揭膜时期和施氮量对陇东旱塬春玉米群体生理指标及产量的影响

摘要

Field experiments were carried out to identity the optimum uncovering plastics film period and nitrogen amount for higher yield and better growth index of spring maize under the plastic-covered ridge and furrow planting in Loess Plateau of East Gansu. Three uncovering plastics film periods ( uncovering plastics film at jointing stage, uncovering plastics film at teaseling stage and mulching plastics film for whole growth stage) and three nitrogen amount (N 0, 150, 225 kg/hm2) were applied to study the interaction between uncovering plastics film period and nitrogen amount on growth and yield of spring maize. The re-sults showed that the effects of uncovering period or applied amount of nitrogen on the yield reached significant or extremely sig-nificant difference, while their interaction was not significant. The yield and water use efficiency of uncovering plastics film of teaseling stage were the best among all the treatments. There was no significant for the yield of spring maize between the treat-ments of uncovering plastics film at jointing stage and mulching plastics film of whole growth stage. The spring maize yield was extremely significant higher for applying nitrogen ( high or low nitrogen ) treatments than those of no nitrogen fertilizer treat-ments, and yield increased with the increasing of nitrogen application amount. Compared with low nitrogen treatment, the yield was increased in a certain degree for applying high nitrogen treatments, but the difference was not significant. The maize leaf SPAD value, photosynthetic rate and leaf area index were much better with higher nitrogen and uncovering plastics film of teaseling stage. Considering yield, water use efficiency and growth index, uncovering plastics film of teaseling stage combined with nitrogen application amount of 150~225 kg/hm2 was a most suitable cultivation mode under Ridge and Furrow Planting in Loess Plateau of East Gansu.%为了探明甘肃陇东旱塬区全膜双垄沟播玉米产量、生长指标同步提高的适宜揭膜时期和施氮量，本研究以甘肃陇东旱塬全膜双垄沟播春玉米为研究对象，设置了3个揭膜时期(拔节期揭膜、抽雄期揭膜、全生育期覆膜)和3个施氮量( N 0、150、225 kg/hm2)，研究了揭膜时期、施氮量及其互作对春玉米生长指标及产量的影响。结果表明：揭膜时期或施氮量对玉米产量影响差异达显著或极显著水平，而其互作不显著。抽雄期揭膜籽粒产量和水分利用效率均优于拔节期揭膜和全生育期覆膜，而拔节期揭膜与全生育期覆膜之间产量差异不显著。同一揭膜时期，施氮(高氮或低氮)玉米产量极显著高于不施氮，且产量随施氮量的增加而增加。与低氮处理相比较，高氮处理玉米产量虽有一定程度的增加，但差异不显著。同时，抽雄期揭膜结合高施氮量较低施氮量更有利于玉米叶片SPAD值、光合速率及叶面积指数等生长指标的改善。因此，综合考虑产量、水分利用效率及生长指标，在甘肃陇东旱塬区全膜双垄沟播玉米栽培条件下，抽雄期揭膜结合施氮量150~225 kg/hm2为较适宜的栽培模式。