滴灌冬小麦地上部干物质积累与分配模型

Study on the accumulation and distribution model of winter wheat above ground dry matter under drip irrigation

关键词:  滴灌  冬小麦  干物质积累  分配指数  模型

Key words:  drip irrigation  winter wheat  dry matter accumulation  partitioning index  model

摘要:

为构建新疆维吾尔自治区南疆滴灌冬小麦地上部干物质积累规律及其分配模型，通过分析氮素调控的小区试验数据，采用统计模型技术建立基于相对生长度日（RDDT）的冬小麦群体和个体地上部相对干物质积累（RDMA）动态和基于分配指数的各器官物质分配动态的模拟模型，运用水分调控试验数据对模型进行检验。结果表明：滴灌冬小麦返青后干物质积累（DMA）呈典型的"S"型曲线变化趋势，增加水和氮供应量明显促进群体和个体干物质积累量，且灌水效应大于施氮效应，说明在塔里木盆地西北边缘的极端干旱地区保证水分供应的基础上适当增施氮肥是促进小麦生长的关键。各处理DMA的变异系数群体为3.45%~5.19%，个体为2.03%~3.91%，表明群体效应大于个体效应。筛选并构建基于归一化的返青后以RDDT为变量的滴灌冬小麦群、个体RDMA预测模型（MMF）：GRDMA_i=（0.001 2+1.003 2RDDT^{4.193 6}）/（0.012 9+RDDT^{4.193 6}）和SRDMA_i=（0.001 2+1.011 3RDDT^{4.691 1}）/（0.018 9+RDDT^{4.691 1}），模拟准确度在0.988 4~1.027 4；以及地上部各器官干物质的分配指数模型，模拟准确度为0.977 5~1.035 4，表明基于RDDT和分配指数的冬小麦群、个体干物质积累和分配模型具有较好的预测性和实用性。

Abstract:

The aim of this study was to study the law of aboveground dry matter accumulation and its distribution model of drip irrigation winter wheat in Southern Xinjiang Uighur Autonomous Region.Simulation models of relative dry matter accumulation (RDMA) in winter wheat population and individual aboveground parts based on relative growth degree day (RDDT) and distribution dynamics of organs based on distribution index were established by using statistical model technology based on the experimental data of nitrogen regulation in plots.The model was tested by the experimental data of water regulation.The result showed that:After reviving,the dry matter accumulation (DMA) of winter wheat under drip irrigation showed a typical "S" curve trend.Increasing water and nitrogen supply obviously promoted dry matter accumulation of populations and individuals,and the irrigation effect was greater than nitrogen application effect indicating that proper nitrogen application on the basis of ensuring water supply in extreme arid areas in the Northwest margin of Tarim Basin was the key to promote wheat growth.The variation coefficients of each treatment were 3.45%-5.19% in populations and 2.03%-3.91% in individuals,indicating that the population effect was greater than the individual effect.The effect of irrigation water treatment on group and individual DMA was greater than that of nitrogen application,which indicated that ensuring water supply was the first priority in extreme arid areas.Based on the normalized RDDT,the prediction model (MMF) for winter wheat group and individual RDMA after reviving under drip irrigation:GRDMA_i=(0.001 2+1.003 2RDDT^{4.193 6})/(0.012 9+RDDT^{4.193 6}) and SRDMA_i=(0.001 2+1.011 3RDDT^{4.691 1})/(0.0189+RDDT^{4.691 1}),and distribution index model of dry matter in various organs of the above-ground part were established,whose simulation accuracy being 0.988 5-1.027 04 and 0.977 5-1.035 4,respectively.These results showed that the model of dry matter accumulation and distribution in winter wheat populations and individuals based on RDDT and distribution index had good predictability and practicability.