Silicato de magnésio e bioativador na produtividade de Urochloa e de trigo

Abstract

Magnesium silicates, among them the serpentinite, can provide several elements important for plant nutrition, among them silicon that can increase the persistence of cultural residues on the surface. With this aim, we tried to evaluate the action of the serpentinite in the dry matter production of the aerial part of the forage Urochloa brizantha cv. Piatã, decomposition of forage phytomass and development of wheat grown in succession. The experimental design used was randomized blocks in subsubdivided plots in time, with serpentinite doses in the plots (0, 2, 4, 8 and 16 Mg ha- 1), the use of bioactive in the subplots (with and without the use of bioactive) and the epochs of evaluation in the subsubparcels (0, 30, 60, 90, 120 and 150 days after the management). The variables analyzed were: phytomass cover rate, soil remnants of phytomass of forrageria, half - life and forage phytomass decomposition constants, foliar concentrations of nutrients and silicon in wheat crop, soil chemical attributes and components of wheat crop yield. The application of the serpentinite provided higher productivity of dry matter of Urochoa brizantha cv. Piatã, increased the rate of cover and remaining mass of the Urochloa phytomass on the soil, improved the chemical attributes of the soil and favored the increase of the dry mass, number of ears and yield of the wheat crop. The use of the bioactive caused acidification of the soil, with reduction in base saturation, organic matter content, phosphorus and zinc. The bioactive also provided higher production of Urochloa dry matter with lower doses of serpentinite.