不同施氮水平对春玉米伟科702干物质积累及转运的影响

Effects of Different Nitrogen Levels on Dry Matter Accumulation and Transportation of Spring Maize Weike 702

为进一步推进玉米的减肥增效,以内蒙古西辽河平原主推玉米品种伟科702为供试材料,采用田间试验方法,在0,210,300,390 kg/hm^24个施氮水平下,研究春玉米干物质积累、转运和氮肥利用率的差异性,以期为该品种确定适宜的施氮水平提供理论参考。结果表明,吐丝期之前,干物质积累量随施氮水平的增加而提高;吐丝期之后干物质积累量施氮300 kg/hm^2较施氮390 kg/hm^2更大,干物质积累的最大速率也出现在300 kg/hm^2施氮水平。从完熟期物质积累的构成来看,茎和苞叶以施氮390 kg/hm^2处理最大,而穗轴和籽粒则以施氮300 kg/hm^2最大。随施氮水平的提高,同化物转运量、转运速率和对籽粒贡献率总体上呈增加趋势,但不同器官之间存在明显差异。茎、穗转运贡献率随施氮水平的增加呈先升后降的趋势,以300 kg/hm^2处理最高;叶转运贡献率随施氮水平的增加而增加,以390kg/hm^2处理最高。籽粒产量、经济系数和氮肥农学利用率均以300 kg/hm^2施氮水平最大。在试验地区,300 kg/hm^2施氮水平为春玉米伟科702高产栽培适宜的施氮水平。

For the further promotion of fertilizer loss efficiency in maize,taking the original variety Weike 702 as tested materials in Inner Mongolia West Liaohe Plain,using field test method in 0,210,300 and 390 kg/ha under the four nitrogen levels,differences on dry matter accumulation,transportation and nitrogen fertilizer utilization rate,in order to determine the suitable nitrogen level and provide theoretical reference for the variety. The results showed that before silking stage,dry matter accumulation increased with the increased of nitrogen fertilizer; after silking stage,dry matter accumulation of 300 kg/ha was more than 390 kg/ha,dry matter accumulation of maximum rate also appeared in 300 kg/ha nitrogen level. From the composition of dry matter accumulation in full ripe stage,stems and bracts under the nitrogen level of 390 kg/ha reached the maximum,and cob and grain in 300 kg/ha reached the maximum. With the increased of nitrogen application levels,the amount of assimilation transportation,transportation rate and the contribution rate to grain showed an increasing trend,but there were significant differences among different organs. The transportation rate of stem and spike increased first and then decreased with the increased of nitrogen application levels,the highest in 300 kg/ha treatment,leaf transportation rate increased with the increased of nitrogen application,which was the highest in 390 kg/ha treatment. The grain yield,economic coefficient and the agronomic efficiency of nitrogen fertilizer were highest at 300 kg/ha nitrogen level. In the study area,the level of nitrogen application of 300 kg/ha was the suitable nitrogen application level in the high yield cultivation of springmaize Weike 702.