Effects of sowing density and N rate on biomass accumulation and yield of winter wheat in furrow and ridge film mulching

The aim of this study was to harmonize the relationship between individual and population,and establish a suitable community structure,and fully apply the advantages of furrow and ridge cultivation in rainfed land areas.The successive two year field experiments were conducted to investigate the effects of sowing density and N rate on yield,and dry matter accumulation of individual and population of winter wheat in the furrow and ridge film mulching planting system.The central composite rotatable design with two factors of seeding density and N rate was used in the experiments.There were five levels of sowing density,75,85.95,112.5,139.04 and 150 kg/ha,and five N levels of N rates,120,137.57,180,222.43 and 240 kg/ha.The tested cultivar was Xiaoyan 22.The results show that the dry matter accumulation of individual winter wheat is significantly affected by sowing density,and the accumulation is decreased when the sowing density is increased.There are significant different dynamics of the dry matter accumulation of population in the two year experiments owing to difference weather.The dry matter accumulation of population is decreased as the sowing density is increases in 2009,while that is increased in 2010.Although there are no effects of nitrogen application on individual biomass at the anthesis stage,there are significant effects of N on biomass at the maturity stage.The nitrogen fertilization could increase the dry matter accumulation of population remarkably at the two stages.These results indicate that there are some effects of the sowing density and nitrogen rate on the dynamics of plant individual and population,the winter wheat has capacity to regulate their population according to environmental condition.Therefore,it could not to increase the population with higher sowing density blindly.The efficient nitrogen application is benefit to the individual and population growth.Under this experiment condition,the medium sowing density(112 kg/ha) and the higher nitrogen rate(201-214 kg/ha) are benefit to optimize relationships of individual and group,and achieve a high biomass and yield.