*Corresponding Author: Ambili T.R, PG and Research Department of Zoology, Alphonsa
College Pala, Kottayam-686574, Kerala, India Email: [email protected]. 34
International Journal of Zoology and Applied Biosciences ISSN: 2455-9571
Volume 10, Issue 5, pp: 34-44, 2025 http://www.ijzab.com
https://doi.org/10.55126/ijzab.2025.v10.i05.005
Research Article
A STUDY ON ENHANCING SOIL MOISTURE RETENTION THROUGH THE
APPLICATION OF BIODEGRADABLE HYDROGELS
1Sherin C Baby, 1*Ambili T.R, 2Elezabeth Basil, 3Sojomon Mathew, 4Shiny K.J
1PG and Research Department of Zoology, Alphonsa College Pala, Kottayam-686574, Kerala, India
2Department of Zoology, Bishop Chulaparambil Memorial College, Kottayam-686001, Kerala, India
3 Department of Zoology, Government College, Kottayam-686013, Kerala, India.
Article History: Received 22nd July 2025; Accepted 27th August 2025; Published 30th September 2025
ABSTRACT
Biodegradable hydrogels have emerged as a promising solution in the realm of sustainable agriculture, offering innovative
approaches to address the pressing challenges faced by the industry. A simple, low-cost formulation that could be prepared
without any sophisticated techniques would be helpful to the farmers in creating a biodegradable hydrogel of their own. In
the current study, three distinct biopolymer-based hydrogels were prepared by the chemical polymerization technique.
They are agar hydrogel, hydroxyethyl cellulose (HEC) hydrogel, and a composite hydrogel made from a 50:50
combination of agar and hydroxyethyl cellulose. The present study found that the HEC hydrogel has a maximum water
absorbency of 50.76%. The loamy sand soil has a natural capacity to hold soil moisture due to the presence of 3% clay.
This was further increased when the hydrogels were applied. Regardless of the hydrogel utilized, the sandy soil showed a
considerable decline in water retention on the fourth day of the trial. The reduced root volume shows the effectiveness of
HEC hydrogels in retaining soil moisture, thereby preventing roots from penetrating deep into the soil in search of water.
Seedlings cultivated in soil containing HEC hydrogels in loamy sand and sandy soil have longer roots irrespective of the
presence of hydrogel. According to a correlation analysis, there is a strong positive association between the percentage of
soil moisture and the weight percentage of hydrogel degradation. Thus, the gradual deterioration of the hydrogels leads to
the release of moisture into the soil.
Keywords: Biodegradable hydrogels, Hydroxyethyl cellulose, Agar, Soil moisture, Water retention.
INTRODUCTION
Water availability for irrigation has declined in the 21st
century due to increased economic activity and population
growth in arid and semi-arid regions. Climate change has
worsened this issue, causing more frequent droughts and
water shortages, particularly affecting regions like India,
the Middle East, and Sub-Saharan Africa. A global survey
warns that India may face severe water scarcity by 2025,
highlighting the urgent need for solutions.
Agriculture has been significantly impacted by climate
change, especially due to prolonged droughts and rising
temperatures. Efficient water use and minimizing losses
from drainage and evaporation are essential goals in soil
water management (Zhou et al., 2020). Traditional surface
irrigation methods are inefficient, as nearly half the water is
lost to evaporation and runoff. While modern methods like
drip and sprinkler systems reduce water waste, high costs,
limited support, and equipment issues deter widespread
adoption. Most of the world’s 120 million farms are small-
scale, and low profits make investment in advanced
irrigation technologies unfeasible (Karnani, 2017).
In recent years, superabsorbent polymers (SAPs) have
gained attention for agricultural use due to their ability to
retain water and support plant growth under drought stress
(Cheng et al., 2018). Hydrogels, which have a three-
dimensional polymer network that holds large amounts of
water, are widely used in agriculture to improve soil
quality, seed germination, and crop survival in dry regions
(Bashir et al., 2020; Kabir et al., 2018). The first water-
absorbing polymer was developed in 1938, followed by
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 35
hydrogels in the 1950s, initially used in ophthalmology.
Commercial SAP production began in the 1970s, with wide
applications in Japan, France, and Germany. By 1990,
global production surpassed one million tons (Zohuriaan &
Kabiri, 2008).
Hydrogels are classified based on their charge, sensitivity,
crosslinking method, and polymer source. They can be
made from natural, synthetic, or blended polymers and
formed via various methods such as chemical or physical
crosslinking, UV irradiation, and bulk polymerization.
They are also categorized as neutral, anionic, or cationic
based on the polymer’s charge (Bashir et al., 2020). Most
commercial hydrogels use acrylic acid and acrylamide,
which are expensive and potentially harmful. Many are
non-biodegradable and may release toxic residues like
acrylamide, a known carcinogen. Consequently, researchers
are focusing on creating eco-friendly, biodegradable
hydrogels from safer, plant-based materials (Slutz, 2023).
Biopolymer-based hydrogels offer several benefits:
biodegradability, biocompatibility, low cost, renewability,
and safety. Their decomposition can even enrich the soil
with nutrients.This project involves the development of
three biopolymer-based hydrogels. One uses agar powder
derived from seaweed, another uses hydroxyethyl cellulose
(HEC) from plant cell walls, and the third combines both.
All formulations include citric acid, which helps form a
water-retentive network by creating a mildly acidic
environment through cationic polymerization. These
hydrogels act as water reservoirs near plant roots. When
mixed with soil, they can improve permeability,
germination rates, and microbial activity, enhance plant
growth and yield even in poor soil or drought-prone
conditions. By reducing drought stress and oxidative
damage, hydrogels offer a promising solution for
sustainable agriculture in challenging climates (Karnani,
2017). A low-cost, easy-to-make biodegradable hydrogel
could help farmers protect crops from climate change
without needing advanced tools. It would also benefit urban
gardeners by reducing irrigation frequency. Introducing
hydrogels into agriculture supports sustainable farming.
India’s agricultural potential is underused, even as global
food demand rises. Embracing tech-driven farming can
bring environmental and economic gains. By improving
soil moisture retention, hydrogels could help reclaim arid
and desert lands once considered unfarmable.
MATERIALS AND METHODS
Materials and Equipment
Agar powder(60 g), Hydroxyethyl cellulose (HEC) powder
(60 g),Citric acid, (30g),Weighing machine, Water, Kettle
or device for boiling, 4-cup (1-liter) measuring cup,3
containers for storing each type of hydrogel, Containers or
bowls that can hold at least 1 liter of water (9),Two types
of potting soil (loamy sand soil and sandy soil)
preferably without vermiculite or perlite (water-holding
agents); enough to fill up to 60 pots, 2.00 micron mesh,
Small pots, 500mL Graduated cylinder, Seeds of Vigna
angularis, Paper towel, Ruler, Oven, Lab notebook.
Trial conditions
The experiment was conducted from April 25, 2024 to
May 30, 2024 at Alphonsa College Pala (9° 42' 12" N 76°
40' 1" E) with an average temperature of 27 ° C.
Preparation of hydrogels
Three 500 mL biodegradable hydrogels were prepared. For
the agar hydrogel, 40 g of agar and 10 g of citric acid were
mixed in a heat-resistant cup with 500 mL of boiling water,
stirred until smooth, and then poured into a labeled
container to cool for at least 3 hours before testing. HEC
and 50:50 agar-HEC composite hydrogels were prepared
similarly.
Procedure for testing water absorption capacity of each
hydrogel
Each empty container was weighed, then a large piece of
hydrogel was added, and its dry weight (W0) was recorded
along with the total weight. Water was added to fully
submerge the hydrogels. After one hour, the saturated
samples were removed, surface water was filtered off, and
the swollen weight (W1) was measured. The water
absorption capacity (W.A.C, g⋅g-1) was calculated using the
equation:
Water Absorption Capacity, W.A.C(g.g-1 ) = (W1-Wo)/ Wo
Where,
Wo denotes the dry weight of the hydrogel
W1 is the weight of swollen hydrogel samples
The water absorption capacities of reported results
were averages of 3 measured values. (Vo et al.,
2022).
Determining soil texture
Soil samples were collected from two sites in Idukki
district: sandy soil from the Thodupuzhayar River bank
(9°47'20.0"N, 76°50'51.9"E) and loamy sand from a field in
Purapuzha panchayat (9°50'56.6"N, 76°37'51.8"E),
avoiding areas likely to contain vermiculite or perlite. Both
samples were sieved through a 2.00-micron mesh to
remove debris. Soil texture was analyzed microscopically
by measuring the Feret diameter of 100 particles. Texture
classification followed the World Reference Base for Soil
Resources (4th ed., 2022). The soils were identified as
loamy sand (82% sand, 15% silt, 3% clay) and sandy soil
(99% sand, 1% silt).
Effects of hydrogel on the moisture retention in soil with
and without hydrogels
This test aimed to assess how hydrogel amendment affects
moisture retention in sandy and loamy sand soils. Soil
samples were dried at 45°C until reaching a constant
weight. A mixture of 25 g dried hydrogel and 75 g dried
www.ijzab.com 35
hydrogels in the 1950s, initially used in ophthalmology.
Commercial SAP production began in the 1970s, with wide
applications in Japan, France, and Germany. By 1990,
global production surpassed one million tons (Zohuriaan &
Kabiri, 2008).
Hydrogels are classified based on their charge, sensitivity,
crosslinking method, and polymer source. They can be
made from natural, synthetic, or blended polymers and
formed via various methods such as chemical or physical
crosslinking, UV irradiation, and bulk polymerization.
They are also categorized as neutral, anionic, or cationic
based on the polymer’s charge (Bashir et al., 2020). Most
commercial hydrogels use acrylic acid and acrylamide,
which are expensive and potentially harmful. Many are
non-biodegradable and may release toxic residues like
acrylamide, a known carcinogen. Consequently, researchers
are focusing on creating eco-friendly, biodegradable
hydrogels from safer, plant-based materials (Slutz, 2023).
Biopolymer-based hydrogels offer several benefits:
biodegradability, biocompatibility, low cost, renewability,
and safety. Their decomposition can even enrich the soil
with nutrients.This project involves the development of
three biopolymer-based hydrogels. One uses agar powder
derived from seaweed, another uses hydroxyethyl cellulose
(HEC) from plant cell walls, and the third combines both.
All formulations include citric acid, which helps form a
water-retentive network by creating a mildly acidic
environment through cationic polymerization. These
hydrogels act as water reservoirs near plant roots. When
mixed with soil, they can improve permeability,
germination rates, and microbial activity, enhance plant
growth and yield even in poor soil or drought-prone
conditions. By reducing drought stress and oxidative
damage, hydrogels offer a promising solution for
sustainable agriculture in challenging climates (Karnani,
2017). A low-cost, easy-to-make biodegradable hydrogel
could help farmers protect crops from climate change
without needing advanced tools. It would also benefit urban
gardeners by reducing irrigation frequency. Introducing
hydrogels into agriculture supports sustainable farming.
India’s agricultural potential is underused, even as global
food demand rises. Embracing tech-driven farming can
bring environmental and economic gains. By improving
soil moisture retention, hydrogels could help reclaim arid
and desert lands once considered unfarmable.
MATERIALS AND METHODS
Materials and Equipment
Agar powder(60 g), Hydroxyethyl cellulose (HEC) powder
(60 g),Citric acid, (30g),Weighing machine, Water, Kettle
or device for boiling, 4-cup (1-liter) measuring cup,3
containers for storing each type of hydrogel, Containers or
bowls that can hold at least 1 liter of water (9),Two types
of potting soil (loamy sand soil and sandy soil)
preferably without vermiculite or perlite (water-holding
agents); enough to fill up to 60 pots, 2.00 micron mesh,
Small pots, 500mL Graduated cylinder, Seeds of Vigna
angularis, Paper towel, Ruler, Oven, Lab notebook.
Trial conditions
The experiment was conducted from April 25, 2024 to
May 30, 2024 at Alphonsa College Pala (9° 42' 12" N 76°
40' 1" E) with an average temperature of 27 ° C.
Preparation of hydrogels
Three 500 mL biodegradable hydrogels were prepared. For
the agar hydrogel, 40 g of agar and 10 g of citric acid were
mixed in a heat-resistant cup with 500 mL of boiling water,
stirred until smooth, and then poured into a labeled
container to cool for at least 3 hours before testing. HEC
and 50:50 agar-HEC composite hydrogels were prepared
similarly.
Procedure for testing water absorption capacity of each
hydrogel
Each empty container was weighed, then a large piece of
hydrogel was added, and its dry weight (W0) was recorded
along with the total weight. Water was added to fully
submerge the hydrogels. After one hour, the saturated
samples were removed, surface water was filtered off, and
the swollen weight (W1) was measured. The water
absorption capacity (W.A.C, g⋅g-1) was calculated using the
equation:
Water Absorption Capacity, W.A.C(g.g-1 ) = (W1-Wo)/ Wo
Where,
Wo denotes the dry weight of the hydrogel
W1 is the weight of swollen hydrogel samples
The water absorption capacities of reported results
were averages of 3 measured values. (Vo et al.,
2022).
Determining soil texture
Soil samples were collected from two sites in Idukki
district: sandy soil from the Thodupuzhayar River bank
(9°47'20.0"N, 76°50'51.9"E) and loamy sand from a field in
Purapuzha panchayat (9°50'56.6"N, 76°37'51.8"E),
avoiding areas likely to contain vermiculite or perlite. Both
samples were sieved through a 2.00-micron mesh to
remove debris. Soil texture was analyzed microscopically
by measuring the Feret diameter of 100 particles. Texture
classification followed the World Reference Base for Soil
Resources (4th ed., 2022). The soils were identified as
loamy sand (82% sand, 15% silt, 3% clay) and sandy soil
(99% sand, 1% silt).
Effects of hydrogel on the moisture retention in soil with
and without hydrogels
This test aimed to assess how hydrogel amendment affects
moisture retention in sandy and loamy sand soils. Soil
samples were dried at 45°C until reaching a constant
weight. A mixture of 25 g dried hydrogel and 75 g dried
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 36
soil was placed in plastic pots, with untreated soil serving
as the control. Each pot was weighed, then 50 mL of
distilled water was added and the weight was recorded
again. Daily weight measurements were taken until no
further weight loss was detected.
Water Retention was evaluated using the formula:
Water Retention, WR (%) =(Wt-W)/ Wi-W ×100
Where,
W is the weight of the sample without water,
Wi is the weight of the sample after adding the water and
Wt refers to the weight of the sample after specified time
intervals.
Water content in the soil, monitored at 26˚C for 20 days
following the first irrigation, was recorded. The experiment
was conducted on both loamy sand and sandy soil with
three trials to obtain accurate and repeatable data.
Calculating the average root volume by displacement
method
Each pot contained 120 g of either sandy or loamy sand soil
mixed with 40 g of hydrogel (3:1 ratio). Control pots had
soil only. Four Vigna angularis seeds were sown 1 cm
below the surface, and 50 ml of water was added. After 14
days of growth, roots were separated, washed, and placed
in 50 ml of water in a 100ml cylinder. The volume
displaced was measured in cm³ per pot (1 cm³ = 1 ml).
Determining the root length at day 14 in Loamy
sand and Sandy soil with and without hydrogel
For each trial, 120 g of soil was mixed with the respective
hydrogel and placed in a pot, with four Vigna angularis
seeds sown 1 cm below the surface. After adding 50 mL of
water to saturate the soil, the plants were cultivated for 14
days. On day 14, seedlings were gently washed with tap
water, dried with paper towels, and root lengths were
measured. Each treatment was replicated three times using
both sandy and loamy sand soils to ensure accuracy.
Biodegradation of hydrogels using soil burial
method
Soil burial is a standardized method used to assess
hydrogel degradation by burying the material in soil and
evaluating weight loss over time. The result is expressed as
a degradation percentage for a predetermined time of 12
days. In this experiment, plastic pots were filled to 80%
capacity with soil, and 10 g of hydrogel was buried 5 cm
below the surface. On the first day, 20 ml of water was
added. Hydrogels were retrieved on days 4, 8, and 12,
washed with distilled water, dried in an oven to constant
weight, and reburied after weighing. On days 4 and 8, 10
ml of water was added.
Degradation (%) = (Wo -Wt)/ Wo × 100
Where,
Wo is the initial weight of the before degradation
Wt are the weights of the hydrogel at
specific time intervals after the beginning of
degradation
Statistical analysis
Data Analysis One-way analysis of variance (ANOVA), t-
Test: Paired Two Sample for Means and correlation
analysis were conducted using Microsoft Excel software
(15.0.4420.1017). The statistical difference was considered
significant if p < 0.05.
RESULTS AND DISCUSSION
The current study created three different types of
biodegradable hydrogels. To ensure repeatable and accurate
results, all experiments were subjected to three trials under
the same environmental conditions. The experiments took
place at 28˚C room temperature for 30 days, beginning
April 25, 2024 and ending May 30, 2024. The study area is
situated at 9° 5056.6 N and 76° 3751.8 E. Water absorption
capacity is a significant measure that determines the
effectiveness of the hydrogel in taking up the available
excess amount of water. Thus, it is significant in evaluating
a hydrogel for its potential application in agriculture.
Table 1. Relative percentage of water absorbed by each hydrogel.
Type of hydrogel Relative% water absorbed
Agar 12.39%
Hydroxyethyl cellulose (hec) 50.76%
Composite hydrogel (agar + hec) 36.85%
Results obtained on the average relative percentage of water absorbed for each type of hydrogel are plotted on a pie
chart.
www.ijzab.com 36
soil was placed in plastic pots, with untreated soil serving
as the control. Each pot was weighed, then 50 mL of
distilled water was added and the weight was recorded
again. Daily weight measurements were taken until no
further weight loss was detected.
Water Retention was evaluated using the formula:
Water Retention, WR (%) =(Wt-W)/ Wi-W ×100
Where,
W is the weight of the sample without water,
Wi is the weight of the sample after adding the water and
Wt refers to the weight of the sample after specified time
intervals.
Water content in the soil, monitored at 26˚C for 20 days
following the first irrigation, was recorded. The experiment
was conducted on both loamy sand and sandy soil with
three trials to obtain accurate and repeatable data.
Calculating the average root volume by displacement
method
Each pot contained 120 g of either sandy or loamy sand soil
mixed with 40 g of hydrogel (3:1 ratio). Control pots had
soil only. Four Vigna angularis seeds were sown 1 cm
below the surface, and 50 ml of water was added. After 14
days of growth, roots were separated, washed, and placed
in 50 ml of water in a 100ml cylinder. The volume
displaced was measured in cm³ per pot (1 cm³ = 1 ml).
Determining the root length at day 14 in Loamy
sand and Sandy soil with and without hydrogel
For each trial, 120 g of soil was mixed with the respective
hydrogel and placed in a pot, with four Vigna angularis
seeds sown 1 cm below the surface. After adding 50 mL of
water to saturate the soil, the plants were cultivated for 14
days. On day 14, seedlings were gently washed with tap
water, dried with paper towels, and root lengths were
measured. Each treatment was replicated three times using
both sandy and loamy sand soils to ensure accuracy.
Biodegradation of hydrogels using soil burial
method
Soil burial is a standardized method used to assess
hydrogel degradation by burying the material in soil and
evaluating weight loss over time. The result is expressed as
a degradation percentage for a predetermined time of 12
days. In this experiment, plastic pots were filled to 80%
capacity with soil, and 10 g of hydrogel was buried 5 cm
below the surface. On the first day, 20 ml of water was
added. Hydrogels were retrieved on days 4, 8, and 12,
washed with distilled water, dried in an oven to constant
weight, and reburied after weighing. On days 4 and 8, 10
ml of water was added.
Degradation (%) = (Wo -Wt)/ Wo × 100
Where,
Wo is the initial weight of the before degradation
Wt are the weights of the hydrogel at
specific time intervals after the beginning of
degradation
Statistical analysis
Data Analysis One-way analysis of variance (ANOVA), t-
Test: Paired Two Sample for Means and correlation
analysis were conducted using Microsoft Excel software
(15.0.4420.1017). The statistical difference was considered
significant if p < 0.05.
RESULTS AND DISCUSSION
The current study created three different types of
biodegradable hydrogels. To ensure repeatable and accurate
results, all experiments were subjected to three trials under
the same environmental conditions. The experiments took
place at 28˚C room temperature for 30 days, beginning
April 25, 2024 and ending May 30, 2024. The study area is
situated at 9° 5056.6 N and 76° 3751.8 E. Water absorption
capacity is a significant measure that determines the
effectiveness of the hydrogel in taking up the available
excess amount of water. Thus, it is significant in evaluating
a hydrogel for its potential application in agriculture.
Table 1. Relative percentage of water absorbed by each hydrogel.
Type of hydrogel Relative% water absorbed
Agar 12.39%
Hydroxyethyl cellulose (hec) 50.76%
Composite hydrogel (agar + hec) 36.85%
Results obtained on the average relative percentage of water absorbed for each type of hydrogel are plotted on a pie
chart.
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 37
Figure 1. Graphical representation of relative percentage of water absorbed by each hydrogel
Hydrogel derived from the chemical polymerization of
Hydroxyethyl cellulose (HEC) offers the maximum water
absorbency (50.76%). As Hydroxyethyl cellulose contains
numerous hydroxyl groups, it increases the hydrophilic
nature of the hydrogel, resulting in a faster rate of water
absorption. Thus the HEC hydrogel is found to be more
effective in absorbing water which would be helpful to
increase the soil moisture after a short rainfall or irrigation
at the times of drought. Capacity for water retention in soil
is important for understanding the potential of hydrogel as
a soil conditioner. The water content in the soil, monitored
over several days following the first irrigation, was
significantly affected by the presence of the hydrogel.
Loamy soil is a mixture of clay, sand, and silt, which
consists of additional organic matter and is very fertile
compared to other types of soil. It is well suited for
cultivation as the plant roots get sufficient amounts of
water and nutrients for their growth and development. This
experiment attempts to evaluate whether the application of
hydrogel can further increase soil moisture.
Table 2. Percentage of water retention in loamy sand soil amended with and without hydrogels.
Days Type of hydrogel
Agar Composite HEC Control
Day 0 100.00 100.00 100.00 100.00
Day 4 70.63 77.11 80.00 71.74
Day 8 48.45 58.67 63.95 50.00
Day 12 25.29 36.23 47.09 31.09
Day 16 22.29 31.73 41.29 26.19
Day 20 2.59 6.33 9.09 3.19
Figure 2. Water retention capacity (%) of pure loamy sand soil (Control) and soil containing the hydrogels Agar,
Composite and HEC.
The graph in Figure 3.2 shows a continuous decrease in
water retention capacity in soil and loss of water over the
course of 20 days. The soil samples containing hydrogel
possessed substantially more humidity, which confirms
their capacity for water uptake. The soil containing HEC
hydrogel had a greater amount of water retention than pure
www.ijzab.com 37
Figure 1. Graphical representation of relative percentage of water absorbed by each hydrogel
Hydrogel derived from the chemical polymerization of
Hydroxyethyl cellulose (HEC) offers the maximum water
absorbency (50.76%). As Hydroxyethyl cellulose contains
numerous hydroxyl groups, it increases the hydrophilic
nature of the hydrogel, resulting in a faster rate of water
absorption. Thus the HEC hydrogel is found to be more
effective in absorbing water which would be helpful to
increase the soil moisture after a short rainfall or irrigation
at the times of drought. Capacity for water retention in soil
is important for understanding the potential of hydrogel as
a soil conditioner. The water content in the soil, monitored
over several days following the first irrigation, was
significantly affected by the presence of the hydrogel.
Loamy soil is a mixture of clay, sand, and silt, which
consists of additional organic matter and is very fertile
compared to other types of soil. It is well suited for
cultivation as the plant roots get sufficient amounts of
water and nutrients for their growth and development. This
experiment attempts to evaluate whether the application of
hydrogel can further increase soil moisture.
Table 2. Percentage of water retention in loamy sand soil amended with and without hydrogels.
Days Type of hydrogel
Agar Composite HEC Control
Day 0 100.00 100.00 100.00 100.00
Day 4 70.63 77.11 80.00 71.74
Day 8 48.45 58.67 63.95 50.00
Day 12 25.29 36.23 47.09 31.09
Day 16 22.29 31.73 41.29 26.19
Day 20 2.59 6.33 9.09 3.19
Figure 2. Water retention capacity (%) of pure loamy sand soil (Control) and soil containing the hydrogels Agar,
Composite and HEC.
The graph in Figure 3.2 shows a continuous decrease in
water retention capacity in soil and loss of water over the
course of 20 days. The soil samples containing hydrogel
possessed substantially more humidity, which confirms
their capacity for water uptake. The soil containing HEC
hydrogel had a greater amount of water retention than pure
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 38
soil, which served as the control. As the soil's humidity
reduced, it gradually released the water it had absorbed by
diffusion. Consequently, agricultural land with soil
containing the hydrogel could possess more moisture
during periods of subsequent dryness since water absorbed
during irrigation and rain would be gradually released from
the added hydrogels.
Table 3. ANOVA Single factor analysis for water retention in loamy sand soil amended with hydrogels at level of
significance, ∝=0.05%.
ANOVA
Source of
Variation
SS Df MS F P-value F crit
Between Groups 23026.72 5 4605.344 116.9118 4.49E-13 2.772853
Within Groups 709.0488 18 39.3916
Total 23735.77 23
The calculated value of F (116.91) is numerically greater
than the table value of F (2.77). Thus, the null hypothesis is
rejected and the alternative hypothesis is accepted i.e., the
three hydrogels differ significantly in their water retention
capacity in loamy sand soil. Sandy soils are those that are
generally coarse-textured until 50 cm deep and
consequently retain few nutrients and have a low water-
holding capacity. Thus, they are known as the poorest type
of soil for agriculture and growing plants. As a result,
modifying such soil is critical for making areas with sandy
soil agriculturally viable.
Table 3. Percentage of water retention in sandy soil amended with and without hydrogels.
Day
TYPE OF HYDROGEL
Agar Composite HEC Control
Day 0 100.00 100.00 100.00 100.00
Day 4 60.87 64.34 67.03 59.32
Day 8 40.24 43.66 45.05 37.77
Day 12 26.45 32.23 38.55 20.69
Day 16 8.67 11.24 14.78 4.78
Day 20 2.59 6.74 9.98 0.84
Figure 3. Water retention capacity (%) of pure sandy soil (Control) and soil containing the hydrogels Agar, Composite and
HEC.
www.ijzab.com 38
soil, which served as the control. As the soil's humidity
reduced, it gradually released the water it had absorbed by
diffusion. Consequently, agricultural land with soil
containing the hydrogel could possess more moisture
during periods of subsequent dryness since water absorbed
during irrigation and rain would be gradually released from
the added hydrogels.
Table 3. ANOVA Single factor analysis for water retention in loamy sand soil amended with hydrogels at level of
significance, ∝=0.05%.
ANOVA
Source of
Variation
SS Df MS F P-value F crit
Between Groups 23026.72 5 4605.344 116.9118 4.49E-13 2.772853
Within Groups 709.0488 18 39.3916
Total 23735.77 23
The calculated value of F (116.91) is numerically greater
than the table value of F (2.77). Thus, the null hypothesis is
rejected and the alternative hypothesis is accepted i.e., the
three hydrogels differ significantly in their water retention
capacity in loamy sand soil. Sandy soils are those that are
generally coarse-textured until 50 cm deep and
consequently retain few nutrients and have a low water-
holding capacity. Thus, they are known as the poorest type
of soil for agriculture and growing plants. As a result,
modifying such soil is critical for making areas with sandy
soil agriculturally viable.
Table 3. Percentage of water retention in sandy soil amended with and without hydrogels.
Day
TYPE OF HYDROGEL
Agar Composite HEC Control
Day 0 100.00 100.00 100.00 100.00
Day 4 60.87 64.34 67.03 59.32
Day 8 40.24 43.66 45.05 37.77
Day 12 26.45 32.23 38.55 20.69
Day 16 8.67 11.24 14.78 4.78
Day 20 2.59 6.74 9.98 0.84
Figure 3. Water retention capacity (%) of pure sandy soil (Control) and soil containing the hydrogels Agar, Composite and
HEC.
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 39
The graph in Figure 3.3 shows a continuous decrease in
water retention capacity in soil and loss of water over the
course of 20 days. The soil containing HEC hydrogel had a
greater amount of water retention than pure soil, which
served as the control. As the soil's humidity reduced, it
gradually released the water it had absorbed by diffusion.
The composite hydrogel is also possessing water retention
capacity closer to the HEC hydrogel. The average
difference between the water retention capacity of
composite and HEC hydrogels is 3.40%. At the end day of
the experiment HEC hydrogels possess a retention capacity
of 9.98%.
Table 4. ANOVA Single factor analysis for water retention in sandy amended with hydrogels at level of significance,
∝=0.05%.
ANOVA
Source of
Variation
SS df MS F P-value F crit
Between Groups 25417.33 5 5083.465 261.7814 3.77E-16 2.772853
Within Groups 349.5373 18 19.41874
Total 25766.86 23
Calculated value of F (261.78) is numerically greater than
the table value of F (2.77). Thus, the null hypothesis is
rejected and the alternative hypothesis is accepted i.e., the
three hydrogels differ significantly in their water retention
capacity in sandy soil.A short-term growth assessment was
conducted with the legume plant Vigna angularis in two
types of soil: loamy sand soil and sandy soil treated with
biodegradable hydrogels. The root length and root volume
were computed to evaluate how the hydrogels aided in the
growth of plants during water stress conditions. The root
volume, a component of root morphology, differs
significantly depending on the plant species, soil
composition, and water and mineral nutrient availability.
Thus, root volume can be used as a parameter for assessing
the drought stress conditions faced by the plants Seedlings
cultivated in non-amended soils had a greater root volume
than those grown in hydrogel-amended soils. Plants
growing in soil that has been treated with HEC
hydrogels have lesser root volume. Thus, it indicates the
efficiency of HEC hydrogels in retaining soil moisture so
that the roots do not have to penetrate deep into the soil in
search of water. As the plant is subjected to water stress
conditions, it develops a good root length to uptake more
water from the soil. So evaluating the root length is
significant in analysing the growth of plants in a drought
condition.
Table 5. Average root volume in cm3.
Type of hydrogel
Average Root
volume (in cm3) in loamy sand soil
Average Root
volume (in cm3) in sandy soil
AGAR 0.5 0.56
COMPOSITE 0.39 0.44
HEC 0.43 0.36
CONTROL 0.78 0.58
Table 6. Root growth at day 14 in Loamy sand and Sandy soil with and without hydrogel.
Type of
hydrogel
Loamy sand soil Sandy soil
Soil amended
with hydrogel
Control Soil amended with
hydrogel
Control
Agar 7.68 8.83 10.62 10.64
HEC 12.07 8.83 13.59 10.64
Composite 7.86 8.83 13.26 10.64
www.ijzab.com 39
The graph in Figure 3.3 shows a continuous decrease in
water retention capacity in soil and loss of water over the
course of 20 days. The soil containing HEC hydrogel had a
greater amount of water retention than pure soil, which
served as the control. As the soil's humidity reduced, it
gradually released the water it had absorbed by diffusion.
The composite hydrogel is also possessing water retention
capacity closer to the HEC hydrogel. The average
difference between the water retention capacity of
composite and HEC hydrogels is 3.40%. At the end day of
the experiment HEC hydrogels possess a retention capacity
of 9.98%.
Table 4. ANOVA Single factor analysis for water retention in sandy amended with hydrogels at level of significance,
∝=0.05%.
ANOVA
Source of
Variation
SS df MS F P-value F crit
Between Groups 25417.33 5 5083.465 261.7814 3.77E-16 2.772853
Within Groups 349.5373 18 19.41874
Total 25766.86 23
Calculated value of F (261.78) is numerically greater than
the table value of F (2.77). Thus, the null hypothesis is
rejected and the alternative hypothesis is accepted i.e., the
three hydrogels differ significantly in their water retention
capacity in sandy soil.A short-term growth assessment was
conducted with the legume plant Vigna angularis in two
types of soil: loamy sand soil and sandy soil treated with
biodegradable hydrogels. The root length and root volume
were computed to evaluate how the hydrogels aided in the
growth of plants during water stress conditions. The root
volume, a component of root morphology, differs
significantly depending on the plant species, soil
composition, and water and mineral nutrient availability.
Thus, root volume can be used as a parameter for assessing
the drought stress conditions faced by the plants Seedlings
cultivated in non-amended soils had a greater root volume
than those grown in hydrogel-amended soils. Plants
growing in soil that has been treated with HEC
hydrogels have lesser root volume. Thus, it indicates the
efficiency of HEC hydrogels in retaining soil moisture so
that the roots do not have to penetrate deep into the soil in
search of water. As the plant is subjected to water stress
conditions, it develops a good root length to uptake more
water from the soil. So evaluating the root length is
significant in analysing the growth of plants in a drought
condition.
Table 5. Average root volume in cm3.
Type of hydrogel
Average Root
volume (in cm3) in loamy sand soil
Average Root
volume (in cm3) in sandy soil
AGAR 0.5 0.56
COMPOSITE 0.39 0.44
HEC 0.43 0.36
CONTROL 0.78 0.58
Table 6. Root growth at day 14 in Loamy sand and Sandy soil with and without hydrogel.
Type of
hydrogel
Loamy sand soil Sandy soil
Soil amended
with hydrogel
Control Soil amended with
hydrogel
Control
Agar 7.68 8.83 10.62 10.64
HEC 12.07 8.83 13.59 10.64
Composite 7.86 8.83 13.26 10.64
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 40
Figure 4. Graphical representation of root growth at day 14 in Loamy sand and Sandy soil with and without hydrogel.
*All data are means of three replications. Statistical analysis for comparison between control and hydrogel
conditions: unpaired Student’s t-test. (p < 0.05).
The soil modified with HEC hydrogels had longer roots than plants cultivated in pure soil. The composite
hydrogel also showed a similar trend in the terms of root length. Thus, even when hydrogel with a capacity to hold
soil moisture is applied, the plants can have longer roots. According to the weight loss of each hydrogel by the soil
burial method, the percentage of degradation that took place within the short term of 12 days was computed.
Table 7. Percentage degradation of hydrogels using soil burial method.
Type of hydrogel Weight loss (%) at different time intervals
day 4 day 8 day 12
Agar 58.14 34.88 27.91
HEC 60.78 29.41 23.53
Composite 69.39 38.78 24.49
Figure 5. Graphical representation of the biodegradation of hydrogels with weight loss in percentage against different time
intervals
www.ijzab.com 40
Figure 4. Graphical representation of root growth at day 14 in Loamy sand and Sandy soil with and without hydrogel.
*All data are means of three replications. Statistical analysis for comparison between control and hydrogel
conditions: unpaired Student’s t-test. (p < 0.05).
The soil modified with HEC hydrogels had longer roots than plants cultivated in pure soil. The composite
hydrogel also showed a similar trend in the terms of root length. Thus, even when hydrogel with a capacity to hold
soil moisture is applied, the plants can have longer roots. According to the weight loss of each hydrogel by the soil
burial method, the percentage of degradation that took place within the short term of 12 days was computed.
Table 7. Percentage degradation of hydrogels using soil burial method.
Type of hydrogel Weight loss (%) at different time intervals
day 4 day 8 day 12
Agar 58.14 34.88 27.91
HEC 60.78 29.41 23.53
Composite 69.39 38.78 24.49
Figure 5. Graphical representation of the biodegradation of hydrogels with weight loss in percentage against different time
intervals
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 41
Table 8. ANOVA Single factor analysis for percentage degradation of hydrogels with level of significance, ∝=0.05%.
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 2292.587 2 1146.294 55.45581 0.00013517 5.143253
Within Groups 124.0224 6 20.6704
Total 2416.61 8
The calculated value of F (55.45) is numerically greater than the table value of F (5.14). Thus, the null hypothesis is
rejected and the alternative hypothesis is accepted i.e., the three hydrogels differ significantly in their mean percentage of
degradation.
Table 9. Percentage of moisture retention in soil and biodegradation of hydrogel.
AGAR HYDROGEL HEC HYDROGEL COMPOSITE HYDROGEL
% of Biodegra
dation
% of moisture
retention in soil
% of Biodegradat
ion
% of moisture
retention in soil
% of Biodegra
dation
% of moisture
retention in soil
Day 4 58.14 70.63 69.39 77.11 69.39 77.11
Day 8 34.88 48.45 38.78 58.67 38.78 58.67
Day 12 27.91 25.29 24.49 36.23 24.49 36.23
r* 0.95 0.92 0.96
*r= correlation coefficient
The correlation coefficient of all the three hydrogels is
above 0.9 which indicates the percentage of moisture
retention and biodegradation are positively correlated.
Thus, an increase in biodegradation leads to the release of
moisture into the soil. The agar hydrogels having firm
consistency on desiccation show a lower rate of
degradation. Thus, they can resist the instant microbial
attack. As a result, the use of agar-based hydrogels will be
appropriate for the gradual and long-term release of water
and nutrients. The HEC hydrogels were the first to show
degradation. The deterioration of HEC hydrogels started on
the second day. Thus, the HEC can be used to treat short-
term water stress scenarios. So, hydrogels manufactured
from Hydroxyethyl cellulose pose substantially less of a
harm to the environment over time. The composite
hydrogels exhibit characteristics intermediate between
HEC and agar hydrogels. Thus, composite hydrogels hold
potential for the creation of a modified hydrogel that meets
the requirements of water and environmental durability.
Hydrogels synthesized from hydroxyethyl cellulose (HEC)
through chemical polymerization showed the highest water
absorbency at 50.76%. Among the three tested types, water
absorption followed the order: agar (12.39%), composite
(36.85%), and HEC outperforming the others by a margin
of 38.37% over agar. The high hydrophilicity of HEC, due
to its abundant hydroxyl groups, enables faster and more
efficient water uptake, making it potentially beneficial for
improving soil moisture after short rainfall events.
In comparison, synthetic hydrogels have significantly
higher absorption capacities. Vundavalli et al. (2015)
reported silver-coated super-absorbent polymers absorbing
up to 190 g/g in distilled water, 161 g/g for tap water, and
119 g/g for saline water. While Akhtar et al. (2004) found
values as high as 505 g/g using hydrogels based on acrylic
acid salts. These findings highlight that synthetic hydrogels
outperform biodegradable, natural polymer-based
hydrogels in water absorption efficiency. Soils treated with
hydrogels retained significantly more moisture, confirming
their water absorption capacity. HEC hydrogel showed the
highest retention in both loamy sand and sandy soils,
followed by the composite and agar hydrogels. During the
20-day experiment, hydrogels gradually released stored
water as soil moisture declined. On day 4, loamy sand
control soil retained 71.74% moisture, while HEC, agar,
and composite hydrogels retained 80%, 77.11%, and
70.63%, respectively. In sandy soil, due to higher
permeability, retention dropped to 67.03% (HEC), 64.34%
(composite), and 60.87% (agar).
By day 20, loamy sand treated with HEC retained 9.09%
moisture (control: 3.19%), and sandy soil retained 9.98%
(control: 0.84%). Composite and agar hydrogels also
improved water retention, though to a lesser extent. These
findings suggest that hydrogels can help maintain soil
moisture during dry periods by slowly releasing absorbed
water. Cheng et al. (2018) discovered that adding super-
absorbents to sandy loam, loam, and paddy soil
considerably improved the soil's water holding capacity
and retention qualities. After 8 days, the relative water
content of sandy soil, loam soil, and paddy soil treated with
super absorbent was 42%, 56%, and 45%, respectively.
However, the relative water content of soils (sandy loam,
loam, and paddy soil) without hydrogels was only 2%,
www.ijzab.com 41
Table 8. ANOVA Single factor analysis for percentage degradation of hydrogels with level of significance, ∝=0.05%.
ANOVA
Source of Variation SS df MS F P-value F crit
Between Groups 2292.587 2 1146.294 55.45581 0.00013517 5.143253
Within Groups 124.0224 6 20.6704
Total 2416.61 8
The calculated value of F (55.45) is numerically greater than the table value of F (5.14). Thus, the null hypothesis is
rejected and the alternative hypothesis is accepted i.e., the three hydrogels differ significantly in their mean percentage of
degradation.
Table 9. Percentage of moisture retention in soil and biodegradation of hydrogel.
AGAR HYDROGEL HEC HYDROGEL COMPOSITE HYDROGEL
% of Biodegra
dation
% of moisture
retention in soil
% of Biodegradat
ion
% of moisture
retention in soil
% of Biodegra
dation
% of moisture
retention in soil
Day 4 58.14 70.63 69.39 77.11 69.39 77.11
Day 8 34.88 48.45 38.78 58.67 38.78 58.67
Day 12 27.91 25.29 24.49 36.23 24.49 36.23
r* 0.95 0.92 0.96
*r= correlation coefficient
The correlation coefficient of all the three hydrogels is
above 0.9 which indicates the percentage of moisture
retention and biodegradation are positively correlated.
Thus, an increase in biodegradation leads to the release of
moisture into the soil. The agar hydrogels having firm
consistency on desiccation show a lower rate of
degradation. Thus, they can resist the instant microbial
attack. As a result, the use of agar-based hydrogels will be
appropriate for the gradual and long-term release of water
and nutrients. The HEC hydrogels were the first to show
degradation. The deterioration of HEC hydrogels started on
the second day. Thus, the HEC can be used to treat short-
term water stress scenarios. So, hydrogels manufactured
from Hydroxyethyl cellulose pose substantially less of a
harm to the environment over time. The composite
hydrogels exhibit characteristics intermediate between
HEC and agar hydrogels. Thus, composite hydrogels hold
potential for the creation of a modified hydrogel that meets
the requirements of water and environmental durability.
Hydrogels synthesized from hydroxyethyl cellulose (HEC)
through chemical polymerization showed the highest water
absorbency at 50.76%. Among the three tested types, water
absorption followed the order: agar (12.39%), composite
(36.85%), and HEC outperforming the others by a margin
of 38.37% over agar. The high hydrophilicity of HEC, due
to its abundant hydroxyl groups, enables faster and more
efficient water uptake, making it potentially beneficial for
improving soil moisture after short rainfall events.
In comparison, synthetic hydrogels have significantly
higher absorption capacities. Vundavalli et al. (2015)
reported silver-coated super-absorbent polymers absorbing
up to 190 g/g in distilled water, 161 g/g for tap water, and
119 g/g for saline water. While Akhtar et al. (2004) found
values as high as 505 g/g using hydrogels based on acrylic
acid salts. These findings highlight that synthetic hydrogels
outperform biodegradable, natural polymer-based
hydrogels in water absorption efficiency. Soils treated with
hydrogels retained significantly more moisture, confirming
their water absorption capacity. HEC hydrogel showed the
highest retention in both loamy sand and sandy soils,
followed by the composite and agar hydrogels. During the
20-day experiment, hydrogels gradually released stored
water as soil moisture declined. On day 4, loamy sand
control soil retained 71.74% moisture, while HEC, agar,
and composite hydrogels retained 80%, 77.11%, and
70.63%, respectively. In sandy soil, due to higher
permeability, retention dropped to 67.03% (HEC), 64.34%
(composite), and 60.87% (agar).
By day 20, loamy sand treated with HEC retained 9.09%
moisture (control: 3.19%), and sandy soil retained 9.98%
(control: 0.84%). Composite and agar hydrogels also
improved water retention, though to a lesser extent. These
findings suggest that hydrogels can help maintain soil
moisture during dry periods by slowly releasing absorbed
water. Cheng et al. (2018) discovered that adding super-
absorbents to sandy loam, loam, and paddy soil
considerably improved the soil's water holding capacity
and retention qualities. After 8 days, the relative water
content of sandy soil, loam soil, and paddy soil treated with
super absorbent was 42%, 56%, and 45%, respectively.
However, the relative water content of soils (sandy loam,
loam, and paddy soil) without hydrogels was only 2%,
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 42
18%, and 4%. Previous research found that adding typical
hydrophilic polymers to sandy soil increased its water
retention capacity to levels equal to silty clay or loam soils
(Johnson, 1984; Hutterman et al., 1999). Shahid et al.
(2012) observed that adding 0.1 to 0.4% (w/w) of a poly-
acrylamide-based superabsorbent hydrogel enhanced the
water retention of a sandy loam soil by 60 to 100% at field
capacity, with the water retention rising with the quantity
of the hydrogel. Similar results were obtained on a sandy
soil treated with hydrogel, although the hydrogel influence
decreased as soil salinity spiked, confirming a common
problem with hydrogels (Dorraji et al., 2010).
Seedlings grown in untreated soils had larger root
volumes (0.78 cm³ in loamy sand and 0.58 cm³ in sandy
soil) compared to those in hydrogel-treated soils. In loamy
sand, root volumes with agar, composite, and HEC
hydrogels were 0.5 cm³, 0.39 cm³, and 0.43 cm³,
respectively. In sandy soil, the values were 0.56 cm³ (agar),
0.44 cm³ (composite), and 0.36 cm³ (HEC). The reduced
root volumes in HEC-treated soil indicate improved
moisture availability near the surface, reducing the need for
deeper root growth. Despite smaller root volumes,
seedlings in HEC-amended soils had longer roots—12.07
cm (loamy sand) and 13.59 cm (sandy soil)—suggesting
that water-retentive hydrogels like HEC support root
elongation. Composite hydrogels showed a similar trend,
indicating that moisture-retentive soils still support root
growth.Cheng et al. (2018) found that super-absorbents
play a crucial role in maize seed development.
Measurements of seeding lengths demonstrated that
hydrogels treatment at concentrations lower than 0.2%
improved root growth. Maize seeds treated with hydrogels
produced significantly longer average seedling lengths than
the control groups, which included sandy loam, loam, and
paddy soils. The 0.2% treatments had the longest seedling
height of all the groups, about double that of the 0% and
0.5% treatments combined. Montesano et al. (2015) found
that the cucumber culture experiment results demonstrated
an overall increase in plant growth when treated to
hydrogel treatment at the time of analysis. The hydrogel
increased the plants' height (180 vs. 158 cm), total fresh
biomass (1753 vs. 913 g), leaf, stem, and fruit fresh
biomass (468 vs. 285 g, 427 vs. 264, and 858 vs. 364,
respectively), and leaf area. The findings support the
widely documented favorable benefits of hydrogels on
plant development and the decrease of the negative effects
of water stress (Akhter et al., 2004; Shahid et al., 2012).
The percentage of weight loss on the fourth day of soil
burial was 58.14% for agar, 60.78% for HEC, and 69.39%
for composite hydrogels. The agar hydrogels decomposed
slower than the other hydrogels. This could account for the
hydrogel's hard consistency. The moisture provided by the
hydrogels on day 4 is 70.63% for agar, 80% HEC, and
77.11% composite hydrogels. The correlation analysis of
the percentage of soil moisture and degradation of
hydrogels in weight percentage showed that there exists a
highly positive correlation between them. Thus, the gradual
degradation of the hydrogels leads to the release of
moisture into the soil. Melendres et al. (2022) reported a
reduction in absorption capacity and permeability after
subjecting samples to biodegradability tests in a high-
humidity environment at around 33˚C. Rop et al. (2019)
noted slow mass loss in cellulose-grafted polymer hydrogel
during the first four weeks, followed by a quicker loss from
the fourth to the twelfth week. Polymer hydrogels lacking
cellulose showed no significant mass change. After 14
weeks, the mass loss was around 25% for cellulose-grafted
polymer hydrogel and 5% for polymer hydrogel without
cellulose.
CONCLUSION
The current study describes a set of hydrogels that can be
created without much sophisticated technique in a cost-
effective manner. The uniqueness of these hydrogels is
their immediate preparation and use by the farmers
themselves. The components used for the preparation are
both eco-friendly and non-toxic. The water absorption
capacity, the percentage of water retention in loamy sand
soil and sandy soil, the growth of seeds in hydrogel-added
soil, and the biodegradability of the hydrogels were
evaluated. Hydroxyethyl cellulose (HEC) hydrogels are the
most promising form of biodegradable hydrogel that has
the potential for maximum water absorbency and water
retention. As they could provide enough moisture to the
soil, they helped the plants surpass the water stress
condition for a good period of time. Even the growth of the
seedlings during a water shortage is not affected much if
the soil is altered with a suitable amount of hydrogel. Thus,
the tested hydrogel proved to be suitable for potential use
in agriculture, with a particular potential benefit for short-
growing cycle crops. The other two formulations of
hydrogels, composite hydrogel and agar hydrogel, have the
ability to retain moisture, even though at a lower rate.
Thus, they can be further modified with the combination of
other natural polymers with similar properties to create
more diverse types of biodegradable hydrogels.
ACKNOWLEDGMENT
The authors are thankful to Alphonsa College Pala,
Kottayam for providing technical support under DBT star
college scheme.
CONFLICT OF INTERESTS
The authors declare no conflict of interest
ETHICS APPROVAL
The authors are confirming that all ethical issues have been
dealt with the research ethics guidelines provided by the
PG and Research Department of Zoology, Alphonsa
College Pala, Kottayam, Kerala.
FUNDING
This study received no specific funding from public,
commercial, or not-for-profit funding agencies.
www.ijzab.com 42
18%, and 4%. Previous research found that adding typical
hydrophilic polymers to sandy soil increased its water
retention capacity to levels equal to silty clay or loam soils
(Johnson, 1984; Hutterman et al., 1999). Shahid et al.
(2012) observed that adding 0.1 to 0.4% (w/w) of a poly-
acrylamide-based superabsorbent hydrogel enhanced the
water retention of a sandy loam soil by 60 to 100% at field
capacity, with the water retention rising with the quantity
of the hydrogel. Similar results were obtained on a sandy
soil treated with hydrogel, although the hydrogel influence
decreased as soil salinity spiked, confirming a common
problem with hydrogels (Dorraji et al., 2010).
Seedlings grown in untreated soils had larger root
volumes (0.78 cm³ in loamy sand and 0.58 cm³ in sandy
soil) compared to those in hydrogel-treated soils. In loamy
sand, root volumes with agar, composite, and HEC
hydrogels were 0.5 cm³, 0.39 cm³, and 0.43 cm³,
respectively. In sandy soil, the values were 0.56 cm³ (agar),
0.44 cm³ (composite), and 0.36 cm³ (HEC). The reduced
root volumes in HEC-treated soil indicate improved
moisture availability near the surface, reducing the need for
deeper root growth. Despite smaller root volumes,
seedlings in HEC-amended soils had longer roots—12.07
cm (loamy sand) and 13.59 cm (sandy soil)—suggesting
that water-retentive hydrogels like HEC support root
elongation. Composite hydrogels showed a similar trend,
indicating that moisture-retentive soils still support root
growth.Cheng et al. (2018) found that super-absorbents
play a crucial role in maize seed development.
Measurements of seeding lengths demonstrated that
hydrogels treatment at concentrations lower than 0.2%
improved root growth. Maize seeds treated with hydrogels
produced significantly longer average seedling lengths than
the control groups, which included sandy loam, loam, and
paddy soils. The 0.2% treatments had the longest seedling
height of all the groups, about double that of the 0% and
0.5% treatments combined. Montesano et al. (2015) found
that the cucumber culture experiment results demonstrated
an overall increase in plant growth when treated to
hydrogel treatment at the time of analysis. The hydrogel
increased the plants' height (180 vs. 158 cm), total fresh
biomass (1753 vs. 913 g), leaf, stem, and fruit fresh
biomass (468 vs. 285 g, 427 vs. 264, and 858 vs. 364,
respectively), and leaf area. The findings support the
widely documented favorable benefits of hydrogels on
plant development and the decrease of the negative effects
of water stress (Akhter et al., 2004; Shahid et al., 2012).
The percentage of weight loss on the fourth day of soil
burial was 58.14% for agar, 60.78% for HEC, and 69.39%
for composite hydrogels. The agar hydrogels decomposed
slower than the other hydrogels. This could account for the
hydrogel's hard consistency. The moisture provided by the
hydrogels on day 4 is 70.63% for agar, 80% HEC, and
77.11% composite hydrogels. The correlation analysis of
the percentage of soil moisture and degradation of
hydrogels in weight percentage showed that there exists a
highly positive correlation between them. Thus, the gradual
degradation of the hydrogels leads to the release of
moisture into the soil. Melendres et al. (2022) reported a
reduction in absorption capacity and permeability after
subjecting samples to biodegradability tests in a high-
humidity environment at around 33˚C. Rop et al. (2019)
noted slow mass loss in cellulose-grafted polymer hydrogel
during the first four weeks, followed by a quicker loss from
the fourth to the twelfth week. Polymer hydrogels lacking
cellulose showed no significant mass change. After 14
weeks, the mass loss was around 25% for cellulose-grafted
polymer hydrogel and 5% for polymer hydrogel without
cellulose.
CONCLUSION
The current study describes a set of hydrogels that can be
created without much sophisticated technique in a cost-
effective manner. The uniqueness of these hydrogels is
their immediate preparation and use by the farmers
themselves. The components used for the preparation are
both eco-friendly and non-toxic. The water absorption
capacity, the percentage of water retention in loamy sand
soil and sandy soil, the growth of seeds in hydrogel-added
soil, and the biodegradability of the hydrogels were
evaluated. Hydroxyethyl cellulose (HEC) hydrogels are the
most promising form of biodegradable hydrogel that has
the potential for maximum water absorbency and water
retention. As they could provide enough moisture to the
soil, they helped the plants surpass the water stress
condition for a good period of time. Even the growth of the
seedlings during a water shortage is not affected much if
the soil is altered with a suitable amount of hydrogel. Thus,
the tested hydrogel proved to be suitable for potential use
in agriculture, with a particular potential benefit for short-
growing cycle crops. The other two formulations of
hydrogels, composite hydrogel and agar hydrogel, have the
ability to retain moisture, even though at a lower rate.
Thus, they can be further modified with the combination of
other natural polymers with similar properties to create
more diverse types of biodegradable hydrogels.
ACKNOWLEDGMENT
The authors are thankful to Alphonsa College Pala,
Kottayam for providing technical support under DBT star
college scheme.
CONFLICT OF INTERESTS
The authors declare no conflict of interest
ETHICS APPROVAL
The authors are confirming that all ethical issues have been
dealt with the research ethics guidelines provided by the
PG and Research Department of Zoology, Alphonsa
College Pala, Kottayam, Kerala.
FUNDING
This study received no specific funding from public,
commercial, or not-for-profit funding agencies.
Sherin C Baby et al. Int. J. Zool. Appl. Biosci., 10(5), 34-44, 2025
www.ijzab.com 43
AI TOOL DECLARATION
The authors declares that no AI and related tools are used to
write the scientific content of this manuscript.
DATA AVAILABILITY
Data will be available on request
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Alam, M. N., & Christopher, L. P. (2018). Natural
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A., Alghamdi, N. A., Wageh, S., Ramesh, K., & Ramesh,
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properties, and their applications. Polymers, 12(11), 2702.
https://doi.org/10.3390/polym12112702
Cheng, D., Liu, Y., Yang, G., & Zhang, A. (2018). Water-
and fertilizer-integrated hydrogel derived from the
polymerization of acrylic acid and urea as a slow-release
N fertilizer and water retention in agriculture. Journal of
Agricultural and Food Chemistry, 66(23), 5762–5769.
https://doi.org/10.1021/acs.jafc.8b00872
Cuadri, A., Bengoechea, C., Romero, A., & Guerrero, A.
(2016). A natural-based polymeric hydrogel based on
functionalized soy protein. European Polymer Journal,
85, 164–174.
https://doi.org/10.1016/j.eurpolymj.2016.10.026
Demitri, C., Scalera, F., Madaghiele, M., Sannino, A., &
Maffezzoli, A. (2013). Potential of cellulose-based
superabsorbent hydrogels as water reservoir in
agriculture. International Journal of Polymer Science,
2013, 1-6. https://doi.org/10.1155/2013/435073
Heise, K., Kirsten, M., Schneider, Y., Jaros, D., Keller, H.,
Rohm, H., Kalbitz, K., & Fischer, S. (2019). From
agricultural byproducts to value-added materials: Wheat
straw-based hydrogels as soil conditioners? ACS
Sustainable Chemistry & Engineering, 7(9), 8604–8612.
https://doi.org/10.1021/acssuschemeng.9b00378
Hüttermann, A., Zommorodi, M., & Reise, K. (1999).
Addition of hydrogels to soil for prolonging the survival
of Pinus halepensis seedlings subjected to drought. Soil &
Tillage Research, 50(3–4), 295–304.
https://doi.org/10.1016/s0167-1987(99)00023-9
Johnson, M. S. (1984). The effects of gel‐forming
polyacrylamides on moisture storage in sandy soils.
Journal of the Science of Food and Agriculture, 35(11),
1196–1200. https://doi.org/10.1002/jsfa.27403511
Kabir, S. M. F., Sikdar, P. P., Haque, B., Bhuiyan, M. A.
R., Ali, A., & Islam, M. N. (2018). Cellulose-based
hydrogel materials: Chemistry, properties and their
prospective applications. Progress in Biomaterials, 7(3),
153–174. https://doi.org/10.1007/s40204-018-0095-0
Karnani, S. (2017). Hydrogel agriculture technology.
Retrieved from https://vikaspedia.in/agriculture/best-
practices/sustainable-agriculture/crop-
management/hydrogel-agriculture-technology
Melendres, A. V., Manacob, C. J. A., & Vera Cruz, R. P.
(2022). Effect of corn starch on the biodegradability and
absorbency of superabsorbent polymer. Chemical
Engineering Transactions, 92, 427–432.
https://doi.org/10.3303/CET2292072
Mishra, S., Thombare, N., Ali, M., & Swami, S. (2018).
Applications of biopolymeric gels in agricultural sector.
In Polymer gels (pp. 185–228). Singapore: Springer.
https://doi.org/10.1007/978-981-10-6080-9_8
Montesano, F. F., Parente, A., Santamaria, P., Sannino, A.,
& Serio, F. (2015). Biodegradable superabsorbent
hydrogel increases water retention properties of growing
media and plant growth. Agriculture and Agricultural
Science Procedia, 4, 451–458.
https://doi.org/10.1016/j.aaspro.2015.03.052
Oladosu, Y., Rafii, M. Y., Arolu, F., Chukwu, S. C., Salisu,
M. A., Fagbohun, I. K., Muftaudeen, T. K., Swaray, S., &
Haliru, B. S. (2022). Superabsorbent polymer hydrogels
for sustainable agriculture: A review. Horticulturae, 8(7),
605. https://doi.org/10.3390/horticulturae8070605
Rop, K., Mbui, D., Njomo, N., Karuku, G. N., Michira, I.,
& Ajayi, R. F. (2019). Biodegradable water hyacinth
cellulose-graft-poly (ammonium acrylate-co-acrylic acid)
polymer hydrogel for potential agricultural application.
Heliyon, 5(3), e01416.
https://doi.org/10.1016/j.heliyon.2019.e01416
Shahid, S. A., Qidwai, A. A., Anwar, F., Ullah, I., &
Rashid, U. (2012). Improvement in the water retention
characteristics of sandy loam soil using a newly
synthesized poly (acrylamide-co-acrylic
acid)/AlZnFe2O4 superabsorbent hydrogel
nanocomposite material. Molecules, 17(8), 9397–9412.
https://doi.org/10.3390/molecules17089397
Slutz, S. (2023). Can biodegradable hydrogels help
conserve water in farming? Retrieved from
https://www.sciencebuddies.org/science-fair-
projects/project_ideas/AgTech_p013/agricultural-
technology/water-conservation-hydrogels
Sulianto, A. A., Adiyaksa, I. P., Wibisono, Y., Khan, E.,
Ivanov, A., Drannikov, A., Ozaltin, K., & Di Martino, A.
(2023). From fruit waste to hydrogels for agricultural
applications. Clean Technologies, 6(1), 1.
https://doi.org/10.3390/cleantechnol6010001
www.ijzab.com 43
AI TOOL DECLARATION
The authors declares that no AI and related tools are used to
write the scientific content of this manuscript.
DATA AVAILABILITY
Data will be available on request
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and fertilizer-integrated hydrogel derived from the
polymerization of acrylic acid and urea as a slow-release
N fertilizer and water retention in agriculture. Journal of
Agricultural and Food Chemistry, 66(23), 5762–5769.
https://doi.org/10.1021/acs.jafc.8b00872
Cuadri, A., Bengoechea, C., Romero, A., & Guerrero, A.
(2016). A natural-based polymeric hydrogel based on
functionalized soy protein. European Polymer Journal,
85, 164–174.
https://doi.org/10.1016/j.eurpolymj.2016.10.026
Demitri, C., Scalera, F., Madaghiele, M., Sannino, A., &
Maffezzoli, A. (2013). Potential of cellulose-based
superabsorbent hydrogels as water reservoir in
agriculture. International Journal of Polymer Science,
2013, 1-6. https://doi.org/10.1155/2013/435073
Heise, K., Kirsten, M., Schneider, Y., Jaros, D., Keller, H.,
Rohm, H., Kalbitz, K., & Fischer, S. (2019). From
agricultural byproducts to value-added materials: Wheat
straw-based hydrogels as soil conditioners? ACS
Sustainable Chemistry & Engineering, 7(9), 8604–8612.
https://doi.org/10.1021/acssuschemeng.9b00378
Hüttermann, A., Zommorodi, M., & Reise, K. (1999).
Addition of hydrogels to soil for prolonging the survival
of Pinus halepensis seedlings subjected to drought. Soil &
Tillage Research, 50(3–4), 295–304.
https://doi.org/10.1016/s0167-1987(99)00023-9
Johnson, M. S. (1984). The effects of gel‐forming
polyacrylamides on moisture storage in sandy soils.
Journal of the Science of Food and Agriculture, 35(11),
1196–1200. https://doi.org/10.1002/jsfa.27403511
Kabir, S. M. F., Sikdar, P. P., Haque, B., Bhuiyan, M. A.
R., Ali, A., & Islam, M. N. (2018). Cellulose-based
hydrogel materials: Chemistry, properties and their
prospective applications. Progress in Biomaterials, 7(3),
153–174. https://doi.org/10.1007/s40204-018-0095-0
Karnani, S. (2017). Hydrogel agriculture technology.
Retrieved from https://vikaspedia.in/agriculture/best-
practices/sustainable-agriculture/crop-
management/hydrogel-agriculture-technology
Melendres, A. V., Manacob, C. J. A., & Vera Cruz, R. P.
(2022). Effect of corn starch on the biodegradability and
absorbency of superabsorbent polymer. Chemical
Engineering Transactions, 92, 427–432.
https://doi.org/10.3303/CET2292072
Mishra, S., Thombare, N., Ali, M., & Swami, S. (2018).
Applications of biopolymeric gels in agricultural sector.
In Polymer gels (pp. 185–228). Singapore: Springer.
https://doi.org/10.1007/978-981-10-6080-9_8
Montesano, F. F., Parente, A., Santamaria, P., Sannino, A.,
& Serio, F. (2015). Biodegradable superabsorbent
hydrogel increases water retention properties of growing
media and plant growth. Agriculture and Agricultural
Science Procedia, 4, 451–458.
https://doi.org/10.1016/j.aaspro.2015.03.052
Oladosu, Y., Rafii, M. Y., Arolu, F., Chukwu, S. C., Salisu,
M. A., Fagbohun, I. K., Muftaudeen, T. K., Swaray, S., &
Haliru, B. S. (2022). Superabsorbent polymer hydrogels
for sustainable agriculture: A review. Horticulturae, 8(7),
605. https://doi.org/10.3390/horticulturae8070605
Rop, K., Mbui, D., Njomo, N., Karuku, G. N., Michira, I.,
& Ajayi, R. F. (2019). Biodegradable water hyacinth
cellulose-graft-poly (ammonium acrylate-co-acrylic acid)
polymer hydrogel for potential agricultural application.
Heliyon, 5(3), e01416.
https://doi.org/10.1016/j.heliyon.2019.e01416
Shahid, S. A., Qidwai, A. A., Anwar, F., Ullah, I., &
Rashid, U. (2012). Improvement in the water retention
characteristics of sandy loam soil using a newly
synthesized poly (acrylamide-co-acrylic
acid)/AlZnFe2O4 superabsorbent hydrogel
nanocomposite material. Molecules, 17(8), 9397–9412.
https://doi.org/10.3390/molecules17089397
Slutz, S. (2023). Can biodegradable hydrogels help
conserve water in farming? Retrieved from
https://www.sciencebuddies.org/science-fair-
projects/project_ideas/AgTech_p013/agricultural-
technology/water-conservation-hydrogels
Sulianto, A. A., Adiyaksa, I. P., Wibisono, Y., Khan, E.,
Ivanov, A., Drannikov, A., Ozaltin, K., & Di Martino, A.
(2023). From fruit waste to hydrogels for agricultural
applications. Clean Technologies, 6(1), 1.
https://doi.org/10.3390/cleantechnol6010001
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polymer materials: A review. Iranian Polymer Journal,
17(6), 451-477.
www.ijzab.com 44
Vo, T. S., Vo, T. T. B. C., Tran, T. T., & Pham, N. D.
(2022). Enhancement of water absorption capacity and
compressibility of hydrogel sponges prepared from
gelatin/chitosan matrix with different polyols. Progress in
Natural Science, 32(1), 54-62.
https://doi.org/10.1016/j.pnsc.2021.10.001
Vundavalli, R., Vundavalli, S., Nakka, M., & Rao, D. S.
(2015). Biodegradable nano-hydrogels in agricultural
farming – Alternative source for water resources.
Procedia Materials Science, 10, 548-554.
https://doi.org/10.1016/j.mspro.2015.06.005
Xiong, B., Loss, R. D., Shields, D., Pawlik, T., Hochreiter,
R., Zydney, A. L., & Kumar, M. (2018). Polyacrylamide
degradation and its implications in environmental systems.
npj Clean Water, 1(17), 1-9.
https://doi.org/10.1038/s41545-018-0016-8
Zhou, X., Zhang, P., Zhao, F., & Yu, G. (2020). Super
moisture absorbent gels for sustainable agriculture via
atmospheric water irrigation. ACS Materials Letters,
2(11), 1419-1422.
https://doi.org/10.1021/acsmaterialslett.0c00439
Zohuriaan, J., & Kabiri, K. (2008). Superabsorbent
polymer materials: A review. Iranian Polymer Journal,
17(6), 451-477.