风沙区春小麦作物系数试验研究

Crop Coefficients of Spring Wheat in Windy Dust Area

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

Crop coefficient is one of the most important parameters needed for crop water requirements using the reference crop method. In this paper, crop coefficients of spring wheat (k c) were calculated by using the water balance method. The change of k c during spring wheat growing period in windy dust area was analyzed. The k c as functions of days after planting (DAP) and cumulative growing degree (CGD) were derived, and the third k c was derived from the data using the FAO 'Straight-Line' Method. The results showed that there were good sixth-order polynomial and forth-order polynomial relations between k c and DAP and CGD, respectively. The high coefficients of determination (R 2>0.94) for the DAP and CGD regressions indicate that the curves fit the data well. The three typical k c values, derived by using the FAO 'Straight-Line' Method at the initial, middle growth stages and at harvest data were 0.57, 1.70, 0.55, respectively.