中文摘要：

农户水稻种植“双改单”正以一种不可逆转的态势发展。由于农民种稻收入在家庭收入增长中份额日趋减少,使得农户倾向于将更多劳动时间和生产资源转移到兼业或非农生产活动上,出于粮食安全和提高耕地利用率的考虑,国家鼓励农户选择双季稻,而农村社会化服务的推进和发展,能够促进生产者劳动时间和生产资源的有效配置,来兼顾到粮食安全和农民增收的目标。本文在我国长江流域的农户追踪数据基础上,分析农户水稻“双改单”和收入增长的演变趋势,以农村社会化服务为视角,尝试构建一个理论模型并实证分析以回答,在农村社会化服务发展的支持下,能否使得农户兼顾到双季稻种植和收入增长的双重目标？研究结果表明：2004-2010年,农户水稻“双改单”趋势明显,双季稻比例年均降幅达1.82个百分点,2010年双季稻种植比例已降至三成左右。水稻生产者的非农兼业类型正由传统的种养结合经营逐渐向农业以外产业拓展,到2010年生产者的职业所属行业排名前三位分别为工业、建筑业和水面养殖业。以农机装备为代表的农村社会化服务的发展,尚不能使农户兼顾到收入增长与双季稻种植的双重目标,农村社会化服务的主要贡献在水稻生产者的非农兼业行为上,对其选择单双季水稻的影响较小。由于可在务农与非农劳动时间上进行错峰配置,生产者的非农兼业行为与其单双季水稻种植之间具有互补性,然而也有微弱迹象显示,随着生产者非农兼业程度的进一步提高,将可能对单双季水稻种植产生负面影响。文章建议,要切实保障粮食安全目标,应当重视长江流域水稻主产区的农户“双改单”演变趋势,继续拓展水稻产前、产中和产后环节上的农村社会化服务内容.适当培育现代职业农民。引导农民扩大双季稻的种植规模。

英文摘要：

The switch from double-cropped to single-cropped rice is an irreversible trend in rice planting in China. Due to the continuous decrease of rice planting income in household income, farmers tend to allocate more time and resources to non-agricuhure activities. However, the government encourage farmers to plant double-cropped rice based on the importance of strategic grain reserve and the full utilization of arable land. The social services in rural areas can efficiently improve the allocation of labor time and resources, as well as food security and increase household income. The present study investigated the planting pattern switch from double-cropped to single-cropped rice and the income changes based on data from farmers in the Yangtze River Basin, China. The aim of the present study was to establish a theoretical model to understand whether social services in rural areas can encourage farmers to plant double-cropped rice, and increase their income at the same time. A substantial switch from double-cropped to single-cropped rice was observed during 2004 - 2010 in the Yangtze River Basin, China. The proportion of double-cropped rice decreased annually 1.82% during this period and the planting of double-cropped rice accounted for only one third of the total rice planting in 2010. Traditional rice farmers allocated more labors and resources to non-agriculture activities, especially industry, construction, and aquaculture. The social services in rural areas, which is primarily based on agricultural equipment, were not feasible for farmers to increase household income through planting double-cropped flee. In addition, the social services in rural areas had limited influence on the decision of planting double-cropped or single-cropped flee, but mainly contributed to non-agriculture activities of farmers. The labor and time can be reasonably allocated between agriculture and non-agriculture activities, therefore, the non-agriculture activities of rice farmers are compatible with the pattern of double-cropped rice. H