Leaching and reclamation of calcareous saline‐sodic soil by moderately saline and moderate‐SAR water using gypsum and calcium chloride

Abstract

Lysimeter experiments were conducted with sandy-clay-loam soil to study the efficiency of two amendments in reclaiming saline-sodic soil using moderately saline and SAR (sodium-adsorption ratio) irrigation water. Gypsum obtained from industrial phosphate by-products and reagent grade Ca chloride were applied to packed soil columns and irrigated with moderately saline (ECe = 2.16 dS m -1 ), moderate-SAR water (SAR = 4.8). Gypsum was mixed with soil prior to irrigation at application rates of 5, 10, 15, 20, 25, and 32 Mg ha -1 , and Ca chloride was dissolved directly in leaching water at application rates of 4. 25, 8.5, 12.75, 17.0, and 21.25 Mg ha -1 , respectively. The highest application rate in both amendments resulted in 96% reduction of total Na in soil. The hydraulic conductivity (HC) of soils receiving gypsum increased in all treatments. The highest HC value of 6.8 mm h -1 was obtained in the highest application rate (32 Mg ha -1 ), whereas the lowest value of 5.2 mm h -1 was observed with the control treatment. Both amendments were efficient in reducing soil salinity and sodicity (exchangeable-sodium percentage, ESP); however, Ca chloride was more effective than gypsum as a reclaiming material. Exchangeable Na and soluble salts were reduced with gypsum application by 82% and 96%, and by 86% and 93% with Ca chloride application, respectively. Exchangeable Ca increased with increasing amendment rate. Results of this study revealed that sodium was removed during cation-exchange reactions mostly when the SAR of effluent water was at maximum with subsequent passage of 3 to 4 pore volumes. Gypsum efficiently reduced soil ESP, soil EC, leaching water, and costs, therefore, an application rate of 20 Mg ha -1 of gypsum with 3 to 4 pore volumes of leaching water is recommended for reclaiming the studied soil.

Sustainable Management of Calcareous Saline-Sodic Soil in Arid Environments: The Leaching Process in the Jordan Valley

“…Therefore, utilizing agricultural drainage water for leaching processes until reaching 20 dS m −1 of drained water can save around 66% (13200 m 3 per hectare) of fresh water requirements [27]. One drawback of this approach is that using brackish water consumes a larger amount of water compared to the amount needed for leaching with fresh water [28,29]. Additionally, soil swelling might take place too which may lead to an increase in volume as the soil gets wet and shrinks as it dries out.…”

First and second-year assessments of the rapid reconstruction and re-vegetation method for reclaiming two saline–sodic, coastal soils with drip-irrigation

“…5), and nearly 30 species of landscape plants, including some salinity-sensitive species, were proposed with survival up to 90% after one or two years. Meanwhile, the approach is applicable to the field condition, which is very different from the traditional reclamation methods mainly used in soil columns, lysimeter experiments, laboratory experiments or greenhouse conditions (Ammari et al, 2013;Gharaibeh et al, 2011Gharaibeh et al, , 2009Hanay et al, 2004;Mahmoodabadi et al, 2013;Miranda et al, 2011;Nayak et al, 2008;Oster et al, 1999;Qadir et al, 1996;Sidhu et al, 2004;Siyal et al, 2010;Somani, 1981).…”

“…These procedures fail to reclaim highly dispersed, hard, sodic and saline-sodic soils due to their low profile permeability (Nayak et al, 2008;Sumner, 1993). Although saline water can be used as an alternative to freshwater and leaching salt with saline water can save time and water in the reclamation of saline-sodic soils, irrigation with low electrolyte concentration has been most favored (Gharaibeh et al, 2009;Vander Pluym et al, 1973;Steppuhn, 2001). With either choice, salt build-up would probably occur during periods of low precipitation, warm temperatures, and insufficient leaching (Khoshgoftarmanesh et al, 2003).…”

Enxofre elementar ou sulfato de cálcio para remediação de solos salino-sódicos?

“…Assim, produtos como resíduos orgânicos, sulfato ferroso, cloreto de cálcio, sulfato de cálcio, ácido sulfúrico e enxofre elementar têm sido os mais estudados com essa finalidade (Pitman & Laüchili 2002, Zia et al 2007, Mohamed et al 2007, Sousa et al 2012, Sá et al 2013a. Dentre esses produtos, o enxofre elementar e o sulfato de cálcio parecem ser os mais promissores, quando o excesso de sais é acompanhado pelo excesso de Na trocável (Gharaibeh et al 2009, Gill et al 2009, Golldack et al 2011. Contudo, devido ao seu baixo custo e facilidade de aquisição, o sulfato de cálcio tem sido o produto mais empregado (Leite et al 2007, Gill et al 2008, Leal et al 2008, Melo et al 2008, Pazhanivelan et al 2008.…”