Climate drives global soil carbon sequestration and crop yield changes under conservation agriculture

TLDR

Conservation agriculture, particularly no‑till, offers soil, yield, and environmental benefits, yet carbon sequestration and yield gains are not always achieved, and regional climate must be considered. The study aims to globally assess the impact of no‑till on soil carbon and crop yield. This assessment uses 260 paired studies for soil carbon and 1,970 for crop yield. The results indicate that arid regions gain both soil carbon and yield, humid regions mainly increase soil carbon, and colder regions may suffer yield losses and soil carbon loss.

Abstract

Conservation agriculture has been shown to have multiple benefits for soils, crop yield and the environment, and consequently, no-till, the central practice of conservation agriculture, has rapidly expanded. However, studies show that the potential for carbon (C) sequestration in no-till farming sometimes is not realized, let alone the ability to maintain or improve crop yield. Here we present a global analysis of no-till-induced changes of soil C and crop yield based on 260 and 1,970 paired studies; respectively. We show that, relative to local conventional tillage, arid regions can benefit the most from conservation agriculture by achieving a win-win outcome of enhanced C sequestration and increased crop yield. However, more humid regions are more likely to increase SOC only, while some colder regions have yield losses and soil C loss as likely as soil C gains. In addition to site-specific characteristics and management, a careful assessment of the regional climate is needed to determine the potential benefits of adopting conservation agriculture.