Dry matter production by two species of plants due to application of phosphate fertilizers in a degraded soil

Abstract

A greenhouse experiment was carried out at the Department of Agronomy - Universidade Estadual de Maringá. Surface soil material was sampled from a degraded area at Fazenda Experimetal de Iguatemi which presented unfavourable chemical characteristics such as low organic matter content, low pH, low phosphorus content and a toxic level of aluminium. In these soil samples the effect of phosphate fertilisers on the growth of two species of different plants: soy bean (Glycine max) cv. BR-37, and capim brizantão (Brachiaria brizantha) cv. Marandu were studied. Different sources of phosphorus fertilisers were used, being three from natural origin and classified as of high agronomic efficiency (Arad, North Caroline, and Gafsa), and a highly soluble (super simple phosphate). The fertiliser that promoted the largest dry matter production was the super simple phosphate, due to its high solubility and readiness to be absorbed, and/or for simultaneous sulphur supply in sulphate form. There was no difference in the dry matter production between the natural fertilisers. Soy bean developed better with the natural sources. This can be explained by its different capacity to dissolve the natural sources, since soy bean tends to lower rhyzosphere pH than Brachiaria brizantha.