秸秆还田与氮肥配施对常规晚粳稻产量、氮素累积转运及利用效率的影响

为明确秸秆全量还田条件下浙北地区常规晚粳稻适宜的施氮量,设计秸秆全量还田条件下N0、N1、N2和N34个氮肥用量的田间试验(肥料N用量分别为0、165、240、315 kg/hm₂)。结果表明:秸秆全量还田条件下,常规晚粳稻单位面积产量随着氮肥用量的增加呈增长趋势,秀水134和嘉58施氮处理比无氮处理(N0)分别增产31.41%~45.38%、39.97%~47.83%,高氮处理(315 kg/hm₂)比中氮处理(240 kg/hm₂)分别增产3.60%和5.62%,但差异不显著;当氮肥用量达315 kg/hm₂时,常规晚粳稻的结实率、千粒质量均低于其他处理。随着施氮量的增加,秀水134和嘉58齐穗期后的群体干物质量累积和氮素累积呈上升趋势,但群体氮素转运量先增加后降低,群体氮素转运效率整体呈下降趋势。总之,高氮处理(315 kg/hm₂)氮素转运量较少,转运效率较低,同时氮素利用效率和吸收效率也较低。因此,秸秆还田条件下合理配施中量氮肥,可以获得较高水稻产量和氮肥利用率。

Effects of Rice Straw Incorporation and Nitrogen Fertilization on the Yield,Nitrogen Accumulation and Translocation,and Nitrogen Use Efficiency of Conventional Late Geng Rice

This study aimed to determine the appropriate nitrogen application rate for conventional late Geng rice under the condition of incorporating the full amount of rice straws into the soil in northern Zhejiang Province.With rice straws fully returned to the soil,four nitrogen fertilization treatments were set as follows:N0,no nitrogen application;N1,165 kg/hm₂;N2,240 kg/hm₂;N3,315 kg/hm₂.The results showed that rice yield rose with increasing nitrogen application rate.Treatments with varying nitrogen application rates increased the yields of the late Geng rice varieties Xiushui 134 and Jia 58 by 31.41%~45.38%and 39.97%~47.83%,respectively,compared with N0;the yields of Xiushui 134 and Jia 58 treated with the high nitrogen application rate(315 kg/hm₂)were 3.60%and 5.62%higher than those treated with the moderate nitrogen application(240 kg/hm₂),but the differences were not significant.When the nitrogen application rate was at 315 kg/hm₂,the seed setting rate and 1000 grain weight of rice were lower than those of the other treatments.The dry matter accumulation and nitrogen accumulation of Xiushui 134 and Jia 58 increased with rising nitrogen application rate,but the nitrogen translocation efficiency first increased and then decreased,and the nitrogen translocation efficiency of Xiushui 134 and Jia 58 overall dropped with rising nitrogen application rate.In a word,the treatment with the high nitrogen application rate(315 kg/hm₂)had less nitrogen translocation,lower translocation efficiency,and lower efficiency of nitrogen use and absorption.Hence,under the condition of returning the full amount of straws to the soil,application of nitrogen fertilizer at a moderate level can improve rice yield and nitrogen use efficiency.