东北黑土区膜下滴灌施氮管理对玉米生长和产量的影响

Effects of nitrogen management on the growth and yield of mulched and drip-irrigated maize in Northeast Black Soil Regions

2011和2012年在东北黑土区开展了玉米膜下滴灌田间试验，研究生育期滴灌施氮次数与施氮量对玉米生长和产量的影响。施氮次数取1次（拔节期）和3次（拔节期、抽穗期、灌浆期）2个水平，施氮量取50、100、150、200 kg/hm^24个水平。结果表明，施氮次数对玉米的生长和产量影响显著，1次施氮处理显著提高了玉米在生育前期的株高、叶面积指数（LAI）、干物质质量和氮素吸收量，3次施氮处理使生育后期的干物质质量和氮素吸收量显著提高，产量随施氮次数显著增加，平均比1次施氮处理提高5%；施氮量对玉米各生育期株高和LAI的影响均不显著，干物质质量和氮素吸收量随施氮量呈增加趋势，尽管2012年玉米产量随施氮量的增加显著增长，但施氮量对玉米产量的影响明显小于施氮次数。本研究建议东北黑土区玉米膜下滴灌采用3次施氮、施氮量150-200 kg/hm^2的施氮管理措施。

Field experiments were conducted on a black soil in Northeast China to investigate the influenc-es of nitrogen splits and rates in the growing season on the growth and yield of mulched and drip-irrigated maize in 2011 and 2012. In the experiments, a single nitrogen application at the jointing stage and three nitrogen splits at the jointing, heading and filling stages were used. For each nitrogen split, four nitrogen levels of 50, 100, 150 and 200 kg·hm^-2 were tested. The results indicated that the effect of nitrogen splits on maize growth and yield was statistically significant. The single nitrogen application significantly increased the plant height, leaf area index （LAI）, dry matter aboveground and nitrogen uptake of maize in the early growing season. However,the three nitrogen splits in season produced a higher dry matter aboveground and nitrogen uptake in the late growing season. The yield averaged over the treatments using the three nitrogen splits was nearly 5 % greater than the single nitrogen application treatments. The nitrogen rates had an insignificant effect on plant height and LAI during the whole growing season. Nitrogen splits imposed a more important impact on the yield than the nitrogen application rates,although a significant in-crease of yield with the amount of nitrogen applied was observed in 2012. We recommend a management practice of 150-200 kg·hm^-2 of nitrogen applied at three nitrogen splits to obtain high production while reducing the risk of nitrogen leaching for the black soil in Northeast China.