To Uplift the Profitability of Marginal Lands by Cassava Cultivation

Expanding the utilization of marginal land resources in rural areas is regarded as a significant supplement for the sustainable development of modern agriculture for its yield, economic and ecological good. Marginal areas, due to their natural limitations, are only productive for energy crops with strong resistance and tolerance. Cassava, in its longstanding cultivation practices, has marked its adaptability in tropical and subtropical regions. Farmers are allowed to improve reclaimed soils’ fertility, while plants’ canopy coverage could reduce soil erosion. Besides, cassava tubers to be produced as food or fodder can be counted as soil productivity. Breeding advanced cassava varieties on marginal land under proper intensification management and facilitating policies can indeed increase farmers’ income. Some of the projects implemented outside of China speak quite well on that. Additionally, intercropping modes for cassava bring higher incomes than monocropping mode, which simultaneously improves the ecosystem structure and soil conditions. The interspecific cooperation brought by the intercropping pattern has its buffering function and antagonistic effects to counter against plant diseases, pest attacks and weed infestations. It performs as a natural alternative for pesticides and fertilizers with minimal inputs and safe and productive outputs. Although a complete cassava industrial chain has been formed nationwide, there are still challenges like the inadequate use of marginal areas and risks triggered by unfavorable climate, changeable commodity markets, and the composition of the labor force. However, there will still be ample room for further growth of cassava, for recent years have witnessed the acceleration in the circulation of rural land management rights and the stratification of Chinese farmers, which gives an impetus to household management’s dominance as well as the improvements of rural social welfare systems for the overall agricultural efficiency.

Core Collection of Cassava ( Manihot esculenta Crantz) Germplasm

[Objective] This paper aimed to construct the core collection of cassava germplasm. [Methods] Parameter values of six traits of 161 clones were ana-lyzed and evaluated. [ Results] Minkowski genetic distance was established for cluster analysis of core collection. Preferred sampling method （D 2C5S3） was suit-able for the construction of the core collection of cassava. A total of 25 core collections were obtained, which accounted for 15% of the original germplasm and could represent the genetic diversity and integrity of the original germplasms. Meanwhile, it reflected that the genetic background of the tested cassava germplasm was nar-row and the range of genetic diversity was quite small with genetic redundancy. [ Conclusions] Constructing core collection provided a theoretical foundation for the protection and utilization of cassava germplasms.