Agricultural Soil Quality Research Articles

Assessment of intensive periurban agriculture soil quality applying biomarkers in earthworms

Periurban agriculture in Argentina is carried out by farmers without adequate control. The indiscriminate agrochemical application for productivity improvement negatively impacts the environment. The objective of this work was to test the quality of periurban agricultural soils by performing bioassays with Eisenia andrei as an indicator. Soils belonging to two orchards with intensive production (S: strawberry/broccoli crop plot and G: tomato/pepper crop greenhouse - Moreno District, Buenos Aires, Argentina) were sampled during 2015 and 2016. As subcellular biomarkers, cholinesterases (ChE), carboxylesterases (CaE), and glutathione-S-transferases (GST) activities were analysed in E. andrei (7-day exposure). While no effect on ChE activities was observed, CaE activities were significantly reduced 18% (S-2016 soil). GST activities were increased 35% and 30% by S-2016 and G-2016, respectively. CaE decrease together with GST increase could be indicative of a negative disturbance. Concerning whole organism biomarkers, reproduction (56-day exposure), avoidance (3-day exposure), and feeding activity (bait-lamina test, 3-day exposure) were analysed. A reduced cocoons’ viability (50%), hatchability (55%), accompanied by a low number of juveniles (50%) were observed in all cases. Additionally, the earthworms exhibited significant avoidance responses to S-2015, S-2016 and G-2016 whereas G-2015 soil induced migration. No significant effect on the feeding activity was registered in any case. Most of the E. andrei biomarkers tested could constitute an early warning of harmful effects produced by polluted periurban soils, even if the agrochemical treatment applied remains unknown. The results reveal the need to develop an action plan to avoid further deterioration of the productive soil.

Health risk assessment of trace metal(loid)s in agricultural soil using an integrated model combining soil-related and plants-accumulation exposures: A case study on Hainan Island, South China

Traditional health risk assessment of trace metal(loid)s (TMs) in agricultural soil exclusively considers direct soil-related exposure and may underestimate the health risks they pose. In this study, the health risks of TMs were evaluated using an integrated model that combined soil-related and plant-accumulating exposures. A detailed investigation of common TMs (Cr, Pb, Cd, As, and Hg) coupled with probability risk analysis based on a Monte Carlo simulation was conducted on Hainan Island. Our results showed that, except for As, the non-carcinogenic risk (HI) and carcinogenic risk (CR) of the TMs were all within the acceptable ranges (HI < 1.0, and CR < 1E−06) for direct soil-related exposure to bio-accessible fractions and indirect exposure via plant accumulation (CR substantially lower than the warning threshold 1E−04). We identified crop food ingestion as the essential pathway for TM exposure and As as the critical toxic element in terms of risk control. Moreover, we determined that RfDo and SFo are the most suitable parameters for assessing As health risk severity. Our study demonstrated that the proposed integrated model combining soil-related and plant-accumulating exposures can avoid major health risk assessment deviations. The results obtained and the integrated model proposed in this study can facilitate future multi-pathway exposure research and could be the basis for determining agricultural soil quality criteria in tropical areas.

Environmental and economic benefits of wheat and chickpea crop rotation in the Mediterranean region of Apulia (Italy)

Wheat plays an essential role in safeguarding global food security. However, its intensive agricultural production, aimed at maximizing crop yields and associated economic benefits, jeopardizes many ecosystem services and the economic stability of farmers. Rotations with leguminous are recognized as a promising strategy in favor of sustainable agriculture. However, not all crop rotations are suitable for promoting sustainability and their implications on agricultural soil and crop quality should be carefully analyzed. This research aims to demonstrate the environmental and economic benefits of introducing chickpea into a wheat-based system under Mediterranean pedo-climatic conditions. For this purpose, the crop rotation “wheat-chickpea” was evaluated and compared with the conventional regime (wheat monoculture) by means of life cycle assessment methodology. For this purpose, inventory data (e.g., agrochemical doses, machinery, energy consumption, production yield, among others) was compiled for each crop and cropping system, thus converted into environmental impacts based on two functional units: 1 ha per year and one € of gross margin. Eleven environmental indicators were analyzed, including soil quality and biodiversity loss. Results indicate that chickpea-wheat rotation system offers lower environmental impacts, regardless of the functional unit considered. Global warming (18 %) and freshwater ecotoxicity (20 %) were the categories with the largest reductions. Furthermore, a remarkable increase (96 %) in gross margin was observed with the rotation system, due to the low cost of chickpea cultivation and its higher market price. Nevertheless, proper fertilizer management remains essential to fully attain the environmental benefits of crop rotation with legumes.

Source and health risk assessment of soil polycyclic aromatic hydrocarbons under straw burning condition in Changchun City, China

Changchun, China is located in one of the world's three golden corn belts. As a key commodity grain base in China, Changchun plays a vital role in providing food security in the northeast. A total of 16 polycyclic aromatic hydrocarbons (PAHs) was analyzed to determine the influence of anthropogenic activities on the environmental quality of agricultural soils under straw burning conditions. The polycyclic aromatic hydrocarbons soil contamination severity was evaluated using the Maliszewska-Kordybach method. The results indicated that the agricultural soils of Changchun are substantial contaminated with PAHs. Petroleum, biomass, and coal combustion are the primary sources of PAH and have been determined using principal component analysis (PCA) and the isomeric ratio approach. The degree of hazard to human health was assessed using toxicity equivalence and increased lifetime cancer risk (ILCR) factors, except in localized areas during adulthood, the general risk was found to be modest. This study provides important information on PAH exposure in agricultural soils in northeast China, and the findings aid in the exploitation of straw and the mitigation of soil environmental concerns, allowing northeast China to achieve green agricultural development.

Impact of glyphosate on agricultural soil quality in ICR, Arunachal Pradesh

Impact of glyphosate on agricultural soil quality in ICR, Arunachal Pradesh

Towards defining soil quality of Mediterranean calcareous agricultural soils: Reference values and potential core indicator set

To avoid soil degradation, adapt to climate change and comply with the Sustainable Development goals 2030 (UN General Assembly), establishing the quality/fertility of the agricultural soils of the Mediterranean region and evaluate how these evolve with time is mandatory. This enables adequate management practices to be implemented. The Mediterranean calcareous region has received little attention in this sense, in spite its soil particularities. So, 24 different representative calcareous agricultural soils of the Mediterranean region, including the main management strategies of agricultural soils (rainfed and irrigated), were sampled from the island of Mallorca; and their physical, chemical and biological properties determined. The values obtained for most of the soil characteristics allowed to establish an initial approach to the reference values for the type of calcareous agricultural soils considered, and to clearly distinguish the effect of rainfed or irrigation management practices on soils properties and dynamics. Some enzyme activities were not stimulated by the irrigation conditions assayed or they were only in dry conditions, suggesting optimum enzyme activities could be obtained when alternating dry and humid soil conditions. Soil organic carbon, calcium carbonate and active lime revealed of significant importance in the collection of soils. Finally, the results obtained clearly indicate the heterogeneity of the region and its implications on the different soil characteristics. Therefore, this study could serve as a starting point to adequately establish the quality (fertility) for Mediterranean calcareous agricultural soils and their reference values by conducting further research in this region and including more type of soils.

Reduction in the Use of Some Herbicides Favors Nitrogen Fixation Efficiency in Phaseolus vulgaris and Medicago sativa.

In recent decades, the quality of agricultural soils has been seriously affected by the excessive application of pesticides, with herbicides being one of the most abundant. Continuous use of herbicides alters the soil microbial community and beneficial interactions between plants and bacteria such as legume-rhizobia spp. symbiosis, causing a decrease in the biological nitrogen fixation, which is essential for soil fertility. Therefore, the aim of this work was to study the effect of two commonly used herbicides (pendimethalin and clethodim) on the legume-rhizobia spp. symbiosis to improve the effectiveness of this process. Phaseolus vulgaris plants grown in pots with a mixture of soil:perlite (3:1 v/v), showed a 44% inhibition of nitrogen fixation rate with pendimethalin. However, clethodim, specifically used against monocots, did not induce significant differences. Additionally, we analyzed the effect of herbicides on root exudate composition, detecting alterations that might be interfering with the symbiosis establishment. In order to assess the effect of the herbicides at the early nodulation steps, nodulation kinetics in Medicago sativa plants inoculated with Sinorhizobium meliloti were performed. Clethodim caused a 30% reduction in nodulation while pendimethalin totally inhibited nodulation, producing a reduction in bacterial growth and motility as well. In conclusion, pendimethalin and clethodim application reduced the capacity of Phaseolus vulgaris and Medicago sativa to fix nitrogen by inhibiting root growth and modifying root exudate composition as well as bacterial fitness. Thus, a reduction in the use of these herbicides in these crops should be addressed to favor a state of natural fertilization of the soil through greater efficiency of leguminous crops.

Trace elements in farmland soils and crops, and probabilistic health risk assessment in areas influenced by mining activity in Ecuador

Consumption of food grown in contaminated soils may be a significant human exposure pathway to pollutants, including toxic elements. This study aimed to investigate the pollution level of trace elements in farmland soil and crops collected in orchards from Ponce Enriquez, one of the Ecuador’s most important gold mining areas. The concentration of arsenic (As), cadmium (Cd), chrome (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) was analyzed in soil and crop samples (celery, chives, corn, herbs, lettuce, turnips, green beans, cassava, and carrots). In addition, a probabilistic human health risk assessment, in terms of hazard quotients (HQ) and cancer risk (CR), was conducted to assess the potential risk related to local crop ingestion. The contents of As, Cr, Cu, and Ni in soils exceeded the Ecuadorian quality guidelines for agricultural soils. The trace elements concentration in local crops was higher than the maximum permissible levels set by the Food and Agriculture Organization of the United Nations (FAO). The HQ and CR of local crop ingestion were several orders higher than the safe exposure threshold, mainly for lettuce, chives, and turnips. Our results revealed that inhabitants of the study area are exposed to developing carcinogenic and non-carcinogenic effects due to long-term food consumption with high trace elements. This study sheds light on the need to assess further the quality of agricultural soils and crops grown in mining areas with signs of contamination to guarantee consumer food safety.

Assessing and Understanding Arsenic Contamination in Agricultural Soils and Lake Sediments from Papallacta Rural Parish, Northeastern Ecuador, via Ecotoxicology Factors, for Environmental Embasement

The concentration of arsenic (As), considered a toxic and carcinogenic metalloid, in agricultural soils has become a global challenge. Sources of arsenic in soils can be both anthropogenic and natural. Contaminated water is used for the irrigation of crops and vegetables, and therefore it is the main pathway for arsenic to enter the human food chain, creating a potential health risk. This study evaluated the concentrations of arsenic in agricultural soils in the rural parish of Papallacta, located 67 km east of the city of Quito, Northeastern Ecuador, and constitutes an analysis of the problem of arsenic in agricultural soils. Shallow groundwater and geothermal water discharges laced with arsenic are frequently used for irrigation and have raised the level of arsenic in agricultural soils. This work is focused on evaluating the environmental quality and contamination of agricultural soils through environmental quality indices such as geo-accumulation index, enrichment, and contamination factor. The average arsenic levels in the agricultural soils of the four studied areas fluctuate between 20.4 and 43.0 mg kg−1, while in the sediments of the Papallacta Lake, higher values were found in the range between 16.8 and 102.4 mg kg−1; all of which exceed the permissible limit by the Ecuadorian Environmental Legislation for agricultural use (12 mg kg−1). The results of the study in the five studied sites of the Papallacta civil parish indicate low to moderate levels of arsenic enrichment, soils enriched by bedrock, and moderate to considerable contamination.

Design of Soil Moisture Telemetry System Using cluster-based Wireless Sensor Networks

Agriculture is an art and science used to cultivate the land, grow crops, and raise livestock. Agricultural land in Indonesia has different soil quality in each region. Soil quality for agriculture can have an impact on crops. Therefore, a Wireless Sensor Network (WSN) was created to make it easier to determine soil moisture. This system can help to monitor the condition of soil moisture content. WSN applies a Cluster-Based Algorithm, and the protocol used in WSN is a Low Energy Adaptive Clustering Hierarchy (LEACH). WSN will search for the cluster head, and then the sensor node will send the results of soil moisture sensing data to the cluster head for further data aggregation. Then, the results of the aggregation data will be sent to the sink node and then forwarded to the cloud. Data aggregation can make the sink stay longer than 30 minutes than the sink node that receives data without aggregation. Sink nodes that do not receive aggregation data also use more load current than sinks that receive aggregation data. The test results of the average response time to find new cluster heads have an average time of 6023.4 milliseconds. The maximum distance between nodes to transmit data to each other is 100 meters.

The Effect of Beneficial Autochthonous Microorganisms (Bams) on the Chemical Quality of Agricultural Soils and Olive Production in the Wilaya of Tlemcen (Western of Algeria)

Abstract Beneficial Autochthonous Microorganisms (BAMs) are a multi-purpose technology that has already been used in Latin America and Southeast Asia but is still unknown in Africa and particularly Algeria. The aim is to examine the effect of BAMs on agricultural soils and olive fields. The study was carried out in two degraded olive fields located in the Oued Tafna basin west of Tlemcen (The Semi-arid region in Western Algeria). The objective is to evaluate the effectiveness of BAMs on the chemical characteristics of the soils, particularly in terms of organic matter (MO), pH, electrical conductivity (EC), total limestone (CaCO3), moisture, organic carbon (C) and olive production and its weight. Statistical analysis (Independent Test) between all groups (treated and controls) showed a significant difference, in conductivity (EC) where we recorded “0.214±0.03μs /cm “ in treated soils vs. “0.198±0.029μs/cm “ in control soils a different statistical significance was recorded for the other parameters, however, it was observed that there is a relative increase in these parameters in the soils of the treated groups such as carbon (C): “2.85±1.06%” organic matter (MO): “4.91± 1.83%”, “pH=7.81±0.225”, “CaCO3 27.76±4.99% and a decrease in humidity “15.11±3.77%” compared to control soils. The results of statistical analyses (Mann-Whitney Test and Suite Test) of olive production showed a clear alternation (every other year) in fruit production in the control group and a positive effect of BAMs on olive production in the treated group, with a slight increase of production (19 kg in 2019 vs. 30 kg in 2020), but without any significant difference regarding the weight of the fruit between the two sessions. However, a highly significant difference “p=0.00&lt;0.001” in fruit weight was noted between the treated groups “3.908g” and “5.70g” and the control ones “4.40g “ and “5.00g” in 2019 and 2020 respectively. The use of MAB is an interesting technique to restore the chemical properties of degraded soils, and increase olive tree production. To achieve more reproducible results (in terms of quantity and quality), sufficient doses of these BAMs and periodicals must be added to provide a good nutritional supplement and reduce farmers’ use of pesticides and mineral fertilizers.

Enhancing Soil Quality of Short Rotation Forest Operations Using Biochar and Manure

Biochar and manure may be used to enhance soil quality and productivity for sustainable agriculture and forestry operations. However, the response of surface and belowground wood decomposition (i.e., soil processes) and nutrient flux to soil amendments is unknown, and more site-specific information about soil property responses is also essential. In a split-plot design, the soil was amended with three rates of manure (whole plot; 0, 3, and 9 Mg ha−1) and three rates of biochar (split-plot; 0, 2.5, and 10 Mg ha−1). Soil physical properties, nutrients, and enzyme activities were evaluated in two years. In addition, wood stakes of three species (poplar, triploid Populus tomentosa Carr.; aspen, Populus tremuloides Michx.; and pine, Pinus taeda L.) were installed both horizontally on the soil surface and vertically in the mineral soil to serve as an index of soil abiotic and biotic changes. Wood stake mass loss, nitrogen (N), phosphorus (P), and potassium (K) flux were tested. The high rate of both manure and biochar increased soil water content by an average of 18%, but the increase in total soil P, K, organic carbon (C) content, and enzyme activities were restricted to single sample dates or soil depths. Wood stakes decomposed faster according to stake location (mineral &gt; surface) and species (two Populus &gt; pine). On average, soil amendments significantly increased the mass loss of surface and mineral stakes by 18% and 5%, respectively, and it also altered wood stake nutrient cycling. Overall, the decomposition of standard wood stakes can be a great indicator of soil quality changes, and 10 Mg ha−1 of biochar alone or combined with 9 Mg ha−1 of manure can be used for long-term carbon sequestration in plantations with similar soil conditions to the present study.

Chemical and Biological Properties of Agricultural Soils Located along Communication Routes

The aim of the study was to assess the quality of agricultural soils, which accumulate additional amounts of heavy metals from fertilization and modify their bioavailability, with the use of interdependencies between their biological and chemical properties conditioned by the distance from communication routes. Our results indicated that heavy metals had an impact on enzyme activity in soils and their accumulation was significantly related to the distance from the edge of the road, location of sampling sites, date of soil sampling, and years of research. It was found that the greatest amounts of zinc, cadmium, lead, and copper were accumulated at a distance of 5–20 m from the edge of the road. The highest enrichment factor and geoaccumulation index values were recorded for Pb, followed by Zn, Cu, and Cd. Principal component analysis and regression models showed that the activities of phosphatase and dehydrogenases seem to be the best bioindicators of contamination of roadside soils used for agricultural purposes. Since their activity is related to soil’s organic carbon content, inputs of organic fertilizers and crop residues should be ensured in the agroecosystems along roadsides.

The positive effects of polypropylene and polyvinyl chloride microplastics on agricultural soil quality

The positive effects of polypropylene and polyvinyl chloride microplastics on agricultural soil quality

Bacteroidota structure in the face of varying agricultural practices as an important indicator of soil quality – a culture independent approach

The choice of appropriate agricultural practices has a major impact on soil quality, crop productivity, and bacterial community structure. The aim of our study was to gain insight into Bacteroidota structure, including the phylum, family, and genus in the context of the application of different agricultural practices (crop rotation, intercropping mixture, long-term maize monoculture) across changing seasons (spring, summer, autumn), which is undoubtedly novel among previous reports on different cropping systems. Additionally, the Spearman correlation test as well as ANOVA and RDA statistical analyses were conducted to expand the information on chemical factors directly affecting Bacteroidota abundance in the soil environment. Bacteroidota were shown to be present with varying abundance depending on the agricultural practice and the season. The highest abundance of Bacteroidota occurred when crop rotation was the main agricultural practice, where the highest average yield was also recorded. Thus, our study identified crop rotation as the best of the three agricultural practices compared. The reduction in the relative abundance of Bacteroidota, in particular Flavobacterium sp. in fields K20 (intercropping) and K21 (monoculture), and the achievement of almost twice the lower average yield in field K21 than in field K3, indicated the poorer quality of these soils. We therefore concluded that the increased abundance of Bacteroidota could indicate good quality agricultural soils. It was also proved that the genera Mucilaginibacter and Edaphobaculum are the most sensitive to soil chemistry over the changing seasons, while the genus Flavobacterium is sensitive to agricultural practices and its presence may indicate good quality of agricultural soils. Statistical analyses indicated that chemical properties have a strong influence on Bacteroidota structure formation in agricultural soils. Overall, our results have evidenced that the Bacteroidota community can be an important indicator of soil quality in studies of soil biological degradation processes, since a decrease in the abundance of these beneficial microorganisms potentially could be connected with reduction of the soil quality, fertility and ultimately affects crop yield. They have also shown that the community of this group of bacteria varies between seasons of the year.

Sustainability of Coastal Agriculture in the Face of Soil Degradation: The Influence of Water Salinization as an Example

The pump-irrigated soils of the coastal Chaouia in Morocco are subject to changes in their qualities due to the quality of the irrigation water and their proximity to the sea. This work aims to approach irrigation water quality and the influence of these waters on the quality of agricultural soils. The study is based on the systematic and selective sampling of water and soils (19 water samples and 19 soil samples). Analyzed parameters mainly include the salinity and pH of the soil and water samples. The main results show that soil pH varies from 6.81 to 7.7. However, the pH of the water varies from 6.22 to 8.13. The electrical conductivity in soils varies from 12,260 μs/cm to 700 μs/cm and from 1123 μs/cm to 8120 μs/cm. The results of the analysis of soil salinity show that in moving away from the sea, the salinity decreases, and the salinity of the water samples follows the same trend. The Richard and Wilcox graphs show that most water samples taken near the sea are highly mineralized and have poor water quality. This paper presents important aspects of the feasibility of coastal agriculture and can be a source of inspiration for future research and planning of coastal agriculture.

Efecto de sustratos a base de estiércol de animales sobre la emergencia y el crecimiento vegetativo de avena forrajera (Avena sativa L.)

Oats (Avena sativa L.) are an annual forage grass of great current and potential importance in agricultural development. The objective was to determine the effect of animal manure-based substrates on the emergence and vegetative growth (stem height and leaf length) of forage oats (Avena sativa L.) in relation to organic amendments (chicken-cuy, cattle-sheep, llama-alpaca) over time. Growth variables were measured every ten days up to 60 days. A completely randomised experimental design was used; each treatment consisted of five replicates of ten seeds each. Analysis of variance (ANDEVA), Tukey's multiple comparison and regression and correlation analysis were performed. Both stem height and leaf length were higher when the seeds were established on a substrate based on a mixture of cattle and sheep manure and were lower with the llama-alpaca manure mixture. In general, growth expressed in stem height and leaf length increased over time. The application of organic matter of animal origin improves the quality of agricultural soils, which is reflected in plant growth and development.

Comparison of soil quality indexes calculated by network and principal component analysis for carbonated soils under different uses

There is an urgent need to conserve and improve the quality of agricultural soils in the coming decades. Decision tools capable of providing reliable information about soil quality are needed, and soil quality index (SQI) is one of the most used. Principal component analysis (PCA) is the common methodology to calculate it, however in some cases fails to differentiate soil quality properly. Therefore, the aim of this work is to assess a SQI through a different methodology as network analysis (NTA) and compare it with PCA, assuming that soil uses affect soil qualities differently. From soils with different uses (rainfed, olive grove and forest) network analysis and principal component analysis have been used to select a minimum dataset (MDS) to generate SQI from 36 physical, chemical and biological soil variables. Using NTA, geometric mean of the enzyme activities (GMEAN), bulk density (BD) and phosphatase activity (phos) where selected as indicators, while PCA selected total organic carbon (TOC), free Fe oxides (FeF), crystalline Mn oxides (MnX), pH, electrical conductivity (EC) and percentage of coarse sand (CS). Four SQI were calculated from each MDS through linear and non-linear scoring equations and by additive integration and weights. The SQI generated by NTA were more useful than those generated by PCA, as in addition to having fewer indicators they were able to better differentiate the uses in the study. This greater resolution capacity of the NTA would be the consequence of a better selection of indicators using this method than using PCA.

English

Barriers to successful transfer of contaminated land management policy from one country to another include socio-cultural, economic and environmental differences. While weak contaminated land management regimes desire effective legislation and make efforts to transfer policies from established regimes, contextual differences or characteristics between the two countries involved is a key challenge. These differing characteristics include social values, economic strength, governance structure, and technical know-how. An investigation was conducted through workshop and interviews to determine core social values that are impacted due to contaminated land by oil spills in the Niger Delta region of Nigeria. Workshop was undertaken for participants involving community groups (N=35), while interviews involved contaminated land management regulator (N=8), experts in contaminated land management in the Niger Delta (N=6), and operators in the oil exploration industry (N=7). Water quality, soil quality for agriculture, farming and fishing, and health/wellbeing indicated core social values that influence contaminated land management decisions while stakeholders expressed long-term concern about economic losses, clean-up, environmental degradation and public engagement. It is proposed that policymakers should consider unique conditions and country-specific characteristics in the event of policy adaptation for contaminated land management. An alternative approach to improving contaminated land management is recommended that will account for core social values and accommodate varying perceptions of stakeholders. &nbsp; Key words: Socio-economic values, stakeholder participation, livelihood, drinking water, oil spills, stakeholders&rsquo; perception.

Effect of a Superabsorbent Polymer (Poly-Gamma-Glutamic Acid) on Water and Salt Transport in Saline Soils under the Influence of Multiple Factors.

In order to effectively suppress the negative effects of salt ions contained in saline soils on agricultural soil quality and crop growth, this study took advantage of the water-saving properties and better soil improvement properties of poly-γ-glutamic acid (γ-PGA). By carrying out various experiments, the following relationships have been found. (1) The lab experiment studies the effect of the γ-PGA application on the infiltration of sandy loam soil. The application rates of γ-PGA are 0%, 0.1%, 0.2%, and 0.3%, respectively. (2) HYDRUS-1D is used to simulate water infiltration of sandy loam soil under multiple factors (bulk density, γ-PGA application rate, and the application depth of γ-PGA). (3) The effect of γ-PGA on soil solute (Cl−) transport is also explored in this paper. The results show that bulk density and the application depth of γ-PGA (p < 0.01) have higher effects on cumulative infiltration than the application amount of γ-PGA (p < 0.05). A lower γ-PGA application rate will increase the proportion of unavailable soil water by 3%. The established empirical models have good results. Furthermore, when the γ-PGA application rate is 0.3% (0.02-cm2 min−1), the Cl− hydrodynamic dispersion coefficient is the highest. The study recommends applying the γ-PGA at 1.4 g cm−3, 5–20 cm, and 0.2%. The results of this study are conducive to an in-depth understanding of the physicochemical properties of poly-γ-glutamic acid, improving the utilization rate of salinized land, achieving agricultural water and fertilizer conservation and yield enhancement, and guaranteeing sustainable land use and sustainable development of agroecological environment.