Effects of Leaching on the Reclamation of Saline Soils as Affected by Different Organic and Inorganic Amendments

Abstract

Soil salinity, which poses one of the greatest threats to sustainable crop production worldwide, can be ameliorated through various approaches, such as leaching, mulching, and amendment application. The effects of leaching and amendments on saline soil reclamation have been studied separately, but their interaction is poorly elucidated. Therefore, a column experiment was designed with soils that were subjected to leaching with 2 and 4 pore volume (PV) of water and compared with non-leached soils (NLS) to observe the effects of leaching on saline soil and leachate characteristics under different organic (vermicompost [VC] and wood ash [WA]) and inorganic (zeolite) amendments at two different rates (1 and 2 g 100 g −1 ) and their combinations. Results revealed that the electrical conductivity (EC) of the soil decreased, whereas the EC of the leachate increased as the PV of water increased. Regardless of the treatments, the concentrations of sodium (Na + ), potassium (K + ), calcium (Ca 2+ ), and magnesium (Mg 2+ ) in the leachate increased. By contrast, their concentrations in the leached soils decreased as the PV of water increased. WA contributed to a significant increase (p < 0.01) in the EC and the concentrations of cations, especially K + and Ca 2+ , in the soils and leachates. The higher the rates of the amendment, the greater the increment in the EC and cation concentrations. Incorporating amendments could be important sources of cations, thereby limiting the entry of Na + into the exchange complex and facilitating leaching with percolating water. The response of spinach (Spinacia oleracea) in terms of yield parameters to 2 PV of leached soils was significantly better than that of NLS, suggesting that soil leaching could significantly influence plant functioning in highly saline soils. This study suggested that the irrigation of saline soils under different organic and inorganic amendments before cultivation might affect salt leaching and soil nutrient dynamics, thereby influencing plant growth and yield.

Study of spatio-temporal variations of soil salinity in the south-eastern coastal part of Bangladesh

“…SRDI (2010) also stated that Na + , Ca 2+ , Mg 2+ and K + are the dominant cations found in saline soils, and the ionic preponderance decreased in the order of Na + > Mg 2+ > Ca 2+ > K + in areas under the influence of brackish water. The positive correlation of EC with that of other cations and anions (Table 1 and 2) in the present study was in consistent with other findings (Cebas-Csic et al, 1997;Roy et al, 2020;Roy and Chowdhury, 2020b). The EC of soil solution is the measure of its ability to conduct an electric current which usually depends on the number of ions present in the soil, and the higher the concentration of dissolved ions in soil solution, the higher its EC (Brady and Weil, 2005).…”

“…Compared to the pre-monsoon season, the soil pH of all the sampling sites in the post-monsoon season increased which was likely due to the removal of SO 4 2with rain water during the monsoon period. In the recent study, Roy and Chowdhury (2020b) observed that the leaching of acidic saline soils resulted in an increased pH compared to non-leached soils.…”

“…This could be due to the leaching of soluble salts during monsoon rain. Saline soils contain salts of Na + , K + , Ca 2+ and Mg 2+ in association with Cl -, SO 4 2and HCO 3 which are soluble and leachable with irrigation water (Zhang et al, 2014;Roy and Chowdhury, 2020b).…”

Quantitative Estimation of Saline-Soil Amelioration Using Remote-Sensing Indices in Arid Land for Better Management

“…In the study case, saline soils should be treated, and subsequently sodic soils, in order to reduce the concentration of salts to the appropriate degree for the growth of plant roots and even the appropriate depth for the roots [114][115][116][117][118][119][120].…”

“…Cotton and sugar beet are the most important salt-tolerant crops, while sugar cane, fava beans, and peas are the least tolerant of salinity. Most vegetable crops are moderately resistant to salinity, while most fruit crops, especially deciduous, are sensitive to salinity [114][115][116][117][118][119][120][121][122][123][124].…”