Boron (B) toxicity limits crop production in arid and semi-arid soils. This study evaluated a sheep wool-poultry litter ash biocomposite (WASH) for mitigating B toxicity in maize and a subsequent sorghum crop. A pot experiment was conducted using four soils collected from different sites with contrasting plant-available B concentrations (1.2, 3.1, 6.1, and 9.3 mg kg− 1), to which WASH was applied at rates of 0, 1, 2, and 4 g kg− 1. Dry matter production, plant B, N, and P concentrations, and post-harvest soil plant-available B and P were determined. WASH application significantly increased biomass across all soils, with the greatest relative improvements observed in soils with moderate (6.1 mg kg− 1 B) to high B levels (9.3 mg kg− 1 B). Optimal maize growth was generally achieved at the 2 and 4 g kg− 1 rate of WASH application rate, while biomass in the highest-B soil increased progressively with increasing WASH application. Plant B concentrations in both crops increased with soil B content but were substantially reduced by WASH application in soils containing 6.1 and 9.3 mg kg− 1 B, indicating effective regulation of B uptake. Sorghum grown subsequently exhibited clear residual benefits of WASH, with dry weight responses varying according to soil-B level and application rate. Post-harvest soil analyses showed no consistent trend for plant-available B, while plant-available P increased significantly with increasing WASH rates after both cropping cycles. The WASH biocomposite effectively mitigated B toxicity by regulating plant B uptake and enhancing nutrient availability and crop productivity, demonstrating its potential as a sustainable, waste-derived amendment for B-affected soils.
Güneri̇ et al. (Sat,) studied this question.