精细化水氮调控对膜下滴灌棉花冠层特性动态变化影响

目的]通过高产棉花冠层调控来完善棉花水肥高效管理技术理论.方法]采用田间膜下滴灌方式,在相对高、低两个灌溉量下,设等施氮下5个不同氮肥运筹方案,完全组合共10个处理,测定分析10个处理下棉花生育期冠层特性和产量的变化特征.结果]无论灌溉量高低,在蕾期"前重后轻"施氮水平的叶面积指数、消光系数均显著高于"前轻后重"施氮水平;在花期高灌溉量下,"前重后轻"施氮水平的叶面积指数显著高于"前轻后重"施氮水平;蕾、花、铃期高灌溉量下"前重后轻"施氮水平的叶面积指数均增加相对较快,随着"前重后轻"施氮水平的加重,散射辐射透过系数、直射辐射透过系数则减少相对较快;蕾、花、铃期低灌溉量下"前轻后重"施氮水平的平均叶簇倾斜角度降低相对较快,而消光系数则增加相对较快;灌溉量较高时,精细化水氮调控下产量随叶面积指数呈线性正相关变化,"前重后轻"施氮水平的叶面积指数和籽棉产量显著高于"前轻后重"施氮水平.结论]灌溉量相对较高时,两次追肥时采用"前重后轻"施氮策略的棉花叶面积指数在蕾期、花期表现出最高值,并对生育期的叶面积指数、散射辐射透过系数、直射辐射透过系数、消光系数、产量的影响作用强于"前轻后重"的施氮策略.

Change of Cotton Canopy Characteristics Resulted from Intensive Water and Nitrogen Regulation under Film Drip Irrigation

【Objective】To improve cotton planting technology according to cotton canopy characteristics.【Method】Adopt the way,in film with drip irrigation relatively high and low two irrigation quantities,design such 5 different nitrogen strategy plan,completely combination of 10 treatments,determine and analyze the 10 with cotton canopy characteristic and yield growth the variation characteristics.【Result】whether irrigation level is high or low,LAI value and K value each of them with "behind the front less" application of N fertilizer was significantly higher in the bud stage;In the bloom stage under the high irrigation,LAI value was significantly higher with "behind the front less" application of N fertilizer;in the Bud stage,bloom stage,boll stage under high irrigation,with "behind the front less "application of N fertilizer,LAI value was relatively fast increased,but the TC value and T value were decreased relatively quickly;in the bud stage,bloom stage,boll stage under low irrigation,MFIA value was decreased relatively quickly with "front behind much less" application of N fertilizer,but the K value was increased relatively quickly;when the irrigation is higher,the fine under the control of water and nitrogen yield with LAI value was positively related to change,LAI value and seed cotton yield each of them with "behind the front less"application of N fertilizer was significantly higher 【Conclusion】when the Irrigation is relatively high,the LAI of cotton in bud stage and bloom stage showed the highest value when using two top-dressing with the"behind the front less"strategy of nitrogen,to the effect of LAI value,TC value,T value,K value,and yield in growth stage was stronger than that "front behind much less" strategy of nitrogen.