拔节期追氮对鲜食糯玉米产量和花后养分积累转运的影响

以苏玉糯5号和渝糯7号为材料,2013～2016年于扬州大学实验农场研究拔节期追氮量(0、150、300 kg/hm2)对鲜食糯玉米产量(鲜果穗和鲜子粒)、干物质和氮素积累和转运的影响。结果表明,鲜食糯玉米子粒产量和果穗产量均随追氮量的增加呈先升后降趋势,在追氮150 kg/hm2时产量最高。干物质和氮素积累量随着追氮量的增加表现趋势与产量一致。氮素利用率以子粒作为收获产品时随追氮量增加逐渐降低,以果穗作为收获产品时,在150和300 kg/hm2时无显著差异,低于不追氮处理。在鲜食糯玉米生产中,拔节期适量追氮150 kg/hm2可有效增加鲜食糯玉米产量、后期干物质和氮素积累量以及氮素利用效率,提高产量的同时降低环境风险。

Effects of N Topdressing at Jointing Stage on Yield and Post-flowering Nutrient Accumulation and Translocation in Fresh Waxy Maize

The effects of N rates(0, 150 and 300 kg/ha) of topdressing at jointing stage on the fresh waxy maize yield(ear and grain) as well as the accumulation and translocation of dry matter and N post-flowering were studied using the control varieties in south China(Suyunuo 5 and Yunuo 7) as materials at Yangzhou experimental farm, Jiangsu, China in 2013-2016. The fresh waxy maize ear and grain yield rose first and fall later and peaked at 150 N kg/ha. The change tends of dry matter and N accumulation under different N rates was similar to yield. The N use efficiency gradually reduced with the increase of N rates when the harvest product was grain, while the value was similar between N rates 150 kg/ha and 300 kg/ha and lower at N0 when the harvest product was ear. So, in fresh waxy maize production, the appropriate N topdressing at jointing stage was about 150 kg/ha, which increased the yield of fresh waxy maize(ear or grain) as well as the dry matter and N accumulation post-flowering, ultimately increased the yield and reduced environmental risks.