Influence of minjingu phosphate rock application on tephrosia vogellie fallow productivity and subsequent maize response on a ferralsol in morogoro,Tanzania

The objectives of this study were to quantify the response of /'. vogelii fallow to Minjingu Phosphate Rock (MPR) application at establishment on quantity and quality of biomass produced. P availability, total inorganic-N. maize yields, and pH and Ca changes on an acidic. I’ deficient Ferralsol. The data w'ere collected from pot. incubation and field experiments. The pot studies were used to assess response of T. vogelii seedlings to MPR. P and Ca applications, and that of maize to 7'. vogehi biomass and MPR applications Incubation experiments were used to evaluate the influence of MPR application on decomposition of 7'. vogelii biomass and N release. and the effects of combined application of MPR and T. vogelii biomass on Pi-P. The field experiments were used to evaluate the effects of MPR application at fallow­ establishment on /' vogelii performance, maize response to fallow' biomass and MPR applications, and to residual MPR and fallow biomass and fresh biomass applications. In soil of pH 5.9. the quantity, quality and Nz-fixing capacity of T vogelii seedlings were significantly improved relative to pH 5.0. Application of MPR improved these parameters at both values of soil reaction. The quality and quantity of 7'. vogelii biomass depended on P application. Combined application of T. vogelii biomass and MPR significantly increased maize DM yield in the pot and field studies, but depressed Pi-P in the incubation study. Decomposition of T. vogelii biomass was significantly increased only in the first 28 days by MPR application and was not effected thereafter. Minjingu PR application at fallow establishment significantly increased the quantity and quality of T. vogelii biomass, total inorganic- N and Pi-P in the fallow's. Subsequent to fallows, application of T. vogelii fallow'Ill biomass or combined with MPR significantly increased total inorganic-N. The Pi-P. earleaf N and P concentrations, soil pH. exchangeable Ca and maize yields were significantly increased by application of MPR at fallow establishment and by combined MPR with fallow biomass It is concluded that application of MPR on a strongly acid P deficient Ferralsol improves the quantity and quality of T. vogelii fallows and subsequent maize yields

Tanzania Agricultural Research Project Phase II and African Academy of Sciences