No-tillage with straw mulching could increase grain yield, water and nitrogen use efficiencies of summer maize

ObjectivesConservation tillage has been received wide attention in agriculture of arid and semiarid regions due to its advantages in conserving soil and water and increasing yield. But its effects vary owing to landscapes, climate condition and cultivation system. The aim of the study was to investigate the adaption of three conservation practices in the semi-humid and sensitive to drought area and to provide theoretical basis and technical foundation for selection and optimum of conservation tillage practices in similar areas.

MethodsThe experiment was conducted in Guanzhong Plain, Shaanxi, China from June 2014 to October 2015. The field experiment was in a split-plot design, and three tillage methods, rotary and ridge tillage (RT), no-tillage (NT) and no-tillage with straw mulching (NTM) were assigned to the main plot and nitrogen levels (N230 and N0) were the subplot.

Results1) Compared to the NT and RT treatment, the average moisture contents in the cultivation layer (0–20 cm) of the NTM treatments in summer maize growing season were increased, the temperature was decreased and yields were increased significantly, and the average yields of the NTM treatments in the two years were increased (P<0.05) by 13.2% and 41.8% respectively. 2) The NT and NTM treatments could cut down water consumption, increase the amount of nitrogen uptake and improve the water and nitrogen use efficiencies of summer maize significantly. Compared to the RT treatment, the water use efficiencies of the NT and NTM treatments in the 2 years were increased by 7.1 and 10.3 kg/(hm²·mm) (P<0.05), respectively, and the nitrogen use efficiencies were increased by 3.8 and 10.1 percentage points (P<0.05), respectively. 3) Compared with the N0 treatment, the N230 treatment could promote growth of summer maize, and increase the amount of nitrogen uptake, grain yield and water use efficiency. The average of grain yield and water use efficiency for the N230 in the two years were increased by 49.5% and 50.5% (P<0.05), respectively.

ConclusionsThe no-tillage with straw mulching could increase grain yield, water and nitrogen use efficiencies and adapt to summer maize practice in the semi-humid and sensitive to drought areas.