LONG–TERM STRAW RETENTION DRIVES CARBON SEQUESTRATION AND CROP PRODUCTIVITY IN DRYLAND SOILS

Abstract

Higher population densities in rural areas and climate change have necessitated technical change in crop production. Intensification without causing degradation is required to cope with changing population dynamics. A study was conducted to assess the influence of tillage systems on crop yield and soil carbon balance in a long-term spring wheat−field pea rotation in a rain–fed semiarid Loess Plateau environment. Experimental work included the following treatments: conventional tillage with straw removed (T), no till with straw removed (NT), no till with straw retention (NTS) and conventional tillage with straw incorporated (TS). Straw treated soils resulted in decreased soil temperature and increased soil moisture compared to soils with straw removed. No tillage with straw retained treatments produced the highest average grain yield of 1809 kg ha–1 on average than that of conventional tillage with straw removed (1280 kg ha–1) and no till with straw removed (1337 kg ha–1). No tillage with straw retained and conventional tillage with straw incorporated had positive soil C balance, but the effect was greater on no tillage plots. The lower C inputs under treatments with straw removed translated into negative soil C balance. NTS farming practices demonstrated sustained increases in soil quality and crop productivity, whiles treatments with straw removed reduced carbon inputs in dryland cropping system.