Simulating Sorghum Yield Response To Mineral Fertilizer In Semi-Arid Northern Ghana

2008

English

In the past, farmers used long fallow periods to restore soil fertility of their fields. This practice has now given way to continuous cropping of the same fields thereby leading to low crop yields. There is therefore a need to evaluate various options of improving soil fertility and crop productivity. In our work, the Decision Support System for Agrotechnology Transfer (DSSAT) was used to assess the yield response of sorghum to varying levels of mineral fertilizers in Navrongo, northern Ghana. DSSAT predicted well the effects of the varying levels of mineral fertilizers on total biomass and crop yields, with an internal efficiency of the model (E1) of 0.63 and 0.69, respectively. Application of 40 kg N/ha in the homestead yielded the best value-to-cost ratio, whereas 80 kg N/ha1 produced the highest value to cost ratio in the bush farms. Yield projection into 2035 showed that the amount and distribution of rainfall poses a higher risk to efficient use of mineral fertilizer on soils with low organic matter (bush farm) content than to soil with higher (homestead) content of organic matter. Also, food security can only be assured by using inorganic fertilizer and organic matter

Kpongor, D. S.; Tabo, R.; Bationo, A.; Fosu, M.; Vlek, P.