Impact of conservation practices on soil hydrothermal properties and crop water use efficiency in a dry agricultural region of the tibetan plateau

Abstract

Mulching combined with a ridge-furrow system (MRFS) has been regarded as a suitable management method for alleviating the hydrothermal limitation of crop production in semiarid regions. However, whether this practice can be extended to high altitude alpine agricultural regions remains unclear. In order to evaluate the effectiveness of MRFS in improving soil hydrothermal properties, crop yield and water use efficiency (WUE) in alpine regions, a field experiment was conducted on the Tibetan Plateau (TP) with three treatments including: mulching with ridge-furrowing (MR), mulching with flat planting (MF), and bare soil with flat planting as a control (CK). The results indicated that MR performed best in terms of increasing soil water content within a depth of 10–50 cm after irrigation and precipitation at the sprout stage, and in maintaining significantly higher (P < 0.05) soil water storage (SWS) in the 50–110 cm soil layer throughout the whole growth period. Thermal performance in the 20 cm soil depth was also best in MR, with an average temperature increase of 1.1 °C compared to CK. Evaporation was significantly lower (P < 0.05) in MR compared with CK, although the highest evapotranspiration rate was observed in MR. Higher values for plant height, ground diameter, leaf area index (LAI) and fine root length density (FRLD) were found in MR. In comparison with CK, yield was 16 % higher, WUE was improved by 3 % and benefit was improved by 11.7 %. These results suggested that MR represents an efficient planting pattern for improving soil hydrothermal properties and crop yield on the TP.