内蒙古东北部大豆灌溉动态预报模型

为实现内蒙古东北部大豆农田灌溉动态预报,应用多项式拟合方法将大豆适宜土壤湿度下限值插值到全生育期的每一天,形成适宜土壤水分下限动态连续指标曲线,并从土壤-作物-大气连续体角度出发,依据农田土壤水分平衡理论,利用内蒙古突泉农业气象试验站2001—2007年土壤水分数据和气象资料,建立了适合内蒙古东北部旱作农区的大豆灌溉动态预报模型,实现了灌溉日期和灌溉量的时域滚动预报;利用2008—2011年实测数据验证该模型模拟结果,土壤相对湿度预测值与实测值的均方根误差(RMSE)和平均绝对百分比误差(MAPE)分别为2.44%和3.42%,预报灌溉日期的误差在-3~3 d之间,表明模型准确性和实用性较强,可为东北大豆产区节水灌溉提供一定的科学依据。

An dynamic irrigation prediction model for soybean in northeast of Inner Mongolia

In order to realize the dynamics irrigation prediction for the soybean in northeast of Inner Mongolia, the polynomial fitting method was applied to interpolate the suitable soil moisture lower limit value for each day in whole soybean growth period, to form the dynamic index curve for the suitable soil moisture index lower limit. Started from the point of view of soil-plant-atmosphere continuum, based on the theory of soil water balance, using the soil moisture data and meteorological information from 2001 to 2007 of agricultural meteorological station in Tuquan County of Inner Mongolia, was set up the dynamic irrigation forecasting model for soybean that was suitable to the dry farming area in northeast of Inner Mongolia, to realize the time domain rolling forecast for the irrigation date and irrigating. The model simulated results were verified by the observed data from 2008 to 2011. The root mean square error(RMSE) and the mean absolute percentage error(MAPE) between the predictive and measured values of relative soil moisture were 2.44% and 3.42%, respectively. The error between the forecasting and actual irrigation date was within ±3 days. It indicated that accuracy and practicability of the model were rather strong. The research results can be provided certain scientific basis for developing water saving irrigation in soybean producing area of Northeast China.