A discussion on land fallow rotation problems in ecologically fragile areas of the southwest karst area: A case study of Guizhou Province

The implementation of land rotation fallow has been an effective way of realizing the supply side reform of agriculture and specifically for the realization of the implementation of food crop production strategy based on farmland management and technological application. This has had a strategic impact on the development of green agriculture and guaranteeing national food security. The ecologically fragile area of the southwest karst is one of the key pilot areas of land rotation fallow system and Guizhou Province is a typical karst region. It is therefore important to analyze current conditions and develop countermeasures of land rotation fallow systems in Guizhou Province. This will give a better idea on land rotation fallow in the study area. This paper analyzed the necessity of land rotation fallow systems from two aspects-cultivated land quality and environment of Guizhou. On the basis of current conditions, the problems of land rotation fallow systems in Guizhou were put forward. Among them, the most prominent problem was the current crop rotation system in Guizhou was small without unique characteristics, and mostly passive and inappropriate. On the basis of the existing problems, countermeasures were suggested, and the implementation of land rotation fallow system, technical paths of land rotation fallow systems in different degraded/cultivated lands were discussed in detail. Highly fertile land was more suitable for developing mountain characteristic farming system, while heavy metal contaminated land should be fallowed continuously. And for areas with continuous cropping obstacle, non-point source pollution or rocky desertification, the measures of reasonable crop rotation and fallow combined with straw return, green manure use, organic fertilization, conservation tillage were suggested. Finally, the practice of land rotation fallow system in Guizhou was evaluated.