Comparative Effects of MPR and P Water Soluble Fertilisers on Maize Yield in Sandy Soils of Tabora, Tanzania

An on-station experiment was conducted at ARI –Tumbi, Tabora, Tanzania during 2010/ 2011 cropping season to compare the effects of Minjingu Phosphate Rock (MPR) with various water soluble P fertilisers on maize response in sandy soils. Water soluble fertilisers used in the experiment were Diammonium phosphate (DAP) at 30 and 15 kg P /ha, and NPK 10-18-24 at 30 kg P /ha. Water insoluble MPR in powder and granule forms was applied at 30 kg P /ha. The experiment layout was a Complete Randomized Block Design (RCBD), with a P control treatment applied with 100 kg N/ha, which was the same rate applied to all P treated treatments. The maize mean yields were 2836, 3688, 3839, 3988, 4014, 4612 (kg/ ha) for control, DAP 15, DAP 30KG, MPR granules, MPR powder, and NPK treatments, respectively. Control treatment had the lowest yield which was significantly different (p= 0.005) with the P treated treatments. There were no significant differences in maize mean yields when MPR treatments were compared with DAP and NPK treatments at 30 P kg/ ha. This implies that the fertilization of maize with MPR can replace the NPK and DAP fertilisers provided that N and other necessary nutrients are applied. Maize mean yields in MPR powder treatment was relatively higher to MPR granules treatment, but the difference was not significant (p= 0.05) implying that both granules and powder forms can be recommended to be used by farmers, but farmers applying powder form can increase their yields. The highest yield attained in NPK treatment might be contributed by the presence of K in fertiliser because soil analysis showed the nutrient level was low.