use
a ruler or other measuring tool. They will also count the leaves to find out how many there are,
weigh the fresh weight of the plants immediately after cultivation, dry the plants to determine
their dry weight, and measure the area of the leaves using an LP-80 ceptometer.
The researchers will compare each of the following test subject data collection
characteristics in order to respond to question 6.
However, because they lack several necessary instruments, such tensiometers, pH
meters, and LP-80 ceptometers, the researchers will have to ask the SLSU College of
Agriculture for permission to perform the parameter tests that they were unable to perform
because of their lack of equipment. To provide the college department with proof of compliance,
the researchers will draft and sign a letter addressed to the practical research adviser.
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Data Analysis
The data will be analyzed by comparing numerous types of planted pechay sets cultivated
with different fertilizers. This involves a comprehensive data analysis employing both
ANOVA (Analysis of Variance) and the MM (Morrison-McCullagh) formula. ANOVA
analysis of variance will be utilized to assess any significant differences in plant growth in
terms of height, leaf size, color, number of leaves, leaf area and soil nutrient content among
various soil treatment including (A. burned soil with biodegradable waste, B. burned soil
with non-biodegradable waste and C, just burned soil). MM formula is a mathematical
model used to estimate the potential impact of a treatment will be employed, and
estimating the potential effects of burned soil as natural fertilizer on specific response
variables, such as plant growth metrics like plant height, leaf size, color, number of leaves,
leaf area. This mathematical tool enables the extrapolation of experimental data, offering
insights into the potential efficacy of burned soil as a natural fertilizer in comparison to
other soil treatments. By integrating these statistical and predictive methodologies, this
analysis aims to determine the most effective fertilizer(s) for promoting advanced growth
and optimizing the cultivation of pechay.
This process requires a comparative assessment of the collected data points and patterns
that distinguish the impact of each fertilizer type on pechay growth. Using a statistical
approach for accuracy makes it easier to identify any significant differences or correlations
between the various sets of fertilizers. Ultimately, this analysis aims to determine the most
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effective fertilizer(s) for promoting advanced growth and optimizing the cultivation of
pechay.
The investigation into the potential of burned soil as a natural fertilizer