Effect of soil surface mulching and N rate on dry matter and nitrogen accumulation and translocation of winter wheat

Field experiment was carried out at the south part of the Loess Plateau,to study the effects of different soil surface mulching methods and N rate on winter wheat growth and nitrogen accumulation and translocation in plant in dif- ferent years.The results showed that mulching soil surface with plastic film increased dry matter accumulation in the growth period from reviving stage to harvesting stage,improved dry matter translocation or dry matter accumulation after anthesis.Mulching with wheat straw promoted dry matter accumulation in reproductive stage,and with the extension of cropping years,wheat straw mulching increased biomass and grain yield and showed no significant difference compared with the plastic film mulching.The results also showed that plastic film mulching increased N accumulation from reviving stage to harvesting stage and N translocation during reproductive stage.Wheat straw mulching promoted N accumulation after anthesis,and showed no significant difference in increasing N uptake in plant and grain compared with the plastic film mulching with the extension of cropping years.Nitrogen fertilization significantly increased dry matter and N accumu- lation in winter wheat at each growth period,promoted post-anthesis dry matter accumulation and redistribution of N accu- mulated before flowering,and significantly increased biomass and grain yield,as well as their N uptake.