Effect Of Film Mulching Cultivation On Rice Yield And Nitrogen Use Efficiency Of Rice At Hilly Region In Sichuan Province

This study researched the effects of film mulching cultivation in different types of paddy soil (gleyed paddy soil, percogenic paddy soil and submergenic paddy soil) on rice growth, nitrogen uptake and use efficiency in Ziyang city Yanjiang district Xiangshui village in2011.At the same time on the effects of unraveling film in medium stage and nitrogen dressing fertilizer under film mulching cultivation on rice growth, nitrogen uptake and utilization efficiency.Aim to elucidate the effect of film mulching cultivation on paddy growth on main paddy soil in hilly area of central Sichuan Basin to solve the problems of fertilizer removal in the later stage and low recovery rate of film,and ect Finally provide theoretical basis for rice film covering technology promotion in hilly area of central Sichuan Basin.The main results of this study are as follows:(1) Mulching cultivation promoted the growth of rice, increased the rice tillering number, the largest seedling number was significantly higher than that of traditional culture, thereby increased the effective panicle number, increased crop yields, in the same condition of nitrogen fertilizing increased the yield by20%.In film mulching cultivation. reducing nitrogen fertilizing rate by1/3.namely120kg/ha,stalk and tillering numbers of rice in the early stage will decreased,but prevented the formation of ineffective tillering.increased rice spike rate and effective tillering number,and kept rice yield in high level; In three sorts of paddy soil, appropriate reducing nitrogen fertilizing rate in film mulching cultivation,namely120kg/ha and180kg/ha, there were insignificant differences in the yield of rice,besides reducing nitrogen fertilizing rate would improve the yield of rice in both gley soil and submergic soil.(2)Soil mulching increased nitrogen uptake of rice in different paddy soil, improved the absorption efficiency.increased the nitrogen uptake efficiency. The phenomena in gley soil and submergic soil were especially obvious, Reducing nitrogen rate by1/3in film mulching cultivation, namely120kg/ha, owned nitrogen uptake of up-ground part of plants which were insignificant different to it of180kg/ha treatments; Reducing nitrogen fertilizer could effectively improve the plant nitrogen uptake and utilization efficiency of nitrogen in rice to more than40%.(3)Film unraveling nitrogen fertilizing under film mulching cultivation effectively solved the problem of insufficient supply in the later stage, promoted rice growth effectively reduced the ineffective tillering, increased rice spike rate, the maximum increase rate were20%, thereby improved yield, especially the treatments of120kg/ha base fertilizer and60kg/ha ear fertilizer in one time could increased yield significantly for600kg/ha.otherwise30kg/ha ear fertilizer and granulated fertilizer caused overmuch nitrogen fertilizer in the later stage of rice and affected the yield(4)Film unraveling nitrogen fertilizing under film mulching cultivation effectively improved nitrogen uptake and utilization efficiency in the later stage of rice growth. In the same rate of nitrogen fertilizing,top dressing nitrogen twice caused the highest nitrogen absorption amount of rice,especially the nitrogen absorption amount of up-ground part were the highest,namely93.66kg/ha,nitrogen absorption and utilization rate were increased by10%and more comparing to all in base fertilizing in one time treatment.The nitrogen absorption amount of up-ground part between the firsttop dressing and the second top dressing treatment were insignificant different.Obviously, yield and nitrogen absorption and utilization rate were increased in different paddy soil in the hilly area of central Sichuan by film mulching.To reduce nitrogen by1/3to120kg/ha even improved the yield and nitrogen utilization efficiency of rice in different paddy soil in film mulching;Unraveling film in medium stage under film mulching cultivation improved the film recovery rate, reduced the white pollution; Fertilizing in the medium and later stage could effectively relieve the burden of fertilizer removal in the later stage, promoted the rice growth. After preliminary study found the optimal supplemental proportion of base fertilizer and dress fertilizer was2:1,namely base fertilizer120kg/ha,ear fertilizer60kg/ha.