关键词: 夏玉米, 沙壤土, 沟灌, 畦灌, 水分生产率

Abstract: For saving water and increasing yields an experimental study on furrow irrigation, border irrigation and reducing irrigation times during summer corn's growing period was conducted in the sandy loam region with poor preservation of soil moisture in North Henan. Irrigation water quota under border irrigation was 630~682.5 m³·hm^-2, while that under furrow irrigation only averaged 442.5 m³·hm^-2. The results show that the growing rate of plant's height and leaf area ind ex of summer corn increase rapidly before the tasselling stage, plant of height reaches about 2.5 m at tasselling time, then the growing rate slows down obviously. The leaf area index remains at the highest value of 5.40~5.92 from the tasselling stage to the initial stage of grain filling, then decreases sharply. Under different irrigation treatments, the plant's height and leaf area index increase with the total application of water. In dry years, water consumption of summer corn in whole growth period under border irrigation was 4 278 m³·hm^-2, that under furrow irrigation and i rrigation treatments with water amount reduced was 3 762 m³·hm^-2 a nd 3 348 m³·hm^-2 respectively. Daily water consumption from the tasselling stage to flowering stage was the biggest, it was 66.75~76.50 m³·hm^-2; from jointing stage to tasselling stage that was 65.50 m³·hm^-2 and fr om sowing to seedling that was only 13.35 m³·hm^-2. Grain weight per e ar, 1 000 grain weight and the ratio of grain weight to ear weight were affected by various irrigation methods and water amount of irrigation. Compared with border irrigation, furrow irrigation which was used for crops sparsely sown in wide rows, has more advantages stat ed as follows:① water use for irrigation being less (442.5 m²·hm^-2 in average), ② irrigation water collecting around the root system of plants and i ntrarow evaporation being low, ③ grain weight per ear and 1 000 grain weight being high and yield reaching 9 616.5 kg·hm^-2, and ④ it saving irrigation water by 22.8% and raising water productivity by 16.9%. During the growing period of summer corn, a reduced number of irrigation times easily results in a gr eat loss of yield (13.7%). Therefore, precaution must be taken to prevent water stress caused by water shortage in dry years.

Key words: Summer corn, Sandy loam, Furrow irrigation, Border irrigation, Water productivity