Sustainable use of phosphogypsum to enhance sandy soils fertility and wheat yield in arid environments

Abstract

Abstract Purpose Sandy soils in arid regions have low fertility, poor structural stability, and limited water‐holding capacity. This study evaluated phosphogypsum (PG) as a soil amendment for improving sandy‐soil quality and wheat productivity under arid conditions. Methods A field experiment was conducted during the 2020/2021 winter season in West El‐Minia, Egypt. PG was applied at 0, 10, 20, and 30 t ha −1 by surface broadcasting or soil incorporation. Soil physical, chemical, and biological properties, wheat yield, and nutrient uptake were evaluated. Results Treatment performance depended on the management objective. Soil incorporation at 30 t ha −1 (T4M4) produced the strongest overall improvement in most soil and microbial indicators, whereas surface application at 20 t ha −1 (T3S3) produced the highest numerical grain yield and nutrient uptake. Under T4M4, bulk density decreased from 1.61 to 1.46 g cm −3 , field capacity increased from 16.0% to 25.16%, available water rose from 11.0% to 19.65%, soil pH declined from 8.2 to 7.8, and cation exchange capacity increased from 4.22 to 9.08 cmolc kg −1 . Microbial biomass carbon and fluorescein diacetate hydrolysis activity increased by 327.7% and 107.6%, respectively. Grain‐yield increases ranged from 29.5% to 60.3% relative to the control. Conclusions Surface application at 20 t ha −1 was the most effective yield‐oriented treatment, whereas incorporation at 30 t ha −1 provided broader soil and microbial improvement. PG recommendations should therefore be selected according to the intended management objective rather than a single generalized optimum.