氮肥管理对有序机抛早稻产量及氮素利用的影响OA北大核心CSTPCD

This study investigated the effects of nitrogen fertilizer application rate and distribution on the yield,growth characteristics and nitrogen utilization of ordered machine throwing early rice.Field experiments on conventional early rice variety Xiangzaoxian 24 were conducted from 2021 to 2022 by setting three levels of nitrogen applications,namely N1(120 kg/hm2),N2(150 kg/hm2)and N3(180 kg/hm2),five groups of nitrogen fertilizer allocation ratios of basal fertilizer,tillering fertilizer and panicle fertilizer,T1(1∶1∶1),T2(0∶1∶1),T3(1∶0∶1),T4(1∶1∶0),and the control CK(nitrogen application rate of 120 kg/hm2,the application ratio 5∶3∶2)and zero nitrogen treatment(N0).The results showed that the average yield of early rice with orderer machine throwing decreased sequentially with the decrease of nitrogen application rate,and the average yield of N1 was significantly lower than that of CK and higher than that of N0.The yield of T2 was lower than those of T1,T3,T4 and CK,with a significant decrease compared to T4.Analysis of yield components reveals that the decrease in yield mainly resulted from the decrease in the number of spikes per unit area.The tillering rate of T2 treatment did not significantly decrease,but had low panicle formation rate and decreased panicles per unit area.The nitrogen utilization efficiency of ordered machine throwing early rice decreases when the nitrogen application rate increases.The nitrogen absorption and utilization efficiency,as well as the agronomic utilization efficiency of T2 were significantly lower than those of T4.It could be seen that instead of panicle fertilizer,basal fertilizer with nitrogen fertilizer had a significant impact on the yield and nitrogen utilization efficiency of ordered machine throwing early rice.It could be concluded that nitrogen fertilizer management in the early stage might be a key factor for high yield in ordered machine throwing cultivation of rice.