基于ORYZA＿V3模型的水稻节水灌溉模式研究——以赣抚平原灌区为例

Research on Water-saving Irrigation Modes Based on ORYZA＿V3——A Case Study of the Ganfu Plain Irrigated Area

作物生长模拟能克服田间试验的不足,为水稻种植的节水增产提供参照。基于江西省灌溉试验中心站2012、2013年的田间试验资料对ORYZA_V3模型进行率定及验证。使用率定后的模型模拟1961-2016气象条件不同灌溉模式下试验区的早晚稻生长,分析丰、平、枯水文年组早晚稻产量、灌溉定额、灌水次数、腾发量、降雨利用率、水分生产率的差异。结果表明:在一定范围内降低灌前水分下限能提高试验区早晚稻的产量。当灌前水分下限降低到一定水平后增产率将有所下降。降低灌前水分下限,能降低灌溉定额、灌水次数及腾发量,提高降雨利用率,提高水分生产率。从节水增产的角度,推荐试验区早稻在丰、平水年采用重度干旱的节水灌溉模式W4(耕作层灌前土壤含水率下限占饱和含水率65%),枯水年采用中度干旱的节水灌溉模式W3(耕作层灌前土壤含水率下限占饱和含水率75%)。与传统淹灌模式W0相比在丰、平、枯水年能分别增产2.1%、2.6%、1.6%,节水38.4%、48.8%、47.4%。推荐试验区晚稻在丰、平水年采用中度干旱的节水灌溉模式W3,枯水年采用轻度干旱的节水灌溉模式W2(耕作层灌前土壤含水率下限占饱和含水率85%)。与传统淹灌模式W0相比在丰、平、枯水年能分别增产2.7%、3.2%、1.9%,节水37.6%、27.9%、15.7%。

Crop growth simulation can overcome the deficiencies in field experiments and provide references for water-saving and yield increase in rice cultivation. In this paper,ORYZA_V3 model is calibrated and validated based on the field experiment data of the Jiangxi Provincial Irrigation Experiment Central Station. The model is used to simulate the growth of early and late season rice in the experimental area under different irrigation modes during the period of 1961-2016. Then, the yield, irrigation quota, number of irrigation,evapotranspiration,rainfall utilization rate and water productivity of the early and late season rice in dry,normal and wet years are analyzed.Acoording to the results: reducing the lower limit of moisture before irrigation in a certain range can increase the yield,the rainfall utilization rate and the water productivity of early and late season rice,which can also reduce the irrigation quotas and irrigation times. When the lower limit of moisture before irrigation decline to certain level,the yield increasing rate of early and late rice will decrease. From the perspective of increasing water production,severe drought water-saving irrigation mode( the lower limit of soil moisture content before tillage irrigation accounts for 65% of saturated water content) is recommended for planting early season rice in wet or normal years,and milddle drought water-saving irrigation mode( the lower limit of soil moisture content before tillage irrigation accounts for 75% of saturated water content) is recommended for planting early season rice in dry years which can increases yeilds by 2.1%,2.6%,1.6%,save water by 38.4%,48.8%,47.4% in the wet years,normal years and dry years. Middle drought water-saving irrigation mode is recommended for planting late season rice in wet or normal years,and mild drought water-saving irrigation mode( the lower limit of soil moisture content before tillage irrigation accounts for 85% of saturated water content) is recommended for planting late season rice in dry years which can increase yeilds by 2.7%,3.2%,1.9%,and save water by 37.6%,27.9%,15.7% in the wet years,normal years and dry years.