The Productivity of Orange Fleshed Sweet Potato as Influenced by Organic Manure and Inorganic Amendments in Dodoma Municipal

Abstract

A new variety of orange-fleshed sweet potato (Carrot-C) has been introduced in Dodoma Municipal but appropriate soil nutrient management for this cultivar is lacking and the yield is below its potential. Smallholder farmers are not aware of when Farm Yard Manures and inorganic fertilizers are incorporated together into the production of this crop. The present study identified the best combination of farm yard manure at four levels (0 tha^-1, 5 tha^-1, 10 tha^-1, and 15 tha^-1) and phosphorus at four levels (0 t of P₂O₅ha^-1, 23 t of P₂O₅ha^-1, 46 t of P₂O₅ha^-1, and 69 t of P₂O₅ha^-1) for orange-fleshed sweet potato production. In the on-farm experimentation, a factorial arrangement was used. The Randomized Complete Block Design was adopted with three replications. Partial budgeting and marginal analysis involving dominance analyses were used as analytical tools. The results of Partial budgeting analysis at 15t Farm Yard Manure/ha in a combination of 69t of P₂O₅/ha gave a positive and greatest net benefit of 25,814.5 TZS/ha and its Marginal Rate of Return was highest at 6,666.5%. In conclusion, the use of 15t Farm Yard Manure/ha plus 69t of P₂O₅/ha is viable and is recommended for farmers to use in their plots to earn the highest income.