Amelioration Of Saline Soil Research Articles

Effect of salinity stress on the morphological parameters of <i>Hura crepitans</i> L. ameliorated with <i>Calapogonium mucunoides</i> DESV. and Biochar

Salinity is one of the most serious limiting factors for plant growth and production. This study assessed the effect of salinity stress on the morphological parameters of Hura crepitans ameliorated with Calapogonuim mucunoides Desv. and Biochar. Standard methodology was adopted to examine physicochemical properties of the soil and morphological parameters of the plant. The physicochemicalproperties of the experimental soils was significant at p=0.01. Morphological parameters of shoot length of H. crepitans at 1% non-amended saline soil for week 6 and 7 recorded 4.03±4.03cm which indicated a significant reduction (p=0.01) when compared to control 15.70±3.35 and 19.50±4.43cm respectively. The amelioration of the saline soil at 0.001% KI with biochar and C. mucunoides (21.80±0.05 and 22.43±3.52cm) of H. crepitans shoot length was significant when compared to the control 21.00±4.00cm. The higher the concentration of salinity, the lower the petiole length of H. crepitans for amended treatments. The photosynthetic pigment 56.70±2.47 of H .crepitans at 0.001% was significant (p=0.05) when compared to the control 51.36±2.99.This results showed that salinity causes a detrimental effect on some plant growth parameters. However, amelioration of saline soil with C. mucunoides and biochar recorded a satisfactory remediation effect on the growth of H. crepitans. Based on this research, amelioration treatment such as C. mucunoides and biochar can be use to improve crops planted in saline soil.

Effects of soil conditioners on vineyard saline soil physicochemical properties and bacterial community in arid areas

AbstractSoil salinization adversely affects soil quality and ecosystem. Many researches have tried to ameliorate saline soils by soil conditioners. However, little is known about the differences in the responses of soil bacterial communities to natural and artificial conditioners applied to saline soils. Therefore, in this study, the effects of natural humic acid (IK), synthetic polymer (IP), and composite material (IF) (mixture of IK and IP (1:1)) on bacterial community structure and functional genes in saline soil were evaluated to clarify their differences. The results showed that the application of the three soil conditioners significantly reduced soil pH and Na+ content but increased soil alkaline phosphatase, urease, invertase and catalase activities, bacterial diversity, and nutrients, compared to the control (no conditioner). IK application increased bacterial relative abundance (e.g., Subgroup_6, RB41, MND1, and KD4‐96) and metabolic functions (e.g., Two‐component system and Biosynthesis of amino acids) by increasing soil nitrogen and maintaining K+ and Na+ balance. IP application increased soil alkaline phosphatase and urease activities as well as bacterial relative abundance (e.g., Subgroup_6, RB41, MND1, Gemmatimonadaceae, and KD4‐96) and metabolic functions (e.g., Quorum sensing and carbon metabolism) by increasing soil organic carbon/nitrogen content. IF application increased the bacterial relative abundance of Subgroup_6, RB41, and MND1 by increasing soil available nitrogen and regulated their metabolic pathways (e.g., ABC transporters and microbial metabolism). On the whole, IK, IP, and IF could regulate the structure and function of soil bacterial community in saline soils. This study clarifies difference in the effects of different soil conditioners on the amelioration of saline soils from the perspective of soil microbiology, and provides a reference for the amelioration of saline soils in arid areas.

Soil health improvement by inoculation of indigenous microalgae in saline soil.

Using biological methods to improve saline soils is recognized as an eco-friendly and sustainable way. In this study, two indigenous algae YJ-1 and YJ-2 screened from salinized farmland were inoculated into saline soils with different salinization levels to investigate their potential in enhancing soil health by laboratory microcosm experiment. The results showed that individual inoculation of the two algae quickly resulted in the formation of algal crusts, and the chlorophyll content in the saline soils gradually increased with the incubation time. The soil pH decreased significantly from the initial 8.15-9.45 to 6.97-7.56 after 60-day incubation. The exopolysaccharides secretion and the activities of catalase, sucrase, and urease in saline soils also increased. Microalgal inoculation increased soil organic matter storage, while decreasing the available nutrient contents possibly due to the depletion of microalgal growth. PCA and PCC results identified that microalgal biomass as the predominant variable affecting soil quality. Overall, these data revealed the great potential of microalgae in the amelioration of saline soils, especially in pH reduction and enzyme activity enhancement. This study will provide the theoretical foundation for improving saline soils via algalization.

Assessment of the effectiveness of methods for reducing soil salinization based on experimental data for Uzbekistan

The article briefly analyzes foreign approaches to regulating the salt regime of soils and compares them with leaching methods used in Uzbekistan. Based on experimental data from the authors’ field studies, a comparison was made of the effectiveness of check leaching and alternative methods of soil desalinization for the conditions of Uzbekistan. The purpose of this study is to find a method for amelioration of saline soils with economical use of water, taking into account the scarcity of water resources. The materials can serve as a guide for choosing technology for regulating the salt regime of the kidney in various conditions and situations.

Improving the monitoring of root zone soil salinity under vegetation cover conditions by combining canopy spectral information and crop growth parameters.

Soil salinization is one of the main causes of land degradation in arid and semi-arid areas. Timely and accurate monitoring of soil salinity in different areas is a prerequisite for amelioration. Hyperspectral technology has been widely used in soil salinity monitoring due to its high efficiency and rapidity. However, vegetation cover is an inevitable interference in the direct acquisition of soil spectra during crop growth period, which greatly limits the monitoring of soil salinity by remote sensing. Due to high soil salinity could lead to difficulty in plants' water absorption, and inhibit plant dry matter accumulation, a method for monitoring root zone soil salinity by combining vegetation canopy spectral information and crop aboveground growth parameters was proposed in this study. The canopy spectral information was acquired by a spectroradiometer, and then variable importance in projection (VIP), competitive adaptive reweighted sampling (CARS), and random frog algorithm (RFA) were used to extract the salinity spectral features in cotton canopy spectrum. The extracted features were then used to estimate root zone soil salinity in cotton field by combining with cotton plant height, aboveground biomass, and shoot water content. The results showed that there was a negative correlation between plant height/aboveground biomass/shoot water content and soil salinity in 0-20, 0-40, and 0-60 cm soil layers at different growth stages of cotton. Spectral feature selection by the three methods all improved the prediction accuracy of soil salinity, especially CARS. The prediction accuracy based on the combination of spectral features and cotton growth parameters was significantly higher than that based on only spectral features, with R2 increasing by 10.01%, 18.35%, and 29.90% for the 0-20, 0-40, and 0-60 cm soil layer, respectively. The model constructed based on the first derivative spectral preprocessing, spectral feature selection by CARS, cotton plant height, and shoot water content had the highest accuracy for each soil layer, with R2 of 0.715,0.769, and 0.742 for the 0-20, 0-40, 0-60 cm soil layer, respectively. Therefore, the method by combining cotton canopy hyperspectral data and plant growth parameters could significantly improve the prediction accuracy of root zone soil salinity under vegetation cover conditions. This is of great significance for the amelioration of saline soil in salinized farmlands arid areas.

Soil Salinity Estimation in Cotton Fields in Arid Regions Based on Multi-Granularity Spectral Segmentation (MGSS)

Soil salinization seriously threatens agricultural production and ecological environments in arid areas. The accurate and rapid monitoring of soil salinity and its spatial variability is of great significance for the amelioration of saline soils. In this study, 191 soil samples were collected from cotton fields in southern Xinjiang, China, to obtain spectral reflectance and electrical conductivity (EC) indoors. Then, multi-granularity spectral segmentation (MGSS) and seven conventional spectral preprocessing methods were employed to preprocess the spectral data, followed by the construction of partial least squares regression (PLSR) models for soil EC estimation. Finally, the performance of the models was compared. The results showed that compared with conventional spectral preprocessing methods, MGSS could greatly improve the correlation between spectrum and soil EC, extract the weak spectral information of soil EC, and expand the spectral utilization range. The model validation results showed that the PLSR model based on the second-order derivative (2nd-der-PLSR) had the highest estimation accuracy among the models constructed by conventional methods. However, the PLSR model based on MGSS (MGSS-PLSR) had the highest estimation accuracy among all models, with Rp2 (0.901) and RPD (3.080) being 0.151 and 1.302 higher than those of the 2nd-der-PLSR model, respectively, and nRMSEP (5.857%) being 4.29% lower than that of the 2nd-der-PLSR model. The reason for the high accuracy of the MGSS-PLSR model is as follows: In the continuous segmentation of the raw spectrum by MGSS, the bands with strong and weak correlations with respect to soil EC were concentrated during low granularity segmentation. With the increase in granularity level, the spectral features decreased and were distributed discretely. In addition, the locations of spectral features were also different at different granularity levels. Therefore, the spectral features of soil EC can be effectively extracted by the MGSS, which significantly improves the spectral estimation accuracy of soil salinity. This study provides a new technical means for soil salinity estimation in arid areas.

Ameliorating Effect of Organic Materials on Saline-Sodic Soil in Central Ganga Plain in Uttar Pradesh, India

ABSTRACT Field experiments were conducted for two years to evaluate the ameliorating effect of locally available diverse organic materials on saline sodic soil. The treatments comprised no-amendment (control), 100% GR (16.2 t ha−1), vermicompost, spent mushroom compost of Pleurotus ostreatus, farm yard manure, sheep dung and green manure (Prosopis julifera) each applied @ 10 t ha−1. Compared to 100% GR, the pooled EC reduced for two treatments spent mushroom compost and sheep dung (by 45 and 19%, respectively) while it was comparable (slight increased by 1.5%) for vermicompost. In 2019, soil pH for vermicompost and sheep dung was significantly on par with 100% GR, although this trend was insignificant in 2020. It can be concluded that vermicompost and sheep dung can be used in amelioration of sodic and saline sodic soil, respectively, and mushroom compost followed by natural leaching can be used in amelioration of saline soils.

A Root Density Tradeoff in an Okra-Assisted Subsurface Pipe Drainage System for Amelioration of Saline Soil

Subsurface pipe drainage technology can effectively improve coastal saline land in Northern China. We explored an okra (Abelmoschus esculentus L.)-assisted subsurface pipe drainage system to improve the water and salt discharge performance and benefits. In this study, the simulation box experiment was conducted to research the response of water and salt discharge performance in subsurface pipe drainage to okra root weight density (RWD). The drain outflow, soil salinity, and sodium adsorption ratio were determined. The results showed that okra RWD affected the vertical distribution of okra roots. Okra with an appropriate RWD (about 116 μg·cm−3) could significantly increase the cumulative drain outflow. Okra with an appropriate RWD (about 136 μg·cm−3) could significantly increase the desalting effect. Moreover, the RWD of okra also influenced the ability of subsurface pipe drainage to inhibit soil alkalization. The above results show that planting okra and installing subsurface pipe drainage to control drainage at the coastal saline land in Northern China can effectively improve the water and salt drainage effect when okra RWD is about 116–136 μg·cm−3. When using subsurface pipe drainage to improve coastal saline soils, planting okra with proper density may be an appropriate choice to improve the effect and benefit.

Ion dynamics in post harvest saline soil influenced by organic amendment and moisture level

Organic amendments might be effective and sustainable in the amelioration of saline soil if proper management put in place. Accordingly, subsequent pot and field experiments were conducted in a saline soil to determine the effects of moisture levels and organic amendments on cation exchange capacity (CEC), ion dynamics under rice cultivation. The increment of CEC of the studied post harvest soils was significant, except for the moist condition under field experiment. There were significant variations in ion dynamics among the treatments under both the experiments at saturated soil conditions. Exchangeable Na+ contents decreased and K+ contents increased significantly with the increased rates of treatments. Exchangeable Ca2+ and Mg2+ contents of soil followed almost the similar trends as that exhibited by K+ but not significant. Among the anions, chloride decreased significantly under both the experiments while sulfate and bicarbonate contents increased by the applied treatments. This might be due to the inherent consequences of organic amendments on these soil properties. Bangladesh J. Sci. Ind. Res.56(3), 185-194, 2021

Rehabilitation of saline soil with biogas digestate, humic acid, calcium humate and their amalgamations

ABSTRACT Amelioration of saline soil is a requisite in order to increase crop productivity. A soil incubation study was performed for 60 days using digestate, humic acid, calcium humate and their combinations to investigate the influence on physical, chemical, microbial and enzyme activities of saline soil. Overall, digestate combined with calcium humate followed by humic acid treatments have shown their potency in decreasing the soil pH, electrical conductivity (EC), and sodium ion (Na+) concentration, and increase in potassium ion (K +), calcium ion (Ca 2+), magnesium ion (Mg 2+), mean weight diameter (MWD), soil enzyme activities, microbial biomass carbon (MBC), MBC: microbial biomass nitrogen (MBN) and soil respiration than control. The digestate, humic acid individually and their amalgamation evidenced greater MBN among all the treatments. The digestate alone efficiently improved the soil properties than humic acid and calcium humate individual groups except for the MWD where it is pronounced more in the latter groups. The greater metabolic quotient (qCO2) was observed in control than organic matter amended treatments indicating the stress conditions. The increase in water-extractable organic matter (WEOM) with minimal aromaticity (specific ultraviolet absorbance at 254 nm-Suva 254) in integrated amendments comprising groups, laid the ground reason to improve the properties of saline soil. Therefore, this study concludes that the fusion of fresh and humified substrates could facilitate reclamation.

Contrasting effects of corn straw biochar on soil water infiltration and retention at tilled and compacted bulk densities in the Yellow River Delta

During field application of biochar, the bulk density of tilled soil initially decreases and then increases over time, until reaching the initial level of compacted soil. This study evaluated the optimal biochar particle size for promotion of water infiltration and retention in a saline soil with various bulk densities after application. Corn straw biochar, pyrolyzed at 450 °C for 0.5 h, was prepared in different particle sizes (S1 ≤ 0.25 mm, S2 = 0.25–1 mm, and S3 = 1–2 mm) and separately mixed into the 0–30 cm soil layer at two rates (R1 = 10 g kg−1 and R2 = 100 g kg−1), with tilled (D1 = 1.1–1.43 g cm−3) and compacted (D2 = 1.45 g cm−3) bulk densities. Five models were applied to simulate water infiltration into biochar-amended soils. Compared with the non-biochar control, the S1 treatment increased cumulative water infiltration by 41% (bulk density = 1.26 g cm−3) to 11% (bulk density = 1.45 g cm−3). However, the effect of the S3 treatment on cumulative water infiltration shifted from positive (+19.3%) to negative (–22.4%) with increasing bulk density. The S2 treatment resulted in the highest water retention at the tilled bulk density, whereas a significant increase (12.7%) in water retention was observed in the S1 treatment at the compacted bulk density. The Kostiakov–Lewis, Kostiakov, and United States Department of Agriculture – Natural Resources Conservation Service models performed better than the Philip and Horton models to describe the relationship between cumulative water infiltration and infiltration time, except for the D2R2S1 treatment. This study provides evidence for amelioration of saline soil by straw biochar in the Yellow River Delta.

Effect of organic amendments on soil salinity and the growth of maize (Zea mays L.)

Soil salinity is a major concern in southwestern part of Bangladesh because almost 30% cultivable lands are currently lying under risk of salinity where 30-50% yields loss is happening. Organic amendments have found to be effective in the amelioration of saline soil by improving soil physical and chemical properties as well as crop selection is another criteria for sustaining viability of crops in saline soil. For ensuring sustainable saline soil management, a comparative pot study was carried out during kharif 1 season in 2015 to observe the effect of organic amendments (solid waste, vermicompost and cow dung) on soil salinity and its influence on the growth of maize. Composite soil was collected at a depth of 0-15 cm from Gozalmari village of Jalma Union in Batiaghata Upazila under Khulna district, Bangladesh that was saline (10.6 dS/m) in nature and the irrigation water sample was collected from beside Kazibacha river (4.28 dS/m) that was also moderately saline. The maize cultivar “Shuvra” was used for cultivation in the study. The experiment comprised of four treatments viz. T0: Control (No organic manure); T1: Solid waste (36g); T2: Vemicompost (72g); T3: Cow dung (33g). Five seeds were sown in each pot. Seeds were treated with Agrosan GN to protect them from seed and soil borne pathogens. Chemical fertilizers were not used in the experiment. Irrigation was done two times before harvesting: at 20 days after sowing (DAS) and at 40 DAS with river water and rain water was irrigated naturally during the season. Findings were that the organic amendments significantly influence the physico-chemical properties of the saline soil. All organic treated soils significantly reduce the soil EC (from 10.6 dS/m to 3.4 dS/m) and pH (from 7.63 to 7.38) compared to control soil (p?0.05). In case of survival parameters (e.g %gemination, rate of survival at 50 DAS) of maize, the treatments were found insignificant (p?0.05). But in terms of growth parameter (plant height and root length), significant differences were found between control and organic amendments treated soil (p?0.05). It may be concluded that organic amendments treated soils showed better results than that of control soil. If proper management can be implemented, this positive results will bring hope to the local poor farmers at least can introduce a new crop in fallow agricultural land during the kharif 1 season.

Amelioration of Saline Soil by the Application of Gypsum, Calcium Chloride, Rice Husk and Cow Dung

A pot experiment was conducted to investigate the effect of cow dung, rice husks, calcium chloride and gypsum on soil reclamation and compare the effect of organic and inorganic amendments on soil reclamation during the period of 5th March to 20th April, 2017. The experiment was laid to fit a completely randomized design (CRD) with seven treatments [Reference soil (T0), Cow dung (T1), Rice husk (T2), Gypsum (T3), Calcium chloride (T4), Cow dung + Rice husk (T5) and Gypsum + Calcium chloride (T6)] each having three replications for this experiment. After incubation (45 days), the laboratory investigation was carried out in the Soil, Water and Environment Discipline, Khulna University, Khulna, Bangladesh. Results indicate that the individual or combined effect of gypsum (T3) was more effective in changing EC and SAR. Gypsum application in combination with calcium chloride (T6) improved the soil chemical properties by reducing the EC. Among the treatment, calcium chloride (T4) had a remarkable effect in reducing sodium adsorption ratio and gypsum had a remarkable effect in reducing pH. Cow dung (T1), rice husk (T2), combination of cow dung and rice husk (T5) were less effective to reduce EC, pH and SAR. It’s measured for soils of different soil amendments varied significantly (P

Multiple additions of rapidly decomposable residue alleviate the negative impact of salinity on microbial activity

In previous research, we found that the reduction in soil respiration with increasing salinity was smaller in soils amended with rapidly decomposable residues (low C:N ratio) compared with slowly decomposable residues (high C:N ratio). However, with a single residue addition, available organic carbon will be quickly decomposed until only recalcitrant compounds remain. A more consistent supply of residues may improve the tolerance of microbes to salinity, but this effect could depend on residue decomposability. A 56-day incubation experiment was conducted with four loam soils having electrical conductivity (EC1:5) of 0.1, 1, 2.7 and 3.7dSm–1 amended 1–4 times with finely ground slowly decomposable canola (C:N=82) and rapidly decomposable kikuyu residues (C:N=19) with a total addition of 10gCkg–1 soil. There was a greater reduction in soil respiration with increasing salinity following addition of canola than addition of kikuyu. At all salinity levels and with both residues, cumulative respiration two weeks after addition of 10gCkg–1 was higher with multiple additions than with a single addition. The reduction of cumulative respiration with increasing salinity was smaller with repeated addition of rapidly decomposable residue than with only a single addition. However, this was not the case with slowly decomposable residue. The results suggest that for amelioration of saline soils, addition of rapidly decomposable residue is more effective than adding slowly decomposable residues, particularly when rapidly decomposable residues are added repeatedly.

Influence of Rice Straw Incorporation on the Microbial Biomass and Activity in Coastal Saline Soils of Bangladesh

Coastal soils of Bangladesh are affected by salinity. This study investigated salinity as a stress factor on coastal soils in Bangladesh. It was also observed if incorporation of rice straw could remediate negative impacts of soil salinity (if any) on microbial activ-ity. The microbial biomass carbon ranged from 137.85 to 614.88 μg/g among the soils (n = 11). Microbial biomass carbon content and number of both cultivable bacteria and fungi decreased in the soils with higher ECes (electrical conductivity). Respiration was measured over 30 days with each soil pre incubated at 50% of water holding capacity. Basal respiration rate as well as soil organic carbon content (r = 0.88, p - 37.73 mS/cm) (12.91 - 16.89 mg CO2/g dry soil) than in the nonsaline soils (0.98 - 2.33 mS/cm) (5.79 - 6.51 mg CO2/g dry soil). Application of rice straw at 0.50%, 1.00%, 1.50% and 2.00% reduced the negative impact of soil salinity especially at higher ECes (6.63 - 37.73 mS/cm). Application of 1.00% rice straw appeared to be acceptable for successful amelioration of saline soils of the study area.

Agroforestry and its application in amelioration of saline soils in eastern China coastal region

Some environmental problems, especially soil salinity hinder the regional sustainable development of eastern China coastal region. Salinity mainly comes from tide weave, seawater flooding and seawater intrusion. Over exploitation of groundwater, which is the result of unfitful land use systems, leads to seawater intrusion and salt concentration increase. Agroforestry systems can enrich soil fertility and prevent soil salinization, furthermore help maintain biodiversity and enhance productivity. For the intergrated multiple ecosystems the most critical issue is to select optimum tree species and rationally arrange these plants. The basics of this multiple ecosystem is that different plants will occupy variable ecological niches within an area, both in space and in soil depth. Shelterbelts and trees intercropping with agricultural crops are major types of the multiple ecosystem. Shelterbelts can reduce wind speed and consequently lessen evaporation and erosion of the soil, increase pasture growth by up to 60% on exposed sites, increase crop yields by up to 25%. Besides intercropping with jujube, other agroforestry multiple ecosystem such as forestry plus agriculture, forestry plus agriculture plus fishery, and forestry plus animal husbandry are the most appropriate ways to utilise land resource in this region.