Phosphorus recovery from different sources by pensacola grass inoculated with arbuscular mycorrhizae

Abstract

Agronomic phosphate source performance is dependent on its compositions, soil properties, plant species and microorganisms such as mycorrhizae. A greenhouse experiment, at the University of Santa Maria, RS, Brazil, was carried out to evaluate the agronomic efficiency of three different sources of phosphates in a typic paleudult soil, in a randomized 3 x 2 x 2 factorial design with four repetitions: (a) three phosphates (coarse granulated magnesium thermophosphate – MT, concentrated superphosphate – CS, and mixture of both – MI; (b) soil with and without liming; and (c) with and without G. clarum inoculation. The residual effects using samples of the same soil priorly cultivated with sorghum and the same experimental design were also estimated. The performing decreasing order in furnishing phosphorus of the sources was: CS, MI and MT. The inoculation with G. clarum promoted phosphorus recovery increase of MI and MT, but did not increase it when compared with CS, and the residual effect of MI was similar to CS. Inoculation promoted 29% dry matter yield in the first sowing and 34% as residual effect