不同水分处理旱稻农田蒸散特征和水分利用效率

Field evapotranspiration characteristics and water use efficiency of aerobic rice under different water treatments

该文通过2001～2004年4年北京地区旱稻田间试验,利用农田水量平衡方法计算了旱稻农田蒸散量,用微型棵间蒸渗仪测定了不同土壤水分条件下农田土壤棵间蒸发,在此基础上分析了不同水分处理旱稻生长期间的农田蒸散特征、土壤棵间蒸发特征和水分利用效率。结果表明:北京地区旱稻出苗～成熟的农田蒸散量为574～630mm,年际间略有波动;日蒸散强度孕穗～抽穗期最高,平均为9.8mm/d,该阶段为旱稻需水关键期;在出苗～拔节期间土壤棵间蒸发量占农田蒸散量比例最大,在此生育阶段应采取适当措施降低土壤蒸发无效消耗,提高水分利用效率;限量灌溉处理中以前期适当胁迫,后期充分灌溉处理的水分利用效率最高。

Four years＇ experiments （2001-2004） were conducted in Beijing from 2001 to 2004 to study the characteristics of crop evapotranspiration （ET）, soil evaporation, and water use efficiency （WUE） of aerobic rice under four different water conditions. Crop evapotranspiration was calculated from the soil water balance equation, and soil evaporation was measured by micro-lysimeter in the field. Results showed that the total ET during the whole growing season of aerobic rice in Beijing varied between 574 and 630 mm among years. The highest daily ET occurred at the stage from booting to heading stage with the average value of 9.8 mm/d. Therefore, booting to heading is the key stage of water requirement for aerobic rice. More than 40% of the total ET was consumed during the period from emergence to jointing, however, most of this part of ET was used for soil evaporation. Therefore, it is necessary for efficient water use to take some measures to reduce the consumption of soil evaporation at this stage. Comparing among water treatments, WUE was the highest in the treatment with limited irrigation before jointing but sufficient irrigation thereafter.