The effects of conservation tillage practices on the soil water-holding capacity of a non-irrigated apple orchard in the Loess Plateau, China

Six tillage practices were studied in an apple orchard located in the Loess Plateau from 2007 to 2009. The objective was to investigate the effects of tillage practices on the soil water-holding capacity in a nonirrigated orchard in China. The results showed that different tillage practices had varied effects on the water-holding properties. Subsoil tillage with straw mulching, plow tillage with straw mulching and no tillage with straw mulching showed a decrease in the soil bulk density and an increase in the soil porosity, soil saturated water content and soil moisture relative to plow tillage in bare soil (i.e., conventional tillage). Among these three tillage practices, the subsoil tillage with straw mulching and no tillage with straw mulching treatments had a significant effect on the soil porosity, soil saturated water content and soil moisture compared to the plow tillage with straw mulching treatment. These results indicate that the subsoil tillage with straw mulching, plow tillage with mulching and no tillage with mulching treatments improved the soil structure and water-holding capacity of the apple orchard. However, the no tillage with bare soil and no tillage with grass treatments increased the soil bulk density and decreased the soil porosity and soil moisture content compared to conventional tillage. This finding demonstrates that no tillage with bare soil and no tillage with grass had adverse effects on the soil structure and water-holding capacity. From the results of this study, we concluded that the subsoil tillage with straw mulching treatment is the optimum practice of the six studied treatments for improving the soil water-holding capacity in this non-irrigated apple orchard in the Loess Plateau of China.