Amelioration Of Saline-sodic Soil Research Articles

Assessing the efficacy of ameliorants on saline-sodic soils: Laboratory insights for reclamation strategies

This study presents the combined findings of laboratory experiments conducted to assess the efficacy of various ameliorants on saline-sodic soils in the foothill plain of Ile Alatau in the Northern Tianshan region. The investigation focused on the influence of phosphogypsum, elemental sulfur, nano sulfur, and sulfuric acid on the ionic composition of the soil solution and their impact on the soil-absorbing complex. Different doses of these ameliorants were applied to saline-sodic soil samples, and their incubation period was observed. The analysis of the aqueous extract of the soil emphasized the presence of bicarbonate, carbonate, sulfate, calcium, and sodium ions. The results revealed that sulfuric acid was the most effective ameliorant, rapidly neutralizing extreme alkalinity, reducing bicarbonate and carbonate ion content, and increasing sulfate and sodium ion concentrations. Elemental sulfur ranked second in effectiveness, significantly decreasing bicarbonate and carbonate ions and increasing sulfate and sodium ions. Phosphogypsum exhibited the lowest effectiveness, causing reductions in bicarbonate and carbonate ions and modest increases in sulfate and calcium ions. The study demonstrated that the introduction of phosphogypsum led to an increase in calcium and sulfate ions in the soil solution, while elemental sulfur and sulfuric acid significantly increased the sulfate ion content. Sulfuric acid exhibited the highest efficacy among the ameliorants, completely neutralizing normal carbonates and reducing alkalinity in the soil solution. The formation of subsoil gypsum through the interaction of sulfuric acid with calcium carbonates facilitated the displacement of sodium from the soil-absorbing complex. These findings contribute to our understanding of the processes involved in the amelioration of saline-sodic soils and provide insights into effective soil management practices. They serve as a theoretical basis for developing strategies for the reclamation of such soils worldwide. The research highlights sulfuric acid as the most effective ameliorant for saline-sodic soils, resulting in a significant rearrangement of the soil's ionic composition. Further research and field studies are necessary to validate and refine these laboratory findings for practical applications in soil improvement methods.

Influence of environmental-friendly bio-organic ameliorants on abiotic stress to sustainable agriculture in arid regions: A long term greenhouse study in northwestern Egypt

The problem of soil salinity is rapidly increasing, with more than 950 million hectares affected by salinity stress (Arora et al., 2017). The amelioration of saline-sodic soils using chemical ameliorates could increase CO2 emissions and soil degradation. Therefore, amending saline-sodic soil with environmentally friendly bio-organic ameliorants such as brewer's spent grain (SG) and Azospirillum (A. brasilense) bacteria could represent a safe and cheaper approach compared to other organic (compost; CT) and mineral fertilizers. Under greenhouse conditions, maize was grown in saline-sodic soil amended with bio-organic ameliorants. Nine treatments were included; (i) SG1 (23.8 t ha−1); (ii) SG2 (47.6 t ha−1); (iii) TC1 (23.8 t ha−1); (iv) TC2 (47.6 t ha−1); (v) injection of A. brasilense with corn seeds (Az); (vi) combination of A. brasilense and SG (Az + SG1); (vii) combination of A. brasilense and compost (Az + TC1); (viii) mineral fertilizers (NPK) and (ix) the control (CK). The results revealed that soil amended with Az and SG2 significantly decreased the exchangeable sodium percentage (ESP) and higher cation exchange capacity (CEC). Compared with the control, the exchangeable sodium (Ex-Na+) concentration was decreased by 53.2 and 49.27%, for Az and Az + SG1 treatments, respectively. The fresh- and dry weight observed for Az + SG1, SG2, and Az treatments were increased compared to TC1, TC2, NPK, and CK treatments. The grain and biological yields were higher in Az + SG1 and SG2 than in TC2, NPK ameliorants, and CK. The bio-organic ameliorants alleviated the abiotic stress, enhance the growth and productivity of corn plants, decrease soil ESP and Na+ content, and enhance soil fertility. In conclusion, the application of SG2 can enhance the growth, and productivity of maize grown under salinity-sodicity stress. Therefore, SG2 and Az + SG1 are recommended for direct application in saline-sodic soil.

Salinity fractionation of saline-sodic soils reclaimed by CaCl2-amended brackish ice

The amelioration of saline-sodic soil and the rational utilization of irrigation water resources are important environmental problems worldwide, particularly in the arid and semi-arid regions. In order to study the water-salt dynamics and reclamation effects of CaCl2-amended brackish ice on saline-sodic soils, we conducted a laboratory experiment to study the salinity fractionation of brackish ice and the amelioration effects in different saline-sodic soils (ESP 20, 40, and 70) under four salinity levels (1, 1.6, 2.2, and 2.8 g/L) of brackish ice. Based on the analysis of soil pH, electrical conductivity (EC), sodium adsorption ratio (SAR), alkalinity, infiltration depth, and ionome, the results showed that the pH, SAR, and alkalinity of ESP 20 soil with a higher salinity (2.2 g/L, Na/Ca ≤ 1.14) of brackish ice could be improved. However, for high ESP soils (ESP 40 and 70), there was no significant difference among brackish ice treatments of 1, 1.6, 2.2, and 2.8 g/L, the 0–12 cm soil layer could be desalted, but more salts accumulated at the lower layer of the soil profile. We further determined an optimal brackish ice concentration to improve different ESP soils: 2.2 g/L brackish ice for ESP 20 soil, 1.6 g/L for ESP 40 soil, and 1 g/L for ESP 70 soil. CaCl2-amended brackish ice can be used to ameliorate saline-sodic soil, this study provides invaluable supporting information on saline-sodic soil reclamation by optimizing brackish ice salinity and sodicity.

Reclamation and amelioration of saline-sodic soil using gypsum and halophytic grasses: Case of Golina-Addisalem irrigation scheme, Raya Kobo Valley, Ethiopia

In Golina-Adisalem irrigation scheme, 500 ha becoming salt-affected. Rehabilitation of salt-affected fields using drainage is expensive and leaching by far not feasible in shallow water table areas...

Use of a stabilized sewage sludge in combination with gypsum to improve saline-sodic soil properties leached by recycled wastewater under freeze-thaw conditions

Soil salinization is a major environmental hazard that limits agricultural production. Using sewage sludge and recycled wastewaters in amelioration of saline-sodic soils is one of the most effective ways to dispose waste. However, a very low initial permeability of soil in the freeze-thaw conditions can make improvement difficult. Therefore, column experiments at a soil depth of 15 cm have been conducted to determine the effects of the combination of four stabilized sewage sludge doses (0, 50, 100, 150 t ha−1), three freeze-thaw cycles (0, 5, 10 times) and two water types (FW: freshwater, RWW: recycled wastewater) on gypsum-treated saline-sodic soil properties. The effects of non-saline-sodic RWW on the soil properties were similar to the FW in total 22.5 cm leaching amount. Compared to gypsum alone and initial values, sewage sludge increased wet aggregate stability, organic matter, total N and exchangeable Ca + Mg while it decreased pH, exchangeable Na and CaCO3. Saturated hydraulic conductivity was not induced by sewage sludge although exchangeable sodium percentage and electrical conductivity were reduced by 44% and 63.6%, respectively. Negative effects of freeze-thaws on hydraulic conductivity and salinity and sodicity elimination were not observed, while pH and aggregate stability were negatively affected from ten freeze-thaws. Overall, it can be concluded that the improvement of hydraulic conductivity is attributed to the further improvement of soil structure from more strong wet aggregate stability via additional sewage sludge and leaching amounts.

Utilization of Bio-Municipal Solid Waste Improves Saline-Sodic Soils and Crop Productivity in Rice-Wheat

Solid waste management and soil degradation are the two main issues faced by the developing countries. The present study is the first effort to use bio-municipal solid waste (MSW) for the amelioration of saline-sodic soils of Pakistan. A pot experiment was conducted to evaluate the effects of MSW, farm yard manure (FM) and gypsum application on nitrate leaching, soil physicochemical characteristics and crop productivity under rice-wheat cropping system. The MSW was aerobically composted alone (MSW compost) or with FM (MSW_manure compost) or buried underground in lined pit for anaerobic decomposition (buried MSW) . Maximum nitrate leaching was observed during rice (84.91 mg L−1) and wheat (46.18 mg L−1) with buried MSW as compared with control treatment. Results showed that buried MSW significantly (p < 0.05) lowered the soil pHs (-5.6%), electrical conductivity (-38.8%), calcium carbonate (-45.8%), and sodium adsorption ratio (-51.4%) and significantly increased the organic matter (86.3%) and cation exchange capacity (31.50%) as compared with control treatment. Path analysis showed the highest direct path coefficient during rice and the lowest one during wheat. Soil amelioration with organic amendments was further confirmed with multivariate analysis. This study has proved that buried MSW can be used as an effective solution for MSW disposal thereby improving soil physicochemical properties and crop productivity from saline-sodic soil.

Reclamation of two saline-sodic soils by the combined use of vinegar residue and silicon-potash fertiliser

Amelioration of saline-sodic soil is essential to increase crop production and preserve the ecological environment in arid and semiarid regions. In this study, a pot experiment was conducted to investigate the effect of combined use of vinegar residue and silicon-potash (Si-K) fertiliser on the physical and chemical properties of two calcareous saline-sodic soils (saline soil (H-soil) and saline-sodic soil (S-soil)) and the growth of oat plants. The results showed that soil electrical conductivity was significantly decreased when vinegar residue was applied in two soils, which could be attributed to that vinegar residue could release H+, and react with HCO3−. When the combination of vinegar residue and Si-K fertiliser were used, equilibrium condition between monovalent cations and divalent cations could be altered. The divalent cations (e.g. Ca2+, Mg2+) were adsorbed at the cost of monovalent cations (Na+), resulting in the reduction of sodium adsorption ratio in the two soils. The decrease in soil pH was mainly due to the decrease in the activity of CO32− and HCO3−, which would react with H+ while vinegar residue was applied. As a saline-sodic soil, S-soil exhibited larger decrease in the pH compared with H-soil, a saline soil. The increase in the relative weight of wet stable macro-aggregate could be attributed to the release of Ca2+ and H+ and the flocculation of the dispersed clay by the application of Si-K fertiliser and vinegar residue. The application of Si-K fertiliser and vinegar residue contributed to a significant increase in survival rate and plant height of oat plants. It also led to increased relative water content and reduced electrolyte leakage for oat plants. This could be ascribed to the improvement of soil aggregate structure and nutrient supply, which promoted selective absorption and transportation of K+ over Na+ and decreased leaf damage. Therefore, the combined use of vinegar residue and Si-K fertiliser was considered to be a wise method for ameliorating two calcareous saline-sodic soils in Shanxi Province, Northern China.

A Comparative Study of Different Amendments on Amelioration of Saline-Sodic Soils Irrigated with Water Having Different EC: SAR Ratios

ABSTRACTSoil degradation affects soil properties such as structure, water retention, porosity, electrical conductivity (EC), sodium adsorption ratio (SAR), and soil flora and fauna. This study was conducted to evaluate the response of contrasting textured soils irrigated with water having different EC:SAR ratios along with amendments: gypsum (G), farm manure (FM), and mulch (M). Water of different qualities viz. EC 0.6 + SAR 6, EC 1.0 + SAR 12, EC 2.0 + SAR 18, and EC 4.0 + SAR 30 was used in different textured soils with G at 100% soil gypsum requirement, FM at 10 Mg ha−1, and M as wheat straw was added on surface soil at 10 Mg ha−1. Results revealed that the applied amendments in soils significantly decreased pHs and electrical conductivity (ECe) of saturated paste and SAR. Four pore volumes of applied water with leaching fraction 0.75, 0.77, and 0.78 removed salts 3008, 4965, and 5048 kg ha−1 in loamy sand, silty clay loam, and sandy clay loam soils, respectively. First four irrigations with LF of 0.82, 0.79, 0.75, and 0.71, removed 5682, 5000, 3967, and 2941 kg ha−1 salts, respectively. The decreasing order for salt removal with amendments was FM > G > M > C with LF = 0.85, 0.84, 0.71, and 0.68, respectively. This study highlights a potential role of soil textures to initiate any mega program for reclamation of saline-sodic soils in the perspective of national development strategies.

Comparative effects of different soil amendments on amelioration of saline-sodic soils

&amp;nbsp; A greenhouse experiment was conducted to test the potential of different soil amendments in saline-sodic soils reclamation; to affect the growth response of alfalfa (Medicago sativa L.) plants grown on two saline-sodic soils; and to evaluate the comparative efficiency of different soil amendments for their effects on salinity, sodicity, and pH&amp;nbsp;levels of the soils. To achieve these objectives, two highly saline-sodic soils were selected (Abees, Typic torrifluvents and Elhammam, Typic calciorthids). Different soil amendments were used (compost, anthracite coal powder, water treatment residuals, ferrous sulphate, and a combination of them). The results of the study indicated that pH of Elhammam soil was less affected than pH of Abees soil after the amendment application because of the high calcium carbonate content which acted as a buffer and resisted any appreciable change in soil pH in the alkaline range. The positive effects of all treatments followed the order: T16 &amp;gt; T12 &amp;gt; T13 &amp;gt; T14 = T5 &amp;gt; T11 = T15 &amp;gt; T7 &amp;gt; T8 &amp;gt; T4 = T6 &amp;gt; T9 = T10 &amp;gt; T2 &amp;gt;T3&amp;gt; T1 &amp;gt;T0. The most effective amendment in reducing SAR&lt;sub&gt;e &lt;/sub&gt;in the experimental soils was T16. This was due to the presence of Al in WTRs and Fe in ferrous sulphate which enhanced the leaching process, and the presence of high adsorptive capacity materials like WTRs and compost which adsorb more sodium. The positive effects of all treatments for reducing SAR&lt;sub&gt;e&lt;/sub&gt; in Abees soil followed the order: T16 &amp;gt; T15 &amp;gt; T14 &amp;gt; T13 &amp;gt; T11 &amp;gt; T12 .While, in Elhammam soil, the order was: T16 &amp;gt; T15 &amp;gt; T14 &amp;gt; T13 = T11&amp;gt;T12 = T5. The removal sodium efficiency (RSE) or percentage of Na-removed from the soils at the end of the experiment was significantly reduced after the application of the amendments. RSE of T16 proved the highest value (76%) among the treatments for the two soils used, followed by T15 and T14. The yield of biomass at T16 significantly increased, the increase being 959% in comparison with T0 in Abees soil, while the increase in biomass yield was 1452% in comparison with T0 in Elhammam soil. However, field tests are necessary to draw the final conclusions.

Amelioration of Saline-Sodic Soils with Tillage Implements and Sulfuric Acid Application

Amelioration of saline-sodic soils through land preparation with three tillage implements (disc plow, rotavator and cultivator) each followed by application of sulfuric acid at 20% of gypsum (CaSO 4·2H 2O) requirement or no sulfuric acid application during crop growth period was evaluated in a field study for 2.5 years at three sites, i.e., Jhottianwala, Gabrika (Thabal), and Thatta Langar, in Tehsil Pindi Bhattian, Hafizabad District, Pakistan. Within 2.5 years, there was a decrease in the salinity parameters measured (electrical conductivity, pH, and sodium adsorption ratio), with a gradual increase in rice and wheat grain yields. It was observed that the disc plow, which not only ensured favorable yields but also helped improve soil health at all the three sites, was the most effective tillage implement. Also, application of sulfuric acid resulted in higher yields and promoted rapid amelioration of the saline-sodic soils.

Amelioration of saline–sodic soil with mildly saline water in the Songnen Plain, northeast China

Abstract. The saline–sodic soils of the dryland Songnen Plain in northeast China are only slowly permeable to fresh water because of their large content of montmorillinite clay and sodium bicarbonate. Use of slightly saline groundwater containing adequate dissolved calcium and magnesium for leaching and reclamation can potentially prevent dispersion of the clay soil particles during treatment. Amelioration was evaluated using shallow, mildly saline groundwater to irrigate sorghum–corn rotations in a two‐year field experiment. After two growing seasons during which a total of 400 mm of leaching water was applied, in addition to some supplemental irrigation water, the average electrical conductivity (ECe) of the top 1.2 m of the soil profile decreased from 14.5±3.5 to 2.7±0.2 dS m−1, and the sodium absorption ratio (SARe) decreased from 35.3±4.1 to 10.1±2.5 (meq L−1)0.5. The soil physical properties were improved: infiltration rate with mildly saline groundwater increased from 12.1 to 42 mm h−1. Salinity changes in the top 1.2 m of soil layers after 700 mm of leaching produced no further improvement. Crop yields produced on plots undergoing amelioration increased by 64–562% compared with the rainfed control. The improved soil conditions after leaching resulted in 59–548% greater crop yields.

Effect of Iron Pyrites, Organic Materials and Micronutrients on Yield of Rice and Wheat and on Amelioration of Sodic Soil

SUMMARYThe effects of iron pyrites, organic materials and micronutrients on the yield of rice and wheat and on the amelioration of saline sodic soil were studied at Kanpur. The grain yield of the first crop of rice increased from 1.37 to 2.97 t ha−1 following application of pyrites at 50% of the estimated gypsum requirement. The grain yield of succeeding wheat and rice crops also increased significantly with pyrites treatment. These increases were associated with marked decreases in pH, electrical conductivity, exchangeable and soluble sodium content and bulk density of the soil and with an increase in its hydraulic conductivity. The beneficial effect of pyrites was increased with the application of rice straw, Sesbania as green manure and micronutrients, the pyrites plus Sesbania green manure treatment being the most effective.

Effect of sedimentary pyrites and Zn application on yield, Zn and Ca nutrition of rice and wheat crops and on amelioration of saline sodic soil

SUMMARYA field experiment was conducted on a saline sodic soil at Kanpur to study the effects of sedimentary pyrites and Zn on the yield, Zn and Ca utilization by rice and wheat crops and on the amelioration of saline sodic soil. The grain yield of the first crop of rice increased from 1·55 t/ha for the ‘control’ to 3·44 and 4·01 t/ha with the 40 and 80% gypsum requirement pyrites treatments. The grain yield of succeeding wheat and rice crops also increased significantly owing to pyrites residues. The favourable effect of pyrites on crop yield was associated with an appreciable decrease in the pH, electrical conductivity and exchangeable and soluble sodium content of the soil resulting in greater utilization of Zn and Ca by the crops. Zinc applications also greatly increased grain yield and Zn uptake by the crops. The higher levels of pyrites with adequate N, P and K fertilizers but without Zn did not give yields that were obtained by adding 11 kg Zn/ha.Significant yield responses were observed in the succeeding wheat and rice crops to Zn residues from the higher Zn treatments. The ‘pyrites+Zn’ treatment was most effective in decreasing the Na content and enhancing Ca uptake which increased the Ca/Na ratio in plants. The Zn treatment alone also decreased soil pH, electrical conductivity and exchangeable Na.