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该文依据2001~2004年4年田间试验资料,利用Penm an-M on te ith公式计算了北京地区旱稻出苗~成熟期间参考作物蒸散量,并利用农田水量平衡方程及土壤水分胁迫系数计算了作物实际蒸发蒸腾量,由此计算了旱稻各生育阶段的作物系数,并分析了旱稻作物系数变化规律。结果表明:北京地区旱稻出苗~成熟期间参考作物蒸散量平均为560.1 mm;日平均孕穗~开花期最高为6.8 mm/d,年际变化幅度很小。旱稻作物系数全生育期平均为1.07,在孕穗~开花期最大,为1.49,其次为开花~成熟阶段,平均为1.20,拔节~孕穗最小为0.87;在北京气候背景下,旱稻作物系数与出苗后天数和大于0℃积温具有较好的三次多项式关系。
Based on the field experiment data of four years from 2001 to 2004, the reference crop evapotranspiration was calculated using the Penm an-M on teith formula during the emergence and maturity of Upland rice in Beijing. The crop yield was calculated using the field water balance equation and soil water stress coefficient The actual evapotranspiration was calculated, and the crop coefficient of each stage of upland rice was calculated, and the variation rule of the crop coefficient of upland rice was analyzed. The results showed that the average amount of reference evapotranspiration during the emergence and maturity of upland rice in Beijing was 560.1 mm, the highest average booting and flowering stage was 6.8 mm / d, and the interannual variability was small. The average growth coefficient of Upland rice was 1.07 in the whole growth period, 1.49 in booting ~ flowering stage, followed by flowering ~ maturity stage, with an average of 1.20, and the minimum in jointing ~ booting was 0.87. Under the Beijing climate background, Number and greater than 0 ℃ accumulated temperature has better cubic polynomial relationship.