Biochar, manure, and super absorbent increased wheat yields and salt redistribution in a saline-sodic soil

Salinity and sodicity problems are ubiquitous in dryland and irrigated systems, and research into possible amendments to remediate soils in these systems is needed. This study was conducted to investigate the effects of organic and inorganic amendments on spring wheat (Triticum aestivum UG99) yield and salts redistribution within the profile of a repacked saline-sodic silt loam soil (ECe = 12.9 dS m(-1), exchangeable sodium percent (ESP) = 17.6% for control). The experimental design for greenhouse study was completely random with two factors (amendment and leaching fraction, LF). The amendments included biochar (2%) [B], biochar + manure (2%) [BM], zeolite modified with CaCl2 (2%) [ZC], super absorbent (1%) [SA], and a control (no amendment) considering two levels of LF (15 and 30%). All amendments, except ZC, decreased soil bulk density and electrical conductivity, and increased soil pH and water content at field capacity after 2 pore volumes leaching. There was positive effect (p < .001) of B, BM and SA on wheat ground cover and grain yield; ZC amendment had no effect on wheat growth or yield. The LF levels did not affect wheat growth or yield. The amendments (B, BM and SA) decreased Na+ and Mg2+ concentration in straw, while K+ concentration increased; resulting in reductions in the Na+/K+ ratio. In general, the study showed that B, BM and SA are suitable amendments for increasing yield by improving soil conditions and reducing salts and Na+ accumulation in plants.