Assessment of maize response to Minjingu phosphate rock and triple superphosphate applied under different P-application strategies in a Ferralsol in Tanzania

Phosphorus undergoes many reactions in acid soils, most of which convert it to less-available forms. There is a need to search for P source and P-application strategies that minimize the unfavourable reactions and optimize the benefits derived from P application. A field experiment was conducted in a Ferralsol for three years (2004–2006) to compare the effectiveness of Minjingu phosphate rock (MPR) with triple superphosphate (TSP) as assessed by maize response. The same experiment compared two P application strategies, i.e. P recapitalization and seasonal P application strategy, and two P rates, namely a standard P rate (SPR) and half of the SPR. The experiment followed a randomized complete block design with nine treatments replicated four times. Both P sources increased yields, nutrient P and Ca uptake significantly (p < 0.05) over the control, but the difference between sources was not significant. Both P sources increased the P concentration in ear leaf to the critical range ≥ 0.2% in all three season...