Effects of Conservation Tillage on Soil Properties and Maize Yield in Karst Regions, Southwest China

Abstract

Karst rocky desertification associated with human disturbance is one of the most serious eco-environmental problems, threatening the sustainable development of agriculture in southwestern China. In the current study, the practice of conservation tillage as one of the best ways of reducing the constraints is addressed. During a two-year trial (2014–2015), the effects of no tillage with straw cover (NT) and traditional tillage (TT) on soil properties and maize yields were investigated in karst regions, Southwest China. The results showed that the trial with NT increased soil moisture content by 3%, while decreasing soil bulk density by 7% in the top 30 cm compared with TT. In 2014, within 0–30 cm of soil depth, total nitrogen under NT treatment was 5% higher than that under TT treatment. In 2015, the mean soil organic matter (SOM) and available P were enhanced to 12% and 13% in 0–30 cm soil depth more than that under TT, respectively. The trial with NT significantly (p < 0.05) increased available N in the top 20 cm by 9% as compared to TT. This improvement in soil physical and chemical properties might have increased the crop yield. After the two-year trial with NT, the mean maize yields increased by 11% compared with the TT trial. Therefore, conservation tillage is the better option considering long-term environmental sustainability in karst regions.