Research article
Rice Straw Availability and Postharvest
Management Practices of
Select Rice Farmers
in Isabela, Philippines
Jeffrey
C. Ginez*1,2 and Marcelino U.
Siladan2
1Faculty of General Education
and Experiential Learning, Philippine Normal University-Manila, Philippines
2 Department
of Sustainability and Environment, Miriam College, Quezon City, Philippines
Received: 20-11-2025 Accepted: 20-12-2025 Published online: 29-12-2025
DOI: https://doi.org/10.33687/ricosbiol.03.012.79
Abstract
The prevalent use of combine harvesters challenges rice farmers to efficiently
manage rice straw. There is also an extremely low adoption of sustainable rice straw
management by rice farmers. Hence, estimation of the total straw biomass and determination
of rice straw management practices are necessary. The main objective of this study
was to assess the availability of rice straw and postharvest management options
of rice farmers. A case study was employed. Data gathered from household surveys
and analyzed through descriptive statistics. Analysis revealed that the mean straw
biomass ha-1 is 5,219.73 kg. Moreover, the type of soil and planting
method influenced the generation of higher quantities of rice straw. In addition,
sex, household size, rice production training, farm organization, land ownership,
machine ownership, road structure, and type of soil showed a significant relationship
to the postharvest management practices of rice farmers. Lastly, rice farmers predominantly
practiced in-situ straw incorporation, but only a few practiced crop rotation, rice
ratooning, straw mushroom production, and surface retention. It has been demonstrated
that there is a massive contribution of rice straw biomass in Isabela. This provided
data for authorities to implement plans and initiatives and for rice farmers to
employ appropriate management to optimize the potentials of rice straw for a circular
economy. The findings suggest that political will, partnership and collaboration,
provision of physical infrastructures, and active participation of rice farmers
are the key factors to the efficient rice straw management. Through this, rice farmers
can strengthen their technical efficiency and can cultivate environmental efficiency.
Keywords:
Climate
change mitigation, environmental efficiency, rice straw biomass, rice straw management,
straw grain ratio.
Introduction
Mechanization has become a key feature in the major rice-farm activities.
This involves the use of a combine harvester for harvesting
and threshing. This
shift is replacing the traditional methods that relied on portable axial threshers.
The use of combine harvesters has provided convenience to the rice farmers. Consequently,
the increasing adoption of combine harvesters in the Philippines has impacted the
economic aspect of the rice farmers, such as labor efficiency and reducing postharvest
losses by 2.2%, as reported by the International Rice Research Institute (IRRI,
2016). This technological advancement highlights the importance of mechanization
in enhancing productivity and sustainability in rice farming.
The introduction
of combine harvesters has led to a new challenge for
rice farmers managing the loose and spread rice straw (RS) left in the rice field (Allen et al., 2020). To better understand
the scope of this issue, various studies were conducted to determine the annual generation of rice
straw globally. Table 1 shows the total annual RS generation, which varied significantly across countries, regions, and worldwide. It reflects that the total RS annual generation varies from one participating country
to another, varies in reference to the total RS annual generation in the region,
and varies in relation to the total RS annual generation in the world. Comparing
the total RS annual generation of the Philippines against the annual total RS generation
of the other countries, Thailand generated twice as much, and India generated almost
five times as much, while Vietnam relatively shared almost the same amount. Thus,
the Philippines shows the lowest generation of RS annually among these countries. Following these data, it is undeniable that the
total RS annual generation in the regions and in the world is a considerably large
amount. Thus, it is considered a big agricultural waste (Dominguez-Escriba and Porcar,
2010).
Table 1: Annual Generation of RS in the Various Parts of
the World in Metric tons (Mt)
|
Location of the Study |
Annual Generation of RS |
Source |
|
South
Asia |
5 - 6 t |
Mandal
et al. (2004) |
|
World |
About 800 Mt |
Dominguez-Escriba and Porcar (2010) |
|
Vietnam |
24 Mt |
Nguyen
et al. (2016) |
|
India |
97.19 Mt |
Bhattacharyya
and Padhi (2019) |
|
Thailand |
21.86 Mt |
Bhattacharyya
and Padhi (2019) |
|
Philippines |
10.68 Mt |
Bhattacharya
and Padhi (2019) |
|
Southeast
Asia |
100 - 400 Mt |
Gummert
et al. (2020) |
|
Asia |
330 - 470 Mt |
Gummert
et al. (2020) |
|
World |
370 - 520 Mt |
Gummert et al. (2020) |
Crop residues, including RS and stubbles, are considered agricultural waste
if not properly managed. This underscores the need for efficient management of RS.
Various scientific studies have determined the wide array of RS management options
which are both economic and environmental friendly. Among these RS management strategies are mechanized
collection of rice straw (Balingbing et al. 2020), straw
incorporation (Mannepitak et al. 2019), surface retention
(Bimbraw, 2019), composting (Romasanta
et al. 2017), mushroom production (Nguyen et al. 2016), fodder (Sheikh et al. 2018),
sources of energy (Swain et al. 2019; Bhattacharyya et al. 2020), production of
paper (Kaur, Bhardwaj & Lohchab, 2017), and production
of biochar (Bhattacharyya et al. 2020). These different
methods of managing RS offer sustainable and promising options for reducing the environmental impact of rice
production and potentially mitigating its carbon footprint.
According to the United States Environmental Protection Agency (US
EPA, 2020), the global greenhouse gas (GHG) emissions showed 54.59 billion tons
(Bt) of CO2 equivalent (e). In the Philippines, Climate Transparency
(2021) reported that the GHG emissions are 269.93 million Mt CO2e. The
energy sector contributed the highest GHG contribution with 52%, followed by agriculture
with 32%, while industrial processes contributed 8%, waste accounted for 7%, and land-use change and forestry contributed
1% (Global Climate Change, 2016). Following that, agriculture contributed the second largest emission
in the major sectoral GHG contribution, rice cultivation, livestock manure, enteric
fermentation, use of synthetic fertilizer, and crop residues are the main sources
of GHG emissions in the Philippines Overall, the agriculture sector in the Philippines
generated a total of 55 Mt CO2e (Climate Transparency, 2021). In the
recent study conducted by Ginez and Siladan (2025), they found out that the overall
carbon footprint of rice farming in Isabela during the dry season was 5,017.80 kg
CO2e ha-1, with soil emissions from methane (CH4)
and nitrous oxide (N2O) contributing 3,953.79 kg CO2e ha-1
. This significant generation of GHGs is attributed to the improper management
of RS in rice paddies, specifically in-situ straw incorporation.
Absence or insufficient or inappropriate rice straw (RS) management can lead to an increase in the carbon footprint
in the rice sector. This results in the intensification of the effects of climate
change in the agriculture sector, greatly affecting the rice farmers and rice production
in the country. Hence, this study aimed to estimate the localized generation of
RS by rice farmers in Isabela. By determining the contribution of RS and postharvest
management practices of the said province, it can contribute to the efficient management
of RS. Specifically, the
study's objectives (aims) were:
1. To estimate
the total straw biomass of rough grain yield ha-1 generated by rice farmers
during the year 2024 dry season;
2. To identify the different
factors that contribute to the high generation of rice straw quantities; and
3. To determine the current
postharvest management practices of rice farmers and factors influencing the implementation of postharvest management options.
Material
and methods
To attain
the objectives of the study, a case study research design was employed. Data were
collected through household surveys conducted via interviews. In the selection of
study sites, the researchers determined the top five municipalities in Isabela,
Philippines with the largest production area and volume of production. These municipalities
were Alicia, the City of Cauayan,
Ramon, the City of Santiago, and San Mateo. They represented 34.23% of the total
rice production area in the province, contributed 259% average yield ha-1,
and shared 34.99% in the overall yield. Figure 1 shows the study sites. The study
focused on the current postharvest management practices of the rice farmers during
the 2024 dry season.
Fig. 1: The Five Study Sites in Isabela (Balingit, 2012) and the Political Map of the Philippines (Wikimedia Foundation, 2024)
Rice farmers
were selected from among the five study sites as participants. The criteria in the
selection of the participants were rice farmers who are owner, tenant or lessee
and cultivates rice paddies with less than one hectare or more for at least five
years. The participants were purposely selected from the list of farmers provided
by the Municipal Agriculture Office, with the help of the Barangay Councilor in
charge of agriculture.
The instrument
used in this study was validated twice by two sets of validators to ensure its reliability
and validity. In estimating the total straw biomass of rough grain yield, it used
the straw grain ratio (SGR) model developed by Nguyen et al. (2020) as part of the
International Rice Research Institute (IRRI) study. The SGR model was applied to
determine the total biomass generated in rice cultivation. The total yield ha-1
was multiplied with the mean yield mass sack-1 to estimate the
total mass of grain yield ha-1.
Then, the value of SGR of 0.74 to 0.79 was multiplied by the rough grain
yield ha-1. It was then calculated through getting the mean of the maximum
and minimum SGR. Data were analyzed and interpreted using descriptive statistics,
including mean, Analysis of Variance (ANOVA), and Pearson correlation coefficient.
Results
Availability of Rice Straw Generated by Rice
Farmers
The harvesting
method employed by all the rice farmers involved the use of a combine harvester
only. Harvesting typically took place in March or April during the dry season. To
calculate the total biomass generated in rice cultivation, the estimated SGR was
used.
The study
discovered that the mean SGR of the total mass of rough grain yield ha-1
is 5,219.73 kg or 5.2t ha-1. Nguyen et al. (2020) reported that the total
biomass ratio of the Philippines ranged from 7.5 to 8t ha-1. The present study's findings correspond to 65-69%
of the aforementioned study. This means that the generation of total biomass straw
of Isabela, Philippines represented a significant amount of rice straw in relation
to the national generation of total straw biomass in 2020. The substantial contribution
of Isabela to the country's rice production, being the second-largest producer,
likely contributed to these results. Transplanting was the common method of planting
employed by the rice farmers during the dry season, which also contributed to the
high generation of rice straw. Hence, the
massive contribution of total straw biomass of Isabela almost represented the national
data on the generation of total straw biomass.
Test of Difference on the Total Straw Biomass
Generated Ha-1 in the Indicated Variables
The test of difference on the mean total straw biomass ha-1 according to the indicated variables
is summarized in Table 2. The results show that
the variables that had significant differences were type of soil and planting method.
These two variables are significant elements in the rice farms that influenced the
generation of higher quantities of rice straw. Rice farmers can take advantage of
these two factors as they greatly influence the higher tendency of producing rice
straw in higher quantities. These are key drivers for potential postharvest management activities that
can be explored for a circular economy, providing employment opportunities for rice
farmers.
Table 2: Test of Difference on the Mean Rice Straw Biomass
Ha-1 Generated when grouped According to the indicated variables
|
Variable |
Source of Variation |
F value (F) |
P-value (P) |
Decision |
Interpretation |
|
Category of Land Holdings |
2 ha and below |
0.52 |
0.599 |
Accept Ho |
Not Significant |
|
2.1 and above |
|||||
|
Total |
|||||
|
Rice Cultivar |
Inbreed |
1.75 |
0.196 |
Accept Ho |
Not Significant |
|
Hybrid |
|||||
|
Total |
|||||
|
Type of Soil |
Sandy-loamy |
6.48 |
0.005 |
Reject Ho |
Significant |
|
Sandy |
|||||
|
Total |
|||||
|
Planting Method |
Transplanting |
5.01 |
0.033 |
Reject Ho |
Significant |
|
Direct Seeding |
|||||
|
Total |
|||||
|
Quantity of Fertilizer |
6-9 sacks |
0.65 |
0.589 |
Accept Ho |
Not Significant |
|
10 and above |
|||||
|
Total |
|||||
|
Frequency of Fertilizer Application |
2-3 times |
0.04 |
0.989 |
Accept Ho |
Not Significant |
|
4 times and above |
|||||
|
Total |
|||||
|
Source of Irrigation |
NIA |
0.81 |
0.456 |
Accept Ho |
Not Significant |
|
Other sources |
|||||
|
Total |
|||||
|
Frequency of Irrigation |
4-7 times |
2.44 |
0.086 |
Accept Ho |
Not Significant |
|
8 times and above |
|||||
|
Total |
|||||
|
Quantity of Herbicide |
0 - 1 kg |
0.88 |
0.426 |
Accept Ho |
Not Significant |
|
1.01 kg and above |
|||||
|
Total |
|||||
|
Frequency of Herbicide Application |
0-1 times |
0.14 |
0.714 |
Accept Ho |
Not Significant |
|
2-3 times |
|||||
|
Total |
|||||
|
Quantity of Insecticide |
0 - 1 kg |
2.85 |
0.075 |
Accept Ho |
Not Significant |
|
Within Groups |
|||||
|
Total |
|||||
|
Frequency of Insecticide Application |
0-1 times |
2.30 |
0.100 |
Accept Ho |
Not Significant |
|
2-3 times |
|||||
|
Total |
|||||
|
Quantity of Fungicide |
0 kg |
0.97 |
0.424 |
Accept Ho |
Not Significant |
|
- 2 kg |
|||||
|
Total |
|||||
|
Frequency of Fungicide Application |
0 times |
1.42 |
0.258 |
Accept Ho |
Not Significant |
|
1-2 times |
|||||
|
Total |
|||||
|
Quantity of Molluscicide |
0.50 kg |
1.47 |
0.247 |
Accept Ho |
Not Significant |
|
0.51 kg and above |
|||||
|
Total |
|||||
|
Frequency of Molluscicide Application |
1 time |
1.24 |
0.276 |
Accept Ho |
Not Significant |
|
2 times |
|||||
|
Total |
|||||
|
Quantity of Rodenticide |
0 kg |
1.02 |
0.321 |
Accept Ho |
Not Significant |
|
0.1 kg and above |
|||||
|
Total |
|||||
|
Frequency of Rodenticide Application |
0 times |
1.02 |
0.321 |
Accept Ho |
Not Significant |
|
1 time |
|||||
|
Total |
|||||
|
Quantity of Other Pesticides |
0 - 0.5 kg |
0.67 |
0.522 |
Accept Ho |
Not Significant |
|
0.51 kg and above |
|||||
|
Total |
|||||
|
Frequency of Other Pesticides Application |
0 time |
0.63 |
0.538 |
Accept Ho |
Not Significant |
|
1 time |
|||||
|
Total |
|||||
|
Cropping System |
Monocropping |
0.31 |
0.580 |
Accept Ho |
Not Significant |
|
Crop Rotation |
|||||
|
Total |
On the other hand, the various factors did not show a significant
difference in the generation of total straw biomass. These factors included the
category of land holdings, rice cultivar, fertilizer management, water management,
pesticide application, and cropping system. These factors did not significantly
have a substantial impact on the quantity of rice straw generated.
The results showed that the
type of soil had a significant difference on the mean of straw biomass ha-1
generated. Sandy-loamy soil yielded the highest mean straw biomass ha-1 generated,
while the sandy soil had the lowest generation of mean of straw biomass ha-1.
This implies that sandy-loamy soil is the most favorable condition of the soil in
which rice straws are fostered for their growth and development until fully matured.
The sandy-loamy soil is highly suitable for rice nutrient contents of the soil (PhilRice,
2015). The study of Li et al. (2012) revealed that soil is a significant factor
that impacts the high production of agricultural
residue. Additionally, Singh et al. (1995) stated that soil type and fertility result
in variation in generation of straw biomass. Since the type of soil in the study
sites is favorable for rice plants, it might contribute to the generation of a high
mean of total straw biomass. Hence, there is a massive generation of mean total
straw. This suggests that rice farmers seeking to produce higher quantities of rice
straws for postharvest management activities should select the type of soil that
is favorable for rice plants to grow and develop when purchasing rice paddies or
managing their rice field to foster the favorable amount of crop residue yield. On the other hand, due to the characteristics
of sandy soil, the generation of crop residues is lower and requires intensive proper
care and maintenance.
The findings also revealed
that mean straw biomass ha-1 had a significant difference in the method
of planting. This indicates that the planting method impacts the mean straw biomass
generation in ha-1. In application, if rice farmers prefer to produce
higher rice straw for postharvest management activities, they should resort to employing
a transplanting method. Transplanting has a greater mean of straw biomass ha-1
than direct seeding. The significant difference is primarily attributed to its high
yield potential during the dry season, according to (IRRI, 2016). The yield is directly
proportional to rice straw. This means, as the yield increases, the rice straw also
increases. The SGR shows a more than three-fourths ratio of rice paddies and straw,
which is almost a one-to-one ratio. Moreover, Reddy et al. (2003) revealed that
planting methods influenced the quantity of crop residue production. Transplanting
has a higher density of rice plants compared to direct seeding. Transplanting has
a higher number of seedlings planted per hill which promotes higher generation of
crop residues. On the other hand, direct seeding features broadcasting seeds randomly
in the rice field. Consequently, this type of planting method has a lesser density
of rice plants and has a lower generation of mean total straw biomass.
Rice Straw Management Activities of the Rice
Farmers
Postharvest practices are common activities
undertaken by rice farmers after a major cropping season. This activity deals with
how rice farmers process their crop residue, especially the rice straw. Table 3
mentioned the postharvest management practices of rice farmers in Isabela.
According to the results, straw incorporation
is the most widely practiced method, accounting for 54.84% of the respondents, followed
by straw incorporation with crop rotation, consisting of 22.58%. Straw incorporation
and rice ratooning are also practiced with 12.90%, while 3.23% use at least a combination
of the three ways, such as straw incorporation, rice ratooning, straw mushroom production,
or surface retention.
Table 3: The Postharvest Management Practices of Rice Farmers
|
Postharvest Activities |
Percentage (%) |
|
Straw Incorporation |
54.84 |
|
Straw Incorporation + Crop Rotation |
22.58 |
|
Straw Incorporation + Rice Ratooning |
12.90 |
|
Straw Incorporation + Rice Ratooning
+ Straw Mushroom Production |
3.23 |
|
Straw Incorporation + Surface
Retention + Straw Mushroom Production |
3.23 |
|
Straw Incorporation + Rice Ratooning
+ Surface Retention |
3.23 |
|
Total |
100.00 |
Discussion
The
findings of the study are contrary to the results obtained by Singh et al. (2021),
who reported that the most prevalent postharvest practice in the whole world is
RSB, or open-field burning of straw; Mendoza (2015) reported that 76% of the Filipino
rice farmers burn RS, and Gadde, Menke, and
Wassman (2009) said that 95% of the RS are subjected to RSB. The prevalence of RSB
in previous studies is attributed to the use of axial threshers, where rice crop
residues are piled up during threshing. This allows rice farmers to easily burn
RS.Nowadays, the axial threshers are progressively replaced by combine harvesters.
The utilization of this newly introduced farm equipment became popular and brought
convenience to rice farmers (IRRI, 2016). However, the collection of loose rice
straw on the paddy fields has become a challenge. Gummert et al. (2020) suggested
that mechanized collection of rice straw will solve the emerging concerns on loose
rice straw.
However
due to the expensive cost of mechanized collection of rice straw, all of the rice
farmers practiced straw incorporation. The loose and spread rice straw is incorporated
in the soil and is allowed for in-situ natural
decomposition. However, improper in-situ straw incorporation results in a GHG emission
spike from the soil. Ginez and Siladan (2025) revealed that soil emission from rice
cultivation contributed 3,953.79 kg CO2e ha-1. The lack of
knowledge and skills of rice farmers in in-situ straw incorporation contributed
to the generation of high GHG emissions in rice cultivation. On the other hand,
value-added products of rice straw have been introduced to farmers through technical
briefings and orientations. As a result, 9.67% of the rice farmers, though in a
very low adoption, practice surface retention and production of straw mushrooms
as additional means of considering the value of RS. The gradual introduction of
the value-added products of rice straw to the rice farmers would be necessary in
order for them to promote a circular economy of rice straw. A cradle-to-cradle approach
for rice straw could include fodder, a source of energy, the production of
paper, and the production of biochar. This indicates that skills training is needed
for rice farmers to deepen their appreciation and recognition of the value and importance
of rice straw. This will certainly result in alternative means of livelihood, promotion
of health and wellness, and climate change mitigation.
Factors that Influenced the Postharvest Management
Practices among Rice Farmers
The various factors
that influenced the postharvest management practices
among rice farmers include sex, household size, rice production training, farmers
organization (FO), land ownership, machine ownership, road structure, and type of
soil. Table 4, 5, and 6 summarize the test of the relationship between demographic
profile, ownership, and farm characteristics, respectively.
Table 4: Test of Relationship Between Demographic Profile
and Postharvest Management Practices
|
Variable |
Chi-square |
p |
Decision |
Interpretation |
|
Age |
4.37 |
0.112 |
Accept Ho |
Not
significant |
|
Sex |
9.14 |
0.010 |
Reject Ho |
Significant |
|
Household Size |
6.55 |
0.038 |
Reject Ho |
Significant |
|
Number of Household Working in the
Farm |
2.59 |
0.298 |
Accept Ho |
Not
significant |
|
Number of Farming Experience |
0.88 |
0.643 |
Accept Ho |
Not significant |
|
Educational Attainment |
1.91 |
0.385 |
Accept Ho |
Not
significant |
|
Rice Production Training |
5.93 |
0.028 |
Reject Ho |
Significant |
|
Farm Organization |
6.81 |
0.012 |
Reject Ho |
Significant |
|
Source of Income |
0.33 |
0.960 |
Accept Ho |
Not
significant |
|
Household Monthly Income |
3.32 |
0.190 |
Accept Ho |
Not
significant |
Table 5: Test of Relationship Between Ownership and Postharvest
Management Practices
|
Variable |
Chi-square |
df |
p |
Decision |
Interpretation |
|
Land Ownership |
5.93 |
1 |
0.028 |
Reject Ho |
Significant |
|
Machine Ownership |
5.99 |
1 |
0.032 |
Reject Ho |
Significant |
|
Animal Ownership |
3.15 |
1 |
0.146 |
Accept Ho |
Not significant |
Table 6: Test of Relationship Between Farm Characteristics
and Postharvest Management Practices
|
Variable |
Chi-square |
p |
Decision |
Interpretation |
|
Category of Land Holdings |
0.72 |
0.456 |
Accept Ho |
Not significant |
|
Road Structure |
6.90 |
0.032 |
Reject Ho |
Significant |
|
Type of Soil |
6.24 |
0.044 |
Reject Ho |
Significant |
|
Source of Irrigation |
3.78 |
0.151 |
Accept Ho |
Not significant |
|
Water Availability |
3.04 |
0.219 |
Accept Ho |
Not significant |
|
Rice Cultivar |
0.02 |
0.889 |
Accept Ho |
Not significant |
For sex, female household heads tend to
practice crop rotation after the major harvest more than their male counterparts.
This implies that females adopt more economical and more sustainable practices than
male heads. The visibility of women in rice farming is manifested in their higher
adoption of newly introduced technologies and efficient management of resources,
resulting in resource preservation (Tamang, Paudel &
Shreshta, 2014; Takayama, Horibe, & Nakatani, 2018). The technology includes
crop rotation which serves as an alternative source of income prior to the next
cropping season. Through this, women maximize the optimum potential of the resources
which in turn are more economical and more sustainable.
Household size is another variable that
showed significant correlation to the postharvest management practices. The household
size with four or fewer members tends to practice crop rotation after the main crop
while households with five or more members do not. Meanwhile, rice straws are incorporated
in their rice fields either for the next cropping or for planting cash crops. Hence,
the ideal household size contributes to rice farmers' families practicing more economical
and more sustainable rice cultivation practices than the households with more members
through crop rotation.
The results of this study are contrary
to the results of the study of Mukarumbwa et al. (2017).
They reported that household size increases the number of postharvest practices.
This is because more family members are needed in the performance of postharvest
practices. Larger household sizes offer additional labor to rice farmers from tending
the cash crops up to marketing them. The difference in the results is primarily
associated with the farm size, type of crops, and purpose of planting. In the present
study, rice farmers who practice crop rotation planted mung beans or corn using
a small portion of their rice field. They intended to plant vegetables primarily
for personal consumption. In case there was a surplus, they shared or sold it to
their neighbors. Furthermore, for rice farmers who planted corn, they would not
require additional labor because mechanization has replaced human labor from planting
to harvesting. On the other hand, larger households prepared one family member for
the next cropping season that requires intensive human labor.
Rice farmers who attended and received
training in rice production implemented up to three postharvest methods while rice
farmers with no training simply incorporated rice straw in their farm. According
to the Philippine Statistics Authority (PSA, 2021), 19.6 - 28.1% of the rice farmers
said that they received training. Seminars
and training attended by the farmers include but are not limited to the application
of pesticides, seeds, the application of fertilizers, pest control, and mushroom
production. Thus, training provided rice farmers with necessary knowledge and skills
in the value-added products offered by rice residues. Accordingly, rice farmers
tend to integrate postharvest management practices in which they significantly benefit
from it.
Membership in farmers' organizations (FO)
also significantly influenced the adoption of postharvest management practices.
Rice farmers who were members of FOs tended to practice a combination of two to
three postharvest management methods, while non-members primarily practiced straw
incorporation. Membership in FO has a positive influencing power to encourage rice
farmers to implement a variety of postharvest management practices. FO also provides
an avenue for farmers to establish links and networks with other rice farmers. IRRI
(2016) highlighted the importance of FOs to rice farmers because they offer services
for economic and technical efficiency among their members. Indeed, FOs play a critical
role for rice farmers in the economic and technical as well as environmental efficiency.
For land ownership, rice farmers who are
owner-cultivators tend to practice crop rotation while tenants do not. This signifies
the land ownership is directly associated with the rice farmers’ decision to explore
alternative sources of income to increase their technical efficiency and productivity
through crop rotation. Additionally, this practice implies environmental efficiency
because of their intention to maximize the optimum benefits given by the rice straws
in their rice field. Rice straws serve as mulch to retain moisture of the growing
crops and eventually serve as compost and organic fertilizer over time. This certainly
reduces the inputs of commercial and inorganic fertilizer. Bokusheva
et al. (2012) studied the factors on the adoption of postharvest storage and found
out that owner-cultivators adopted postharvest storage facilities. This indicates
that owner-cultivators seek technical productivity by storing their crop residues
and finding value-added products for them such as mulch, organic fertilizer, fodder,
straw mushroom production, thatching, and stover.
Additionally, machine ownership directly
influenced the practice of postharvest management. Rice farmers who own agricultural
machinery have a higher tendency to practice crop rotation, while rice farmers who
do not own agricultural machinery do not practice crop rotation. Though this agricultural
machinery is not directly involved in the postharvest management practices, it influenced
them to practice crop rotation. Agricultural machinery involved in crop rotation
for vegetable crops is intended for land preparation only. Other rice farmers who
practice crop rotation usually rent machinery, especially for land preparation and
harvesting. This implies that it is high time to realize the advantages of postharvest
technologies both for rice production and production technology for crop rotation.
Castro (2004) underscored the significant contribution of postharvest technologies
to the economy of the 90% of smallholder farmers in the country. Given the present
circumstances of rice farmers, postharvest technologies will greatly influence them
to maximize the potential of crop residues. If rice farmers are subsidized with
farm machinery, especially for postharvest technologies, they have a higher probability
of efficiently managing their crop residues. Thereby, their technical productivity
and efficiency can be enhanced as well as their environmental sustainability. Likewise,
governments should adopt projects and services for infrastructures and invest in
agricultural machinery intended for rice farmers.
Meanwhile, farm characteristics such as
road structures and type of soils had significant relationships to the postharvest
management practices. This signifies that these two factors are significant considerations
for rice farmers to employ favorable postharvest management practices in their own
fields. For rice farmers who have earthen road access from their residence to their
rice fields, they commonly employ straw incorporation. Pure earthen roads may contribute
to the difficulty of delivering services such as proper care and maintenance of
crops and products such as yield for rice farmers. Consequently, rice farmers resorted
to simply incorporating crop residues on their own rice farms.
On the other hand, rice farmers who have
fully concrete, and a combination of concrete and earthen road structures leading
to their farm lands tend to practice a combination of two or more postharvest methods.
Rice farmers under these road structures have explored straw incorporation, rice
ratooning, crop rotation, surface retention, and mushroom production. Employing
combinations of these postharvest methods is likely attributed to the accessibility
of roads which provides rice farmers the ability to easily deliver the services
and products to and from their rice fields (IRRI, 2016).
Lastly, the type of soil directly influenced
rice farmers to employ postharvest activities. Rice farmers with sandy-loamy soil
tend to practice two or three combinations of postharvest methods while those with
sandy and loamy soil practice straw incorporation only. The favorable type of soil influences rice farmers
to maximize the various benefits of sandy loam for crop rotation and rice ratooning.
PhilRice (2015) examined the soil series in Isabela, in which they emphasized the
suitable types of soil for lowland rice crops. It was revealed that sandy-loamy
and clay-loamy soils are the highly favorable soils for rice production. Given these
data, rice farmers may take advantage of the economic benefits they derive from
practicing the aforementioned postharvest method based on the type of soil found
in their respective rice fields. The more knowledgeable rice farmers are in their
rice fields, the more they employ sustainable agricultural practices. For the government,
infrastructure for soil analysis should be established; mandatory soil testing should
be done; and training rice farmers to conduct soil analysis will be practiced. Through
these ways, rice farmers are equipped with necessary knowledge and skills for the
said purpose and for environmental efficiency.
Conclusion and recommendations
The mean straw biomass ha-1 generated
by the rice farmers is 5,219.73 kg or 5.2 t. This comprises 65-69% of the total
straw biomass in comparison to the national straw generation. Thus, there is a massive significant contribution
of Isabela, Philippines vis-à-vis the national generation of total straw biomass
in 2020. Relative to the massive contribution of rice straw in Isabela, Philippines,
factors such as type of soil and planting method are proven considerations for the
high generation of total straw biomass. Moreover, sex, household size, rice production training, farm organization,
land ownership, machine ownership, road structure, and type of soil are key determinants
in the determination, selection, and implementation of postharvest management practices
of the rice farmers.
This substantial massive generation of total
straw biomass in Isabela, Philippines, could provide a wide array of benefits, most
especially to the rice farmers. The involved persons could take advantage of the
massive generation of rice straw especially the rice farmers. Political will, partnership
and collaboration, provision of physical infrastructures, and active participation
among rice farmers are main ingredients to the effective management of rice straws.
The political leaders can fully exercise their political will in support of the
sustainable management of rice straw; the Department of Agriculture (DA) and Local
Government Units (LGU) can strengthen and further their partnership and collaboration
with the various national government agencies, private companies and institutions;
the DA and LGUs should invest more in postharvest activities such as facilities
and trainings; and rice farmers are well stimulated with various benefits for them
to guarantee their full cooperation and active engagement.
When all
stakeholders participate in the sustainable management of rice straw, RS will no
longer be considered as agricultural waste (cradle-to-waste) but rather an additional
agricultural wealth (cradle-to-cradle). Consequently, RS can be subjected to its
various potentials leading to a circular economy which in turn contributes to the
productivity, technical efficiency, and environmental efficiency of the community,
especially to the rice farmers.
Based on the foregoing
conclusions, the following recommendations are proposed. For the DA and LGU, it is recommended that:
· They should strengthen and sustain long-term partnerships and collaboration
with other national government agencies, private and public institutions, private
industries, and non-government organizations to promote fresh perspectives and ideas
in rice farming and to maximize shared facilities to cater to the needs, demands,
and requirements of the rice farmers.
· Allocate more funds and invest in the physical infrastructures for
postharvest facilities in managing the rice crop residues. It can help rice farmers
in diverting their RS into a circular economy as an alternative source of livelihood.
· Provide more extensive skills training on postharvest management activities
to all rice farmers in order for them to be more adept and more skillful in managing
their crop residues.
· Devise a scheme for a localized incentivization program to encourage
rice farmers to integrate and implement sustainable rice-farming practices. Incentives
may come in modest forms such as food assistance or financial support for barangay-level
farm input projects such as RS vermi-composting, RS mushroom production, handicrafts
made of RS, etc.
· For farmers, they should actively participate and be involved in any
capacity-building activities conducted by DA and LGU in order to learn, unlearn,
and relearn valuable knowledge, skills, and attitudes in sustainable rice farming
needed in enhancing productivity, increasing technical efficiency, and fostering
environmental efficiency.
References
Allen, J., Pascual, K. S., Romasanta, R. R., Van Trinh, M., Van Thach, T.,
van Hung, N., Sander, B.O., and Chivenge.
P. (2020). Rice straw management effects
on greenhouse gas emissions and mitigation options. Sustainable rice straw management
pp. 145–160). Springer Nature. https://doi.org/10.1007/978-3-030-32373-8_9
Balingbing, C., Van Hung, N., Roxas, A. P.,
Aquino, D., Barbacias, M. G., & Gummert, M. (2020). An assessment on the technical
and economic feasibility of mechanized rice straw collection in the Philippines.
Sustainability, 12(17), 7150. https://doi.org/10.3390/su12177150
Balingit, R. (2012). [Map
of Isabela, Philippines] [Image]. Wikimedia Commons. https://commons.wikimedia.org/wiki/File:Ph_fil_isabela.png
Bhattacharyya, P., &
Padhi, P. P. (2019). Rice straw management: Challenges and opportunity. In Climate
resilient agricultural technologies for future: Training manual. ICAR-National
Rice Research Institute. https://krishi.icar.gov.in/jspui/bitstream/123456789/31842/1/MTC_TM.pdf
Bhattacharyya, P., Bhaduri,
D., Adak, T., Munda, S., Satapathy, B. S., Dash, P. K., Padhi, S. R., & et al.
(2020). Characterization of rice straw from major cultivars for best alternative
industrial uses to cutoff the menace of straw burning. Industrial Crops and Products,
143, 111919.
https://doi.org/10.1016/j.indcrop.2019.111919
Bimbraw, A. S. (2019). Generation
and impact of crop residue and its management. Current Agriculture Research Journal,
7(3), 304–309. https://doi.org/10.12944/CARJ.7.3.05
Bokusheva, R., Finger, R., Fischler, M., Berlin,
R., Marín, Y., Pérez, F., & Paiz, F. (2012). Factors determining the adoption
and impact of a postharvest storage technology. Food Security, 4(2), 279–293.
https://doi.org/10.1007/s12571-012-0184-1
Castro, S. G. (2004). Post-harvest technology
in the Philippines. Semantic Scholar.
Climate Transparency. (2021).
Philippines: Country profile 2020. https://www.climate-transparency.org/media/philippines-country-profile-2020
Domínguez‐Escribá, L., &
Porcar, M. (2010). Rice straw management: The big waste. Biofuels, Bioproducts
and Biorefining, 4(2), 154–159. https://doi.org/10.1002/bbb.196
Gadde, B., Menke, C., & Wassmann, R. (2009).
Rice straw as a renewable energy source in India, Thailand, and the Philippines:
Overall potential and limitations for energy contribution and greenhouse gas mitigation.
Biomass and Bioenergy, 33(11), 1532–1546. https://doi.org/10.1016/j.biombioe.2009.08.001
Ginez, J. C., & Siladan, M. (2025). Carbon footprint assessment of rice
cultivation of select rice farmers in Isabela, Philippines: A case study. International
Journal of Agronomy and Agricultural Research, 26(5), 42–54. https://innspub.net/carbon-footprint-assessment-of-rice-cultivation-of-select-rice-farmers-in-isabela-philippines-a-case-study/
Global Climate Change. (2016).
Greenhouse gas emissions factsheet: Philippines. USAID. https://www.climatelinks.org/resources/greenhouse-gas-emissions-factsheet-philippines
Gummert, M., Van Hung, N., Chivenge, P., &
Douthwaite, B. (Eds.). (2020). Sustainable rice straw management. Springer
Nature. https://doi.org/10.1007/978-3-030-32373-8
International Rice Research
Institute. (2016). Can PH rice compete globally? What can PH do? Philippine
Rice Research Institute. https://www.philrice.gov.ph/download/can-ph-rice-compete-globally-what-can-ph-do/
Kaur, D., Bhardwaj, N. K.,
& Lohchab, R. K. (2017). Prospects of rice straw as a raw material for paper
making. Waste Management, 60, 127–139. https://doi.org/10.1016/j.wasman.2016.08.001
Li, X., Mupondwa, E., Panigrahi,
S., Tabil, L., Sokhansanj, S., & Stumborg, M. (2012). A review of agricultural
crop residue supply in Canada for cellulosic ethanol production. Renewable and
Sustainable Energy Reviews, 16(5), 2954–2965. https://doi.org/10.1016/j.rser.2012.02.013
Mandal, K. G., Misra, A.
K., Hati, K. M., Bandyopadhyay, K. K., Ghosh, P. K., & Mohanty, M. (2004). Rice
residue-management options and effects on soil properties and crop productivity.
Journal of Food Agriculture and Environment, 2(1), 224–231. https://www.researchgate.net/publication/272073156_Rice_residue-_management_options_and_effects_on_soil_properties_and_crop_productivity
Maneepitak, S., Ullah, H.,
Paothong, K., Kachenchart, B., Datta, A., & Shrestha, R. P. (2019). Effect of
water and rice straw management practices on yield and water productivity of irrigated
lowland rice in the Central Plain of Thailand. Agricultural Water Management,
211, 89–97.https://doi.org/10.1016/j.agwat.2018.09.041
Mendoza, T. C. (2015). Enhancing
crop residues recycling in the Philippine landscape. In S. S. Muthu (Ed.), Environmental
implications of recycling and recycled products (pp. 79–100). Springer. https://doi.org/10.1007/978-981-287-643-0_4
Mukarumbwa, P., Mushunje,
A., Taruvinga, A., Akinyemi, B., & Ngarava, S. (2017). Factors influencing number
of post-harvest practices adopted by smallholder vegetable farmers in Mashonaland
East Province of Zimbabwe. International Journal of Development and Sustainability,
6(10), 1774–1790. https://www.academia.edu/71639464/Factors_influencing_number_of_post_harvest_practices_adopted_by_smallholder_vegetable_farmers_in_Mashonaland_East_Province_of_Zimbabwe
Nguyen, V. H., Maguyon-Detras,
M. C., Migo, M. V., Quilloy, R., Balingbing, C., Chivenge, P., & Gummert, M.
(2020). Rice straw overview: Availability, properties, and management practices.
In M. Gummert, N. Van Hung, P. Chivenge, & B. Douthwaite (Eds.), Sustainable
rice straw management (pp. 1–13). Springer Nature. https://doi.org/10.1007/978-3-030-32373-8_1
Nguyen, V. H., Topno, S., Balingbing, C., Nguyen,
V. C. N., Röder, M., Quilty, J., Jamieson, C., Thornley, P., & Gummert, M. (2016).
Generating a positive energy balance from using rice straw for anaerobic digestion.
Energy Reports, 2, 117–122. https://doi.org/10.1016/j.egyr.2016.05.005
Philippine Rice Research Institute. (2015).
Simplified keys to soil series for Isabela. https://www.philrice.gov.ph/wp-content/uploads/2015/08/Simplified-Keys-to-Soil-Series-Isabela.pdf
Philippine Statistics Authority.
(2021). *Palay production in the Philippines, 2018-2020*. https://psa.gov.ph/sites/default/files/Palay%20Production%20in%20the%20Philippines%2C%202018-2020.pdf
Reddy, B. V. S., Sanjana
Reddy, P., Bidinger, F., & Blümmel, M. (2003). Crop management factors influencing
yield and quality of crop residues. Field Crops Research, 84(1–2), 57–77.
https://doi.org/10.1016/S0378-4290(03)00141-2
Romasanta, R. R., Sander,
B. O., Gaihre, Y. K., Alberto, M. C., Gummert, M., Quilty, J., Nguyen, V. H., &
et al. (2017). How does burning of rice straw affect CH4 and N2O emissions? A comparative
experiment of different on-field straw management practices. Agriculture, Ecosystems
& Environment, 239, 143–153. https://doi.org/10.1016/j.agee.2016.12.042
Sheikh, G. G., Ganai, A.
M., Reshi, P. A., Bilal, S., Mir, S., & Masood, D. (2018). Improved paddy straw
as ruminant feed: A review. Agricultural Reviews, 39(2), 137–143. https://doi.org/10.18805/ag.R-1667
Singh, R. B., Sana, R. C.,
Singh, M., Chandra, D., Shukla, S. G., Walli, T. K., Pradhan, P. K., & Kessels,
H. P. P. (1995). Rice straw-its production and utilization in India. In Proceedings
of the International Seminar on Recent Advances in Ruminant Nutrition (pp. 325–345).
https://edepot.wur.nl/333859
Swain, M. R., Singh, A.,
Sharma, A. K., & Tuli, D. K. (2019). Bioethanol production from rice-and wheat
straw: An overview. In R. C. Ray & S. Ramachandran (Eds.), Bioethanol production
from food crops (pp. 213–231). Academic Press. https://doi.org/10.1016/B978-0-12-813766-6.00011-4
Takayama, T., Horibe, A.,
& Nakatani, T. (2018). Women and farmland preservation: The impact of women’s
participation in farmland management governance in Japan. Land Use Policy, 77,
116–125. https://doi.org/10.1016/j.landusepol.2018.05.033
Tamang, S., Paudel, K. P., & Shrestha,
K. K. (2014). Feminization of agriculture and its implications for food security
in rural Nepal. Journal of Forest and Livelihood, 12(1), 20–32. https://enliftnepal.org/wp-content/uploads/2019/01/09_JP_2014_Tamang-et-al_Feminisation-of-Agriculture-in-Rural-Nepal.pdf
United States Environmental Protection Agency.
(2020). Global greenhouse gas emissions data. https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data
Wikipedia. (2024). Knowledge. In Wikipedia.
https://en.wikipedia.org/wiki/Knowledge