LYU Jian, LI Jinwu, YU Jihua, XIE Jianming, FENG Zhi, ZHANG Guobin, LIU Na, WANG Junwen
In order to explore the cultivation effect of plateau summer vegetables in semi-arid areas under different surface cover methods, taking loose-curd cauliflower as experimental material. There were five treatments: open field without covering (CK1), plastic film covering (CK2), plastic film + straw covering (T1), straw inter row covering (T2) and whole straw mulching (T3). The effects of different mulching methods on soil temperature, yield and water use efficiency of loose-curd cauliflower were studied. The results showed that: compared with open field without covering, plastic film + straw covering treatment significantly increased the plant height, stem thickness and leaf area of loose-curd cauliflower, however there was no significant difference among plastic film covering; straw inter row covering and whole straw mulching treatments inhibited the vegetative growth of loose-curd cauliflower plants. Compared with open field without covering, the plastic film + straw covering treatment had obvious warming effect, and the maximum increase in temperature of T1 treatment occurred in the 10 cm soil layer of the spring stubble test rosette stage and the 5 cm soil layer of the autumn stubble test seedling stage. Both straw inter row covering and whole straw mulching treatments had dual effects on increasing and decreasing temperature to varying degrees. Compared with plastic film covering, plastic film + straw covering treatment could achieve the effect of plastic film mulching on soil temperature. Meanwhile, in autumn stubble experiment, plastic film + straw covering treatment had a significant effect on increasing temperature, the soil temperature of 5 cm and 10 cm increased by 2.5℃ and 1.8℃ in the seedling stage, which as more conductive to the growth and development of loose-curd cauliflower seedings. And straw inter row covering and whole straw mulching treatments showed cooling effect at each growth stage and soil layer, and whole straw mulching treatment had the most obvious cooling effect. Compared with the open field without mulching and plastic film mulching, in the spring stubble experiment, the biological output of plastic film + straw inter row mulching treatment increased by 32.3% and 2.7%, economic output increased by 68.9% and 4.7%, water saving increased by 29.0% and 7.3%, and water use efficiency increased by 137.8% and 13.1%, respectively; In the autumn stubble experiment, biological yield increased by 4.7% and 2.4%, economic yield increased by 27.8% and 8.4%, water saving increased by 23.8% and 11.1%, and water use efficiency increased by 67.2% and 21.9%, respectively. Comprehensive analysis showed that plastic film + straw covering treatment had a good effect on temperature regulation, moisture retention, significant increase in production and efficiency, which was more advantageous than mulch planting in Yuzhong area.