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作物系数是利用参考作物法计算作物需水量的重要参数之一。该文利用水量平衡法反求春小麦的作物系数 ,分析了风沙区春小麦作物系数在生育期内的变化规律 ,建立了春小麦作物系数与播后天数、生育期累积积温关系的函数曲线 ,同时还采用 FAO分阶段直线法构建了春小麦作物系数曲线。结果表明 ,春小麦作物系数与播后天数和生育期累积积温之间分别呈现出良好的 6次多项式关系和 4次多项式关系 ,回归曲线与数据点拟合得非常好 ,相关系数 (R2 )均在 0 .94以上 ;采用 FAO分阶段直线法得到的 3个典型值分别为 :初始生长期 0 .5 7、生育中期 1.70、收获时 0 .5 5
The crop coefficient is one of the important parameters for calculating the crop water requirement using the reference crop method. In this paper, the water balance method was used to reverse the crop coefficient of spring wheat. The variation of spring wheat crop coefficient during the growth period was analyzed. The function curve of the relationship between crop coefficient and days after sowing and accumulative accumulated temperature during growing period was established. FAO staged straight line method of spring wheat crop coefficient curve. The results showed that there was a good sixth-order polynomial relationship and a fourth-order polynomial relationship between crop coefficient and days after sowing and accumulated accumulated temperature during spring wheat. The regression curves fitted well with the data points. The correlation coefficients (R2) 0 .94 or above. The three typical values obtained by adopting the staged straight-line method of FAO are as follows: the initial growth period is 0.57, the middle growth period is 1.70, and the harvesting time is 0.55