氮肥用量对棉花生长发育及产量的影响

Effects of Nitrogen Fertilizer Amount on Cotton Growth and Economic Benefits

采用双因素裂区大田试验设计,探究适宜于东疆哈密地区棉花高产低投的氮肥施用量,以品种为主区,选用‘新陆中46’和‘新陆中67’两个品种,氮肥用量为副区,设置0、90、180、270、360、450 kg/hm^26个施氮水平(纯氮),分析不同品种棉花施氮水平对其农艺性状、棉铃时空分布及产量的影响。结果表明,两品种棉花各项指标间均存在不同程度的差异,主要表现为‘新陆中67’的结铃性更强,对氮肥用量变化的响应一致,表现为株高、茎粗、果枝数、叶枝数均随氮肥用量的增加而增大,施氮量超过360 kg/hm^2后,氮肥对各指标无影响,两品种均以伏桃占比最高,伏桃个数、籽棉产量均在施肥量为270 kg/hm^2时达到最大,分别为5.91、6.71个和6201.65、6365.79 kg/hm^2;模拟寻优得出‘新陆中46’和‘新陆中67’籽棉产量最佳施氮量分别为298.18、288.72 kg/hm^2,符合本试验实测结果;‘新陆中46’和‘新陆中67’经济效益最佳施氮量分别为287.11、270.80 kg/hm^2,而180 kg/hm^2施氮水平下,两品种棉花皮棉产量最高为2802.56、2831.36 kg/hm^2,同时也能保证较高籽棉产量。本试验条件下,氮肥用量在270~300 kg/hm^2可获得最高的籽棉产量和经济效益,分别达6300.00 kg/hm^2和25000.00元/hm^2;该地区有很大的减氮潜力,可以180 kg/hm^2氮肥用量作为减氮的最低标准线。

To explore the application of nitrogen fertilizer suitable for high yield and low investment of cotton in Hami region of eastern Xinjiang and provide technical guidance for reducing nitrogen fertilizer application in cotton in this region by a two-factor split zone test design.The main area was the two varieties,‘Xinluzhong 46’and‘Xinluzhong 67’,and the other area where nitrogen fertilizer was used was taken as the auxiliary zone.Here,0,90,180,270,360 and 450 kg/hm^2 of six nitrogen application levels(pure nitrogen)were set to analyze the effects of different nitrogen application levels on the agronomic traits,space-time distribution of cotton bolls,and yield of different cotton varieties.The results showed that there were different degrees of differences between the two cotton cultivars.The main manifestation was that‘Xinluzhong 67’had stronger bolliness,and the response to changes in nitrogen fertilizer application was consistent,including plant height,stem diameter,and fruit branch.The number of leaves and branches increased with the increase of nitrogen fertilizer application.After exceeding 360 kg/hm^2,nitrogen fertilizer had no effect on each index.Both varieties had the highest proportion of futao,and when the number of futao and seed cotton yield were 270 kg/hm^2,they reached the maximum,which were 5.91,6.71 and6201.65 kg/hm^2,6363.79 kg/hm^2,respectively;The optimal nitrogen application amount for seed cotton yield of‘Xinluzhong 46’and‘Xinluzhong 67’were obtained by simulation and optimization,respectively.They were 298.18 kg/hm^2 and 288.72 kg/hm^2,which was consistent with the results of this experiment.The best economic benefits of nitrogen in‘Xinluzhong 46’and‘Xinluzhong 67’were 287.11 kg/hm^2 and270.80 kg/hm^2,respectively.Under the nitrogen application level of 180 kg/hm^2,the cotton lint yields of the two varieties were up to 2802.56 kg/hm^2 and 2831.36 kg/hm^2,and meanwhile,higher seed cotton yields were also guaranteed.Under this experiment condition,the highest nitrogen seed fertilizer yield and economic benefits could be obtained when the nitrogen fertilizer dosage was 270-300 kg/hm^2,reaching6300.00 kg/hm^2 and 25000.00 yuan/hm^2 respectively;the region had great nitrogen reduction potential,namely,the amount of nitrogen fertilizer 180 kg/hm^2 could be used as the minimum standard line for nitrogen reduction.