施氮量对冬小麦氮素利用和产量的影响

Effect of Nitrogen Application Rate on Nitrogen Utilization and Grain Yield of Winter Wheat

为给限量灌溉条件下冬小麦高产栽培中合理施氮提供依据,2008-2009年度分别在藁城市和清苑县以冀5265和科农199为材料,研究了限量灌溉条件下(小麦全生育期灌3水,每次灌水量75mm)施氮量(0、120、180、240和300kg·hm-2,分别用N0、N120、N180、N240和N300表示)对冬小麦氮素吸收利用及小麦产量的影响。结果表明,增施氮肥有利于增加小麦植株和籽粒的含氮量和氮素积累总量。随施氮量的增加,藁城点籽粒氮素积累量呈持续增加趋势,清苑点在N240处理下籽粒中氮素积累量达到最高后开始下降。两地试验中氮素干物质生产效率均随施氮量的增加而降低,藁城的氮素生产效率、回收效率及农艺效率呈先升高后降低的趋势,以N180的氮素生产效率最高,回收效率和农艺效率则以N240最高;穗数和穗粒数随施氮量的增加而增大,千粒重随施氮量的增加而降低,且各处理间差异显著;籽粒产量随施氮量增加呈递增趋势,但N240与N300之间差异不显著。清苑县的试验中,氮素干物质生产效率、籽粒生产效率、回收效率和农艺效率都随施氮量的增加而降低,且在部分处理之间差异显著;穗数、穗粒数和籽粒产量均以N240的最高,千粒重则以N0的最高,再增加施氮量反而使产量及其构成因素有所降低。根据本研究结果,在河北平原限量灌溉条件下,小麦生产中施氮240kg·hm-2可以获得较理想的籽粒产量和氮素利用效率。

In order to clarify the effects of nitrogen application rate on nitrogen utilization and grain yield under limited irrigation,field experiments were carried out during 2008-2009 in Gaocheng and Qingyuan with local commercial winter wheat cultivar Ji 5265 and Kenong 199,respectively.The experiments were all designed as randomized block arrangement,with the application rates of N 0,120,180,240 and 300 kg·hm-2,respectively,indicated as N0,N120,N180,N240 and N300,respectively,under limited irrigations（three irrigations of 75 mm during the growing period）.The results showed that,with the increase of nitrogen application amount,the contents and accumulation amounts of nitrogen in wheat plants and grains increased.The nitrogen accumulation in grain was all increased with the amount increasing of nitrogen application,with the accumulation amount of the treatment N300 was the highest in Gaocheng,but that of N240 was the highest in Qingyuan.The nitrogen dry matter production efficiencies decreased with the amount increasing of nitrogen application in both Gaocheng and Qingyuan.In Gaocheng＇s experiment,the grain production efficiency,recovery efficiency and agronomic efficiency of nitrogen all increased with the increase of nitrogen application amount,and reached the peak of nitrogen production efficiency for N180,and those of nitrogen recovery efficiency and agronomic efficiency for N240,then decreased.The spikes per hectare and grains per spike increased,but grain weight significantly decreased with the increase of nitrogen application amount.The grain yield also increased with the amount increasing of nitrogen application,although the difference in grain yield was statistically insignificant between N240 and N300.In Qingyuan＇s experiment,the dry matter production efficiency,grain production efficiency,recovery efficiency and agronomic efficiency of nitrogen were all decreased with the amount increasing of nitrogen application,and the difference among different treatments were significant.The highest values of spikes per hectare,grains per spike and grain yield were all achieved for N240,but the grain weight of N0 was the highest,and decreased with the increase of nitrogen application amount.According to the results,it is recommended that application of 240 kg·hm-2 N for satisfactory grain yield and nitrogen use efficiency of winter wheat under limited irrigation in Hebei Plain of China.