温室甜瓜营养生长期日蒸腾量估算模型

Estimation model for daily transpiration of greenhouse muskmelon in its vegetative growth period

建立了基于温室环境参数、甜瓜生长发育参数和土壤水分参数的温室甜瓜日蒸腾量估算模型,以研究温室条件下甜瓜蒸腾量的估算方法.根据温室内特定环境对Penman-Monteith方程中空气动力项进行修正,推导出了适于计算温室条件下参考作物蒸腾量的温室环境因子子模型;以甜瓜叶面积指数为自变量构建了作物因子子模型,模型形式为线性函数;以土壤相对有效含水量为自变量构建了土壤水分因子子模型,模型形式为对数函数.采用分期播种法,根据周年不同播期实测数据对模型参数进行估计和分析.采用土壤相对含水量分别为80%、70%、60%的实测蒸腾数据,对模型在充分灌溉和节水灌溉条件下的预测精度进行了检验,模拟值的平均相对误差分别为11.5%、16.2%、16.9%.所建蒸腾模型是对Penman-Monteith公式在温室环境和节水灌溉条件下的有益探索,具有重要推广应用价值.

For developing an estimation method of muskmelon transpiration in greenhouse, an estimation model for the daily transpiration of greenhouse muskmelon in its vegetative growth period was established, based on the greenhouse environmental parameters, muskmelon growth and development parameters, and soil moisture parameters. According to the specific environment in green-house, the item of aerodynamics in Penman-Monteith equation was modified, and the greenhouse environmental sub-model suitable for calculating the reference crop evapotranspiration in greenhouse was deduced. The crop factor sub-model was established with the leaf area index as independent variable, and the form of the model was linear function. The soil moisture sub-model was established with the soil relative effective moisture content as independent variable, and the form of the model was logarithmic function. With interval sowing, the model parameters were estimated and analyzed, according to the measurement data of different sowing dates in a year. The prediction accu- racy of the model for sufficient irrigation and water-saving irrigation was verified, according to measurement data when the relative soil moisture content was 80%, 70%, and 60%, and the mean relative error was 11.5% , 16.2% , and 16.9% respectively. The model was a beneficial exploration for the application of Penman-Monteith equation under greenhouse environment and water-saving ir- rigation, having good application foreground and popularization value.