Changes in soil physical and hydraulic properties from forest and farmland after converting desert to oasis in four typical regions of Xinjiang, China

Aims Converting desert to oases agricultural land generally improved soil structure and local ecology and increased grain yield in arid and semi-arid regions. The present study aims to present how soil physical and hydraulic properties respond to the conversion from desert to oases agricultural land. Methods We compared soils between forest and farmland which were established in the same time in four typical regions (i.e., ILi, Yukang, Hami and Kunyu) of Xinjiang. Soil samples were collected from 0–50 cm soil depth to measure soil water content (SWC), bulk density (BD), total porosity (TP), capillary porosity (CP) and non-capillary porosity (NCP), maximum water capacity (MWC), capillary water capacity (CWC), field capacity (FC) and wilting coefficient (WC), K _s . Results SWC in forest were significantly lower than those in farmland of four typical regions after converting desert to oasis, but BD, TP, K _s , CP, NCP, MWC, CWC, FC and WC in forest were significantly higher than in farmland of ILi, Yukang and Hami, except for lower K _s , MWC, CWC, FC and WC in forest of Hami and Kunyu. The difference in MWC, CWC, FC and WC were greater from forest and farmland with increasing soil depths in four typical regions. In addition, TP, K _s , CP, MWC, CWC, FC and WC were significantly lower but BD and NCP was higher in forest and farmland of other regions, compared with ILi. Conclusions Conversion from desert to oases agricultural land, soil depth and their interaction significantly affected agroecosystem hydrological processes in oasis regions of Xinjiang, China.