Sustainable management of acid soils through liming and cropping system adjustments

Abstract

Most soil scientists agree that aluminium toxicity is the single greatest chemical barrier to crop production on acid soils. This research evaluated liming rates (0, 2, and 4 t/ha dolomitic lime), Al-tolerant maize cultivars, and legume rotation as management strategies for acid soils (pH 4.2, Al saturation 68%) over four years (2019-2023) at the University of Pretoria’s Hatfield Experimental Farm. Liming at 4 t/ha raised pH to 6.5 and reduced Al saturation to 6.1% by year 4. Combining lime with Al-tolerant cultivars and cowpea rotation recovered 94% of potential yield. Without lime, Al-tolerant cultivars alone recovered 48% and legume rotation 72%. These results support an integrated approach to acid soil management in subtropical Africa.