Abstract:

In order to meet of water requirement of maize growth at the situation of limited and unevenly distributed rainfall and the problem of serious spring drought in Gansu dry farming area. The effects of four different film-covering times on growth stages, soil moisture variation, water use efficiency, yield and economic benefit of dry land maize were studied in the field. The results showed that the full mulching on double ridges in autumn was better than full mulching on double ridges in early spring and full mulching on double ridges in middle spring and full mulching on double ridges before sowing, the early film-covering was batter than latter film-covering. The full mulching on double ridges in autumn increased rainfall use rate and water use efficiency. Rainfall use rate of the full mulching on double ridges in autumn was 70.21%, water use efficiency was 30.19 kg/(hm2?mm). The yield of corn production with the full mulching on double ridges in autumn was 10039.34 kg/hm2, which was higher 24.81% than the full mulching on double ridges before sowing as well as water use efficiency raised 15.26%, respectively. The results displayed that the way of full mulching on double ridges in autumn could reduce the useless evaporation of soil water in winter and spring，increase soil moisture content, improve the economic characters of maize and increase the yield of maize and net income. It was an effective way to further exploit rainfall productive potential and create high-yielding fields in dry farming areas.