Effects of various cultivation systems on soil water space-time dynamics and yield of rainfed spring maize

To assess the impacts of different cultivation systems on the characteristics of space-time dynamics on soil moisture and water use efficiency(WUE),which could be helpful for increasing grain yield and WUE in dryland maize production in semi-arid regions,a field trial was conducted at the Changwu experimental station in2012 and 2013. Four treatments were carried out including farmers' practice(N 200 kg ·hm-2,ridges covered with plastic film,CK),T1 treatment(N 380 kg·hm-2,ridges and furrows both covered with plastic film),T2treatment(N 225 kg·hm-2+ Organic fertilizer,ridges and furrows both covered with plastic film),T3 treatment(N 225 kg·hm-2+ Organic fertilizer,ridges and furrows both covered with plastic film and removing plastic film at silking stage). Compared to farmers' practice,T1,T2 and T3 treatments could not only efficiently use water in the 0 ~ 100 cm soil layers,but also use water in the 100 ~ 200 cm soil layers. At harvest,no significant differences in soil water content were observed between treatments. Water consumption levels during the whole growing stage of the four treatments were in the order of T3 T2 T1 CK,and the grain yields followed the same. Because the rate of yield increase was higher than that of water consumption,the water use efficiencies of the four treatments were also found to be in the same order as T3 T2 T1 CK. In conclusion,the cultivation systems that ridgesand furrows both were covered with plastic film improved not only grain yield but also water use efficiency,especially in the plots where plastic film was removed at the silking stage. This cultivation system could be helpful for increasing grain yield and WUE of dryland maize in semi-arid regions.