膜下滴灌棉花根系吸水模型的建立

Modeling Water Uptake by Cotton Roots with Drip Irrigation Under Mulch Film

通过田间试验,建立了实用性膜下滴灌棉花根系吸水模型,研究了在作物生长条件下的土壤水分运动,以揭示膜下滴灌棉花根系吸水规律。调查了不同生育期膜下滴灌棉花根系的分布,在棉花宽行及窄行采用根钻取样,将土样冲洗后,测定棉花根长参数,进而建立了棉花根长密度分布函数。根据理论分析和计算,考虑根长密度、土壤含水率及植株蒸腾量,建立了棉花根系一维吸水模型,其形式简单,涉及的参数较少。建立的棉花根系一维吸水模型能够反映棉花根系吸水的实际情况,应用方便,具有实际应用价值。

In the present study,the model for cotton-root water uptake with drip-irrigation under mulch film was established based on field experiment.With the model,water dynamics and redistribution was addressed under the condition of cultivation.The fundamental mechanisms of water uptake by cotton roots were carefully discussed.Core samples were collected by drilling separately in wide rows and narrow rows of cotton plants,and the root samples were then separated by water from the soil cores for measuring root lengths.Based on the root lengths,a distribution model was developed regarding root length density of cotton.Based on theoretic analysis and mathematical calculation,one-dimensional cotton root uptake model was built by incorporating factors such as root length density,soil moisture content and plant evaporation.The model had a simple structure with only a few parameters.The cotton root uptake model matched well with field observation and is readily to be applied.