International Journal of Agricultural Policy and Research Vol.3 (11), pp. 402-411, November 2015
Low crop production in most arable lands is associated with soils highly depleted of nutrients. A study was conducted in selected physiographic units of Mbeya Region Tanzania, to investigate the levels of soil macro- and micronutrients effect on crops (rice, wheat and beans) performance. Soils were analyzed in the laboratory. Screen-house experiments with three levels of Zn (0, 7.5 and 15 mg kg-1 soil) and Cu (0, 5 and 10 mg kg-1 soil) in combination with N and P treatment in completely randomized design with three replications was conducted. The results showed that all soils were deficient in N, P and Cu, while 46% of soils had low Ca. Zn was low in 46% of the soils while K and Fe was sufficient in all soils. Application of 15 mg kg-1 Zn and 5 mg kg-1 Cu with N and P fertilizers gave significantly highest grain yield of rice (9.05 g pot-1), beans (5.80 g pot-1) and wheat (5.58 g pot-1). The control gave lowest grain yield in all crops. Zink rate of 15 mg kg-1 and Cu rate of 5 mg kg-1 was sufficient to increase yields in these soils. Field experiments are recommended to confirm Zn and Cu fertilizer recommendations.