Abstract
Conservation tillage (CT) is widely promoted as a sustainable alternative to conventional tillage (CVT) in semi-arid regions, where soil erosion and low water availability threaten crop productivity. This study synthesizes field experiments from 15 semi-arid sites across Africa, Asia, Europe, and the Americas to quantify the effects of CT on soil erosion rates and crop yields. Results from a meta-analysis of 120 paired observations show that CT significantly reduces soil erosion by an average of 42% compared to CVT, with no-till (NT) and reduced tillage (RT) being equally effective. Crop yield responses are variable: NT yields are similar to CVT in 60% of cases, but 20% show yield reductions under NT, particularly in cooler regions. RT often maintains or increases yields by 5–10% due to improved soil moisture. Soil organic carbon (SOC) increased by 0.15 Mg ha⁻¹ yr⁻¹ under CT, positively correlating with yield stability. We conclude that CT, especially RT, offers a viable pathway for sustainable intensification in semi-arid areas, but site-specific adaptation is necessary to avoid yield penalties. Policy implications include promoting RT in regions with high erosion risk and providing support for residue retention.
Keywords
conservation tillage, soil erosion, crop yield, semi-arid regions, no-till, reduced tillage, soil organic carbon, sustainable agriculture