小麦根长密度和根干重密度对氮肥的响应及其与产量的关系

Responses of Root Length Density and Root Dry Weight Density to Nitrogen Fertilizer and Their Relationship with Yield in Wheat

为总结施氮量与小麦根系生长及产量的关系,通过查询近30年(1993-2019年)中国主要麦区施氮量对小麦根长密度、根干重密度及产量影响的文献资料,对小麦适宜的施氮范围进行分析。结果表明,随着土层的加深,小麦根长密度(RLD)和根干重密度(RDWD)总体上呈逐渐降低的趋势,且小麦根系主要分布在0~20cm土层。不同施氮量下0~60cm土层小麦开花期的RLD和RDWD均高于成熟期,开花期的RLD和RDWD分别在施氮220~235和192~209kg·hm^-2时达到最大值,成熟期分别在施氮220~275和171~212kg·hm^-2达到最大值。经相关性分析,小麦产量与RLD、RDWD均呈显著正相关。通过对施氮量与小麦籽粒产量进行一元二次方程拟合得出,在施氮量为247kg·hm^-2时小麦产量达到峰值。因此,在当前中国主要麦区向农户推荐氮肥用量时,需针对不同区域,结合农田实际,在施氮171~247kg·hm^-2范围选择合理用量,以促进小麦根系的生长发育及籽粒产量的提高。

In order to summarize the relationship between nitrogen application rate and root growth and yield of wheat,the effects of nitrogen application on root length density and root dry weight density and their relationship with yield of wheat were studied by consulting relevant literature in major wheat production regions of China during1993-2019.The results showed that root length density(RLD)and root dry weight density(RDWD)decreased with the increase of soil layer in 0-60 cm,especially in 0-20 cm soil layer.The RLD and RDWD values were higher at anthesis than that at maturity stage of wheat,and the RLD and RDWD reached maximum values at anthesis with nitrogen application 220-235 kg·hm^-2 and 192-209 kg·hm^-2 and at maturity stage with nitrogen range of 220-275 kg·hm^-2 and 171-212 kg·hm^-2,respectively.The correlation analysis also showed that wheat yield significantly positively related with the RLD and RDWD.In addition,wheat yield increased with the increase of nitrogen application rate,and reached maximum values at 247 kg·hm^-2 nitrogen application.Therefore,in order to promote the growth and development of wheat root system and to increase the grain yield,it is necessary to select a reasonable amount of nitrogen within the range of 171-247 kg·hm^-2 according to different regions and the actual situation of farmland.