Effects Of Different Application Nitrogen At Middle Growth Stage On Machine-transplanted Rice Yield,the Absorption And Utilization Of N And Rice Quality

The experiment was conducted in the outside experimental base of agricultural college of Yangzhou university during 2014 to 2015,taking the rice Yongyou2640,and the rice Wuyunjing24 and Nanjing9108 as materials,designing 5 kinds of nitrogen management amount and method mode.A1 is the control(300Nkg/hm2,base:tillering:end of active tillering:spikelet-promoting fertilizer:spikelet-developing frtilizer=120:90:0:60:30)and B1(300Nkg/hm2,60:0:90:90:60),C1(300Nkg/hm2,0:0:120:120:60),B2(240Nkg/hm2,60:0:90:90:0),C2(240Nkg/hm2,0:0:90:90:60)are the other treatments.The experiment simulated blanket seeding machine-transplanting.On this basis,we studied the effects of different application nitrogen at middle growth stage on machine-transplanted rice yield,the absorption and utilization of N and rice quality.All of these are aimed to promote high-efficiency nitrogen application for local blanket seeding machine-transplanting rice planting.The main results are as follows:1.Different application nitrogen at middle growth stage on machine-transplanted rice has yield-increasing production which is expressed in the number of tillers per stem and the number of grains per panicle.In the nitrogen treatment(300Nkg/hm2)of Yongyou 2640 and Nanjing 9108,the yield of B1 is the highest,which in the Wuyunjing 24 the highest is C1.The yield advantage are caused by higher number of stems and tillers,and total spikelets is the best.From heading to mature stage;the dry matter accumulation and population growth rate are consistent with yield.The yield of the treatment(240Nkg/hm2)was B2>C2,the yield differences in tiller number and grain number per panicle significantly higher than that of C2,so the final yield and total amount of spikelets is higher;From heading to mature stage,the dry matter accumulation and the population growth rate is B2>C2.Therefore,in the nitrogen treatments(300Nkg/hm2),the yield is different in different varieties.The performance of B2 is better than that under different nitrogen treatments.2.The nitrogen content and nitrogen uptake of B and C in main growth stages are significantly higher than A1.The highest nitrogen uptake in mature period is B2.The nitrogen uptake and utilization efficiency,agronomic nitrogen use efficiency and partial fertilizer productivity under the 240 kg/hm2N application are higher than under the 300 kg/hm2 nitrogen application.In the same application levels of nitrogen,The nitrogen uptake and utilization efficiency,agronomic nitrogen use efficiency and partial fertilizer productivity of B are higher than C and A1.The N stage uptake of Yongyou2640 is highest before jointing stage in different processing,but the highest stage uptake of conventional rice is from jointing to heading stage.Compared with A1,B and C increased nitrogen uptake before jointing stage and heading to maturation stage.The nitrogen uptake and utilization efficiency,agronomic nitrogen use efficiency and partial fertilizer productivity of B2 is highest and significantly higher than other processing.Therefore,the nitrogen uptake of B and C in earlier and late growth stage are higher than A1 and the N absorption ratio in middle growth stage are below A1.The N absorption rate of B and C are higher than A1 in each stage.The nitrogen uptake and utilization efficiency of B2 is highest.3.The processing of B and C decreased the processing quality of rice.The brown rice rate,milled rice rate and head rice rate of A1 is highest and the other four processing are slightly lower.In the cooking and eating quality,the amylose contents of B and C in Yongyou2640 are higher than A1 and it is opposite in conventional rice.In the nutritional quality,the protein content of B and C somewhat increased compared with A1.The chalky rice rate and chalkiness present the result of A1>B>C,shows that the processing of B and C will result debase the appearance quality of the rice.The difference between the processing in Yongyou2640 was not significant.But it has a big difference in conventional rice.Especially in the C processing,the chalky rice rate and chalkiness is very high.The peak viscosity,hot viscosity,breakdown and final viscosity of B2 is highest in Yongyou2640 and Wuyunjing24 and present that B>Al>C.It presents that B>C>A1 in setback.There is no obvious regularity in five processing of Nanjing9108.The peak time and pasting temperature has no significant difference.