淮河流域蚌埠闸以上地区夏玉米生育阶段水分供需时空变化特征研究

作物水分供需量是进行科学合理灌溉的重要参考依据,水分供需不平衡也是引起农业旱涝的根本原因。基于淮河流域蚌埠闸以上地区及周边1961—2015年共91个气象站点的日尺度气象数据,借助有效利用系数法计算夏玉米有效降水量,采用联合国粮食及农业组织（FAO）建议的Penman-Monteith（P-M）公式和作物系数法计算需水量,分析夏玉米水分供需时空变化特征,并探讨典型站点夏玉米生育期内水分盈亏状况。结果表明：① 近55a来,研究区夏玉米全生育期和各生育阶段有效降水量呈南高北低的分布特征,各站点趋势变化不明显;② 夏玉米全生育期和各生育阶段需水量大致呈南低北高的纬向分布,全生育期和各生育阶段呈显著减少趋势,只少数站点未通过显著性检验;③ 夏玉米全生育期和各生育阶段缺水量大致呈纬向分布特征,全生育期和播种-出苗期呈显著减少趋势,其余生育阶段趋势变化不明显。

Spatial and temporal variations of water supply and demand during the growth stage of summer maize above the Bengbu Sluice in the Huaihe River Basin,China

Crop water supply and demand is an important reference for rational and scientific irrigation. The imbalance of water supply and demand is also the root cause of agricultural drought and flood. Based on meteorological data from 91 stations from 1961-2015 above the Bengbu Sluice in the Huaihe River Basin, we calculated effective precipitation of summer maize by “effective utilization coefficient method”. The water demand was calculated by the Penman-Monteith (P-M) formula and “crop coefficient method” recommended by the FAO. The spatial and temporal characteristics of water supply and demand of summer maize were analyzed, and the change of water budget index during summer maize growth periods was discussed. The water deficit status (including effective precipitation, water demand, water shortage and water deficit index) during the growth period of summer maize at typical stations were also discussed. The results showed that the effective precipitation in the summer maize was higher in the southern region and lower in the northern region in the past 55 years, and the change trend of each site was not obvious. The spatial distribution of water requirement presented a pattern of “lower in the southern region and higher in the northern region”, and the whole growth period and the growth stage in summer maize at most sites showed a significant decreasing trend. The spatial distribution of water deficit presented a pattern of was “lower in the southern region and higher in the northern region”, and most sites showed a significant decreasing trend in the whole growth period and sowing-seeding period. The trend of the other growth stages was not obvious. Comparison of the five typical stations showed the following findings. The water deficit degree of summer maize in northern Zhengzhou station was the most serious. The water deficit amount was about 369 mm in the whole growth period, and the water deficit index was about -0.61. The water deficit degree of Jinzhai station in the south was the lightest. The water deficit amount was about 159 mm in the whole growth period, and the water profit and loss index is about -0.29. Comparison of the water deficit status of summer maize at different growth stages can draw the following conclusions. The water deficit was more serious in the middle and late growth stages than in the early stage. During the tasseling-maturity period, the water shortages at the five stations were 120 mm, 63 mm, 116 mm, 81 mm and 123 mm, respectively, and the water profit and loss indices were -0.60, -0.33, -0.58, -0.42 and -0.59, respectively.