Effects of different management intensities on soil quality of farmland during oasis development in southern Tarim Basin, Xinjiang, China

Abstract

Soil quality is a key environmental factor in developing sustainable agricultural. In the oases located at the southern margin of the Tarim Basin of Xinjiang, China, agriculture is the main land use type. However, management intensities differ in the oases and in the process of oasis growth. In 2004, four experimental fields were established in the Cele oasis, representing four typical land-use types according to local farmers tillage practices, namely newly cultivated land (NEF), a field with normal fertilization (NMF), a field with high fertilization (HMF), and a field in the oasis' interior (OIF), in order to analyze the effects of land-use type on soil nutrient content. Additionally, soil from an uncultivated control plot (CTP) was analyzed for comparison. The soil quality index (SQI) and deterioration index (DI) were used to evaluate the effects of different land-use type. Sustainable yield index (SYI) was calculated to evaluate sustainable productivity of these land-use types, based on 4 years of data. Our results indicate (i) statistically significant differences in SOM, total nitrogen N (TN), total phosphorus (TP), and available phosphorus (AP) between the different farmlands; (ii) NEF, in the desert–oasis ecotone, had the lowest soil quality, even lower than CTP, and lowest indicator values; (iii) fertilization of NMF and HMF in the desert–oasis ecotone had a positive effect on soil nutrient content; however, sustainable productivity of these farmlands is low, and much ground water is consumed; and (iv) farmland (OIF) in the oasis interior had the highest values in all assessments. Our study indicates that farmland in the desert–oasis ecotone should be reclaimed prudently, using sustainable development insights.