Biochar-assisted reclamation of saline-sodic soil: Impact on soil properties, barley growth and yield

Abstract

Soil salinity and sodicity are major problems negatively affecting soil properties, fertility, and crop production. In this study, the effect of biochar and phosphogypsum (PG) treatments on the reclamation of saline-sodic silt loam soil was examined. The biochar (BC) treatments included 0.5% (BC0.5), 1% (BC1), and 2% (BC2); two treat - ments of PG (50 and 100%) of the gypsum requirement (GR) in addition to a control (C). Pot experiments were conducted to study the effect of the same treatments on barley growth. The addition of biochar to the saline-sodic soil positively improved soil hydraulic conductivity. BC0.5 had the highest hydraulic conductivity value, followed by BC1 and BC2. All treatments significantly (p<0.05) reduced soil EC, ESP, and SAR below threshold levels. In addition, biochar treatments significantly (p<0.05) reduced the time required for soil reclamation due to improved hydraulic properties and increased salt leaching rates. The best values for growth parameters (plant height, leaf area, plant fresh and dry weight, spike weight, weight of grains per spike, and weight of 1000 grains) were obtained with BC0.5 application followed by PG50 and PG100, respectively. However, a negative effect on plant growth was observed with increased biochar application, as indicated by a noticeable decrease in all growth indicators and chlorophyll content with BC2 and BC1. These findings suggest that biochar produced from calcium-rich raw materials can improve crop growth and soil reclamation.