Effects of Different Cover Types on Soil Water,Temperature and Potato Yield in Double Rice Cropping Area

Soil water and soil temperature are two important environmental factors, which affect winter potato production in double rice cropping area. This research was carried out to compare with the effects of different mulching types on soil water, soil temperature and winter potato production in Changsha County of Hunan Province. In this study, four mulching type, i.e. rice straw (RS), water- permeability plastic film (WPPF), common plastic film (CPF), black plastic film (BPF), and no-covering as control (CK). Results showed as follows: mulching rise the soil temperature at 0 cm -20 cm layer, and effects of different mulching types showed CPF>WPPF>BPF>RS>CK. At 0 cm -5 cm layer, RS significantly improved soil moisture by 5.9% than CK at 5% level; mulching film (i.e. WPPF, CPF and BPF) significantly decreased soil moisture at 0 cm -15 cm layer, but had no significant effect on it at 20 cm -25 cm layer. WPPF significantly reduced the soil bulk density at 0 cm -5 cm layer by 2.0%, and RS significantly decreased it than CK by 4% at 15 cm -20 cm layer at 5% significance level. Mulching was the disadvantage of seedling emergence of potato, except WPPF. RS significantly decreased the rate of potato seedling emergence by 21.7% at 5% significance level. WPPF and BPF significantly increased tuber yield than CK by 22.0% and 6.9% ; however, RS and CPF significantly decreased it by 21.2% and 19.5% at 5% probability level. WPPF obtained the maximum big potatoes, the highest rate of economic potato and the highest starch content of tuber potato among other's treatments. Our results suggest that WPPF had some advantages in maintaining soil water content and soil temperature and enhanced the yield and quality of winter potato tubers in double rice cropping area