基于作物需水与自然降水适配度的湖南省防旱避灾种植制度优化

季节性干旱对湖南省农业生产造成很大影响,明确防旱避灾种植制度,可为指导当地农业生产提供科学依据。基于湖南省代表站点1981-2007年的气候数据和作物生育期资料,依据干燥度和地形地势特点,划分不同类型区,并在各区域内选取代表站点和代表性种植制度,采用FAO推荐的分段单值平均作物系数法订正了作物系数。比较了主要种植制度的作物需水与自然降水适配度及作物需水与自然降水适配度保证指数,确定了湖南省基于自然降水的防旱避灾种植制度。研究结果表明:各区域基于自然降水资源的防旱避灾种植制度分别为:(1)湘中偏北湿润中低海拔地形复杂区和湘东北半湿润中低海拔山地丘陵区为麦-稻和薯-稻种植模式;(2)湘北半湿润低海拔平原区为油-棉、油-稻和豆-稻种植模式;(3)湘东偏北半干旱低海拔平原与盆地丘陵过渡区为油-苕、油-棉和油-稻种植模式;(4)湘东南较干旱中低海拔丘陵区为油-稻、麦-稻和薯-稻种植模式;(5)中南部较干旱中低海拔盆地区为油-稻和油-棉种植模式;(6)湘西北较湿润中高海拔中山低山区为薯-稻和油-苕种植模式;(7)湘西南较湿润中高海拔丘陵区为油-苕、油-稻、麦-稻和薯-稻种植模式;(8)湘西干旱高海拔山地丘陵区为油-苕和油-棉种植模式。

Optimized cropping systems to prevent and avoid the drought disaster based on the adaptation between precipitation and crop water requirement in Hunan Province

Seasonal drought has serious affections on agricultural production in Hunan Province, Developing an optimal cropping system to prevent and avoid drought disaster could provide scientific guidance for local agriculture production. In this study, adaptation and ensure index between precipitation and crop water requirement were analyzed using weather and crop phenological data of representative stations in Hunan Province from 1981 to 2007. Then optimal cropping systems based on precipitation were evaluated for the local agriculture to prevent and avoid local seasonal drought. Representative stations and cropping systems were selected according to the aridity and topography. And crop coefficients used in the study were amended using the time-averaged single-value approach recommended by FAO. Results showed that: (1) the optimal cropping systems were wheat-rice and potato-rice in humid low-altitude complex-terrain area of north Hunan Province and sub-humid medium-low altitude hilly area of northeast Hunan Province,(2) while in sub-humid low-altitude plains area of north Hunan Province, it was more suitable to adopt cropping systems of rape-cotton rape-rice and soybean-rice, (3) in sub-arid low-altitude plains and hilly transitional area of east Hunan Province, optimized cropping systems were rape-sweet potato, rape-cotton and rape-rice Similarly, for the other areas, it was,(4) rape-rice, wheat-rice and potato-rice in arid low-altitude hilly area of southeast Hunan Province, (5) rape-rice and rape-cotton in arid low-altitude basin area of middle-south Hunan Province, (6) potato-rice and rape-sweet potato in the humid high-altitude hilly area of northwest Hunan Province, (7) rape-sweet potato, rape-rice, wheat-rice and potato-rice in humid high-altitude hilly area of southwest Hunan Province, (8) and rape-sweet potato and rape-cotton in arid high-altitude hilly area of west Hunan Province.