G. Soropa, G.A. Mavima, T. P.
A study was conducted to determine phosphorus (P) release potential of pelletized phosphate blends (PPB) enhanced cattle manure using incubation for two soils in Zimbabwe. The rate of P mineralization for untreated and PPB treated manures was determined using the Bray 1 method on destructive samples (2 g sub-sample) of the soils collected 3, 7, 14, 28 and 42 days after incubation had commenced. The results of the incubation study showed a significant decrease in the amount of P release into solution for the two soils. Results obtained showed net immobilization for both the PPB treated manures and untreated cattle manure for both Buhera and Marenga soils. This means that both untreated manure and PPB enhanced cattle manures have low agronomic potential to effectively restore P status of the P deficient soils for sound crop production. The study confirmed that if rock phosphate is mixed with cattle manure without composting, there is no improvement in P availability and uptake by maize.