湿润灌溉条件下水稻田土壤水分时空分布及预测模型研究

Study on Time-Space Distribution and Prediction Models of Soil Moisture in Paddy Fields under the Wetting Irrigation

摘要: 以实地观测为基础，在湿润灌溉条件下分析研究了拔节孕穗期、抽穗开花期及乳熟期等三个主要需水阶段水稻田土壤水分空间分布及影响因素，并建立了土壤水分预测模型。结果表明，在作物有效根系层0~40 cm内，中稻稻田土壤水分时空分布存在显著差别。相关分析及显著性检验结果显示，土壤含水率对田间气温及地下水埋深响应较为敏感，对相对湿度及风速响应次之，对气压响应最弱。回归及误差分析结果也表明，对主要气象因子及地下水埋深等回归建立的多元线性模型，最大测量误差分别为2.92%、4.73%和4.85%，拟合效果满意。研究成果为湿润灌溉条件下水稻田土壤水分预测奠定了基础，也为节水灌溉制度的科学制定提供了理论依据。

Abstract: Based on field test, the article analyzed the time-space distribution and influence factors of paddy soil moisture at three main growth stages (including jointing booting, heading to flowering, milk stage), and prediction models of soil water were established. The results showed that temporal and spatial distribution of soil moisture in semilate rice paddy was significantly different in 0~40 cm root zone. The results suggested the response of soil moisture content to temperature in the field and water table were sensitive, to relative humidity and wind took second place, and to atmospheric pressure was the worst. Multi-regression analysis and error analysis also showed that the multi-linear regression models of soil water established based on major meteorological factors and water table at the three different growth stages were satisfying, and the maximum relative errors are 2.92%, 4.73% and 4.85% respectively. The research can lay a foundation for forecasting of paddy soil water under the wetting irrigation, and supply a theory basis for water-saving irrigation program.