中文摘要：

水早轮作系统是我国主要的作物生产系统之一，主要分布在长江流域．作物和土壤季节间的干湿交替变化是这一系统的显著特征，这也引起了土壤物理、化学和生物学特性在不同作物季节间的交替变化，构成独特的农田生态系统．该系统面临的主要问题包括：生产力下降或徘徊不前，灌溉水日益短缺，养分管理不合理，资源利用效率低和环境污染等．本文在综述水早轮作系统特征和存在问题的基础上，进一步提出通过养分资源综合管理策略解决该系统养分投入、作物生产和环境风险之间的矛盾．该策略的核心内容是：从整个轮作系统角度出发调控养分，综合应用各种养分资源（化肥、有机肥及环境养分），使养分供应匹配作物需求，并根据不同养分资源特点采取相应的管理技术，使养分管理与节水、高产栽培等农作技术相结合。

英文摘要：

Paddy rice-upland crop rotation system is a major cropping system in China, and practiced widely along the Yangtze River basin. A unique feature of this system is the annual conversion of soil from aerobic to anaerobic and then back to aerobic condition, which can result in the changes of soil physical, chemical, and biological prosperities among seasons, making a special agroecosystem. The major challenges faced by this system include declining or stagnating productivity, increasing shortage of irrigation water, improper management of nutrients, low efficiency of resource utilization, and environmental pollution. Based on an overview of the characteristics and problems of paddy rice-upland crop rotation system, this paper put forward a strategy of practicing integrated nutrient management to solve the contradictions between nutrient input, crop production and environmental risk. The key points of this strategy included nutrient management from the whole rotation system perspective, integrated use of nutrients from various sources （chemical fertilizers, organic. fertilizers, and nutrients from the environment）, synchronization of nutrient supply and crop nutrient demand, application of different management technologies based on the characteristics of different nutrient resources, and integration of nutrient management with other cropping system technologies like water saving and high-yielding cultivation, etc.