In order to explore the ways of water-holding

yield-increasing and high-efficiency cultivation technology of dryland wheat

a field experiment was carried out at the Wenxi Experimental Base of Shanxi Agricultural University during 2011 to 2014. Taking the summer mulching with water-permeable plastic film and non-mulching as the main plots

and sowing patterns

i.e. inter-mulching drilling（FM） and conventional drilling (CD）as sub-plots

the effects of interannual mulching in different precipitation years on soil water movement

plant nitrogen accumulation and utilization

and nitrogen efficiency in dryland wheat field were studied. The results showed that the soil water content in the first 3 m soil layer before sowing could be improved by summer mulching

and the effect of water conservation could last to the booting stage

with FM having better effects. Summer mulching increased N accumulation of plants at different growth stages

the effect was significant in humid years

in which N accumulation was increased by 27 kg/hm2 to 31 kg/hm2

and the FM under summer mulching could increase N accumulation significantly

i.e. by 2 kg/hm2 to 8 kg/hm2 in dry years. Summer mulching could promote N mobilization in leaves and spikes in humid years

promote N mobilization in stems + sheaths in normal years and dry years

and increase N mobilization and their contributions to grain before anthesis

especially dry years. Summer mulching could also promote N mobilization in stems + sheaths in normal years and in leaves in dry years

increase N mobilization and their contributions to grain after anthesis by using FM. Nitrogen use efficiency and nitrogen production efficiency were improved by summer mulching

and nitrogen absorption efficiency was better under FM in dry years; nitrogen absorption efficiency was increased by FM

and summer mulching had greater impact on nitrogen production efficiency in dry years. The results also showed that after summer mulching

the yield of N accumulation per unit after anthesis was significantly higher in humid and normal year

an 1 kg/hm2 increase of N accumulation could increase yield by 176 kg/hm2 to 224 kg/hm2. The yield of N accumulation per unit before anthesis was larger in dry years

with the yield being increased by 142 kg/hm2 to 185 kg/hm2. Compared with the CD

the yield of N mobilization per unit before anthesis and N accumulation per unit after anthesis were higher than those under FM in humid and normal years

the yield of N mobilization per unit after anthesis was higher under summer mulching condition with FM in dry years

an 1 kg/hm2 increase of N accumulation could increase the yield by 234 kg/hm2. In conslusion

interannual mulching is beneficial to nitrogen absorption and mobilization by plants

and high yield and high efficiency of dryland wheat.