中国低产田状况及改良策略

THE STATUS AND RECLAMATION STRATEGY OF LOW-YIELD FIELDS IN CHINA

从新阶段我国农业、特别是土壤学发展的需求出发,总结了国内外有关低产田方面的研究成果。从"低产田"的界定入手,对我国低产田的状况及其负面影响、低产田形成的自然要素和人类活动的影响以及主要障碍因子等进行了系统分析,并初步测算了低产田改良的粮食增产潜力等。我们认为"低产田"可以定义为"在现有的正常耕作栽培管理技术水平条件下,因为耕地本身存在的障碍或者限制因子,导致作物生长发育差,产量较当地高产田低30%以上,且年际间变异大的农田"。我国低产田具有面积大、类型多,而且分布相对集中、障碍因子较明显等特征,低产田主要的障碍因子包括:有机质贫乏、养分匮乏或失衡、土壤酸化、土壤盐渍(碱)化、沙化、土壤板结、潜育化、表土大量流失、严重干旱、多因子组合。在此基础上,最后从我国现代农业发展的迫切需求出发,提出了今后一段时间内低产田改良研究的重点及有关政策和对策建议。

In the light of the development of agricultural research, especially soil science, at the current stage of China＇ s development, the related research achievements on low-yield fields at home and abroad are summarized. The def- inition, status, negative effects, causes and main limitations of low-yield fields are systematically analyzed. The increasing grain production potential is preliminarily estimated from the improvement of low-yield fields. The ＂low-yield fields＂ can be defined as those in which existing limitations cause poor crop growth and thus have 30% lower yields than fields with local high-yields. They have large annual variations in yield under normal tillage cultivation management. The low-yield fields in China are characterized by having large areas, more types of low-yield fields, a relatively concentrated distribution and more apparent yield limitations. The main limitations in low-yield fields include low organic matter and low and unbalanced nutrient concentrations, soil acidification, soil salinization, desertification, soil hardening, soil gleyization, erosion, and severe drought. Finally, further research topics and suggestions, based upon different policies and strategies to support the reclamation of low-yield fields, are proposed.