Crop diversity between 20 and 90 percent crop losses in the Congo. The FAO emergency relief and rehabilitation program is assisting vulnerable returnee populations in the African Great Lakes Region through mass propagation and distribution of CMD resistant or highly tolerant cassava. A well known occurrence of disease susceptibility in crops lacking diversity concerns the 'Gros Michel', a seedless banana that saw world marketing in the 1940s. As the market demand became high for this particular cultivar, growers and farmers began to use the Gros Michel banana almost exclusively. Genetically, these bananas are clones, and because of this lack of genetic diversity,
Crop residue above-ground plant in the first year. There is some residual benefit of fertilizers as the crops take up a small amount of the nutrients two and three years later. Fertilizer placement can significantly affect the efficiency of crop uptake. The impact of residue placement (buried by tillage or left on the surface in zero tillage) on nutrient cycling and efficiency is under study. Thus, the practice of calculating the fertilizer equivalent value of the nutrients in crop residue is a reasonable guide to estimating the partial value of crop residues. Crop residue There are two types of agricultural crop residues.