Effects Of Total Straw Returning And Nitrogen Application On Grain Yield?Nutrient Absorption And Quality Of Mechanical Transplanted Japonica Rice With Good Taste Quality

The field experiments were conducted in Changshu institute of agriculture science,Jiangsu Province at Taihu region in 2014?2015,the preceding crop is wheat.Two Conventional early-maturing late japonica(CEMLJ)rice cultivars with good taste quality in Jiangsu,Nanjing 5055 and Nanjing 46,were adopted as materials,Straw returning was two ways of returning total straw to field(the amount of wheat straw was 6.0 t hm-2)and straw without returning;Set 6 kinds of base-tiller nitrogen fertilizer and earing fertilizer applications in proportion of 9:1,8:2,7:3,6:4,5:5 and 4:6.In order to study the influence of total straw returning and different nitrogen application on the yield?Nutrient absorption characteristics and quality of mechanical transplanted japonica rice with good taste quality.The main results were as follows:1.The yield was significantly affected by total straw returning as compared with non-application of straw,that of Nanjing 5055 and Nanjing 46 increased by 5.04%and 4.64%reapectirely.The yield of machine transplanted japonica rice with straw returned to the field first increased and then decreased with decreasing basal-tillering-fertilizer proportion,and the treatment with 7:3 of basal-tillering/panicle fertilizer ratio had the highest yield.With the same nitrogen application,dry matter accumulation of total straw returning treatment was lower than that of the control during the elongation stage and the transplantation to elongation stage,but higher at heading stage,mature stage,elongation to heading stage and heading to maturity stage.With the decrease of basal-tillering-fertilizer proportion,dry matter accumulation was decreased at elongation stage and transplantation to elongation stage,but first increased and then decreased during the heading,mature,elongation to heading and heading to maturity stages.In the treatment of 7:3 of basal-tillering/panicle fertilizer ratio,the dry matter accumulation,and economic coefficient were the highest in whole straw returning treatment.2.In the whole straw returning treatment,compared with the control,the nitrogen accumulation was lower before elongation,but higher at elongation to heading and heading to maturity stages.In addition,the nitrogen apparent efficiency,nitrogen agronomic efficiency and nitrogen partial factor productivity were also higher than thase of the treatment without straw application.In different nitrogen fertilizer applications,with the decrease of basal-tillering-fertilizer proportion,the nitrogen apparent efficiency,nitrogen agronomic efficiency,nitrogen physiological efficiency and nitrogen partial factor productivity were first increased and then decreased,reaching the highest point when the application proportion of base-tiller nitrogen fertilizer to earing nitrogen fertilizer was 7:3.In the whole straw returning treatment,the accumulation and absorption rate of P and K in each growth stage were significantly higher than those of on straw.Different nitrogen application treatments have obvious effects on P,K absorption,accumulation and absorption rate.In the treatment of 7:3 of basal-tillering/panicle fertilizer ratio,the absorption rate and accumulation of P and K were the highest in whole straw returning treatment.3.The total amount of straw returned to the field significantly increased the protein content of rice,the chalkiness rate,chalkiness and chalkiness were decreased,at the same time,improved appearance quality and nutritional quality of rice.The total amount of straw returned to the field is also conducive to the improvement of cooking and eating quality,the results showed that the breakdown value of rice and the taste value were significantly improved,but the setback value was significantly reduced.In the aspect of nitrogen application,increase the ratio of panicle to total N application,can significantly improve the processing and nutritional quality of rice,improve the whole milled rice rate,but at the same time increase the rice chalkiness,reduce the appearance quality of rice,and the cooking and eating quality of rice also declined.