Abstract:
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.
