江南红壤丘陵区农业气候特点与作物生产的气候相宜性

The agricultural climatic characteristics and the climaticsuitability for crop production in the red soil hillregion in the south of MidLower Reachesof the Yangtse River Basin

江南红壤丘陵区地处长江中下游南部的中亚热带季风气候区，农业气候的基本特点有①水热资源总量丰富，光资源总量偏低；②降水的季节分配不均匀，春季和初夏雨涝，伏秋干旱，水热同季不同步，光温降水不协调；③光温降水的年际变率大，气候灾害多，农业生产波动性大。春季和初夏持续过量的阴雨洪涝对春播作物的立苗和生长不利，亦是导致该区冬季农业薄弱的主要障碍。伏秋干旱严重胁迫旱地作物的生长。抗逆避灾是作物高产稳产的重要前提。

The red soil hill region,with subtropical monsoon climate,is located in the south of MidLower Reaches of the Yangtse River Basin.Its agricultural climatic characteristics are:1)rich with thermal and water but less with light resources in terms of annual total amount;2)uneven seasonal distribution of precipitation,excessive rainfall in spring and early summer,drought from midsummer to autumn,and the light and temperature do not coordinate with rain in those seasons;3)large variation in light,temperature and rainfall distribution from year to year,high frequency of climatic calamities,and large fluctuation of agricultural production.The excessive rainfall and less sunshine in spring and early summer are not only unfavorable for the emergence and growth of spring sowing crops,but also the main restrict for winter agricultural production in this region.The drought from midsummer to autumn results in severe water stress of nonirrigated farmland crops.The important premise for high and stable yield of crops in this region is to avoid the effects of unfavorable climate.