江汉平原中稻蓄雨灌溉实证研究

Empirical Study on Rain Storage Irrigation for Mid-Season Rice in Jianghan Plain

摘要: 中稻是江汉平原广泛栽培的粮食作物，根据水稻不同生长阶段对淹水的适应性和适当蓄雨，对节约灌溉用水、减少田间排水以及养分流失具有重要意义。以水稻浅水勤灌为对照，并基于浅水勤灌设置3种蓄雨上限(100 mm、80 mm、60 mm)，在自然降水条件下开展水稻蓄雨灌溉测坑试验。2年试验结果表明：与对照相比，蓄雨灌溉在节约灌溉用水、减少田间排水方面具有明显优势，同时，由于水稻本田期降水2年不同，蓄雨灌溉的效果也不相同。2018年水稻本田期降雨为371.5 mm，蓄雨灌溉与对照相比，节约灌溉用水13.72%~15.30%，减少排水55.44%~60.64%，蓄雨提高12.62%~13.81%；2019年水稻本田期降雨(187.1 mm)仅为2018年同期的50.36%，蓄雨灌溉效果不如2018年，与对照相比，节约灌溉水5.55%~8.26%，减少排水69%左右，蓄雨提高16%左右。蓄雨100、80、60 mm，3种灌溉模式在利用天然降雨减少田间灌溉水量和径流排水量的同时，水稻主要农艺性状和产量并无显著差异，说明适当的蓄雨灌溉不会引起水稻减产。同一年内不同蓄雨灌溉的灌溉水生产率很接近，可能的原因是当年水稻本田期降水不多、不同蓄雨上限的蓄水差异未得到充分体现。

Abstract: Medium rice is a widely cultivated grain crop in Jianghan Plain, according to the adaptability of rice in different growth stages to flooding and appropriate rain storage, it is of great significance to save irrigation water, reduce field drainage and nutrient loss. Three rain storage limits (100 mm, 80 mm and 60 mm) were set based on shallow-water frequent irrigation that was taken as control, and the pit test of rain storage irrigation for rice was carried out under natural precipitation. The results of the 2-year (in 2018 and 2019) experiment show that compared with the control, rainwater storage irrigation has obvious advantages in saving irrigation water and reducing field drainage, while the effect of rain storage irrigation is not the same because the precipitation in field growth period of rice is different in the two years. Compared with the control, rainwater storage irrigation in 2018 which the rainfall in filed growth period of rice was 371.5 mm could save irrigation water by 13.72% to 15.30%, reduce drainage by 55.44% to 60.64%, and increase rainwater retained in the field by 12.62% to 13.81%; the rainfall (187.1 mm) in field growth period of rice in 2019 was only 50.36% of that in the same period of 2018, and the rain storage irrigation effect was not as good as that in 2018, compared with the control, irrigation water was saved by 5.55%~8.26%, drainage was reduced by 69%, and rainwater retained in the field was increased by 16%. There were no significant differences in the main agronomic traits and yield of rice under the three irrigation modes of 100, 80 and 60 mm rain storage, indicating that appropriate rain storage irrigation could not reduce the yield of rice. In the same year, the irrigation water productivity of different rain storage irrigation is very close, the possible reason is that the precipitation of rice Honda period in the same year is not much, and the difference of water storage of different rain storage ceilings is not fully reflected.