Farmland management effects on the quality of surface soil during oasification in the southern rim of the Tarim Basin in Xinjiang, China

Oasification and desertification are basic geographical processes in arid areas, and both change the soil properties and quality. Recently, oasification has been obvious in the southern rim of the Tarim Basin of Xinjiang, China, and agriculture is the main land-use type. There has been little research on oasification involving farmland of different management types in extremely arid regions. In 2004, four experimental fields were established in the Cele Oasis, representing four typical land-use types of local farmers' tillage practices during oasification. Three experimental fields were situated in the desert-oasis ecotone: newly cultivated land (NEF), a field with normal manure input (NMF), and a field with high manure input (HMF); there was also another field in the oasis interior (OIF), to allow analysis of the management effects on soil properties and soil quality of farmlands. Additionally, the soil from an uncultivated control plot was analyzed for comparison. Both a Soil Quality Index based on soil properties and a Sustainable Yield Index based on yearly yield were used to assess the soil quality of the different farmlands. There were significant differences in seven soil indicators, including soil particle size distribution and soil organic matter, between the four locations. NEF had the lowest and OIF the highest values in all assessments among the five experiment plots. Fertilization of NMF and HMF had positive effects on soil properties and soil quality; however, the sustainable productivity of these farmlands was low. The results should be beneficial for refining agricultural management practices and improving sustainable land use in the oasification process.