基于彭曼公式的膜下滴灌棉田灌水量研究

Study on the Irrigation Water Amount under Film Mulch Drip Irrigation according to Penman-Monteith Formula

【目的】探讨基于彭曼公式,膜下滴灌棉田不同灌溉量对棉花生长的影响。【方法】基于彭曼公式,设计一定梯度的灌溉处理,结合气象数据和土壤墒情,进行小区试验,分析干物质积累、水分消耗的变化规律,研究干物质积累、产量与耗水量的关系。【结果】棉花各生育时期干物质积累趋势符合"S"型变化规律;基于彭曼公式推荐灌溉量下的土壤储水量基本上处于棉花各个生育期需水的适宜状态,在未对棉花生长造成胁迫的前提下,对土壤水分利用充分,起到了节水的作用;棉田日蒸散量在整个生育时期呈现"低-高-低"的趋势;从干物质日积累和日耗水量拟合结果来看,其R2=0.857 8,说明两者之间具有显著的相关性;建立了籽棉产量与灌溉量的回归模型:Y=-0.010 8 X2+7.906 9 X-1 029.9(R2=0.926 2)。【结论】以彭曼公式为理论指导膜下滴灌棉花的灌溉量,基本符合棉花各个生育时期的需水规律。

【Objective】 The purpose of this project was to explore the influence of different irrigation water amounts on cotton growth and yield under film mulch drip irrigation basing on Penman-Monteith formula.【Method】Basing on Penman-Monteith formula,a plot experiment was carried out according to a certain gradient of the irrigation amount combining with meteorological data and soil moisture to analyze the changing regularity of dry matter accumulation,water consumption,and discuss the relationship among dry matter accumulation,yield and water consumption.【Result】 Dry matter accumulation of cotton in different growth stages complies with the ＂S＂ type changing regularity.The soil moisture content is basically at the suitable condition of water requirement in each cotton growth stage according to the recommend irrigation water amount basing on Penman-Monteith formula,and soil moisture was fully made use of and the goal of water-saving without influencing cotton growth was achieved.The daily average transpiration of cotton presented ＂low-high-low＂ tendency in the whole growth stage.The fitting result of dry matter accumulation and water consumption（R2=0.857 8） showed that there was a significant correlation between them.The regression model was established with seed cotton yield（Y） and irrigation amount（X）： Y =-0.010 8 X2 ＋ 7.906 9 X-1 029.9（R2 = 0.926 2）.【Conclusion】 The irrigation amount based on the theory of Penman formula basically met the cotton water requirement of each growth stage.