Uso de fontes de fósforo e silício em arroz inundado

Abstract

Brazilian Cerrado soils are characterized by low natural fertility, low phosphorus availability, in addition to high P correction capacity, caused by high levels of iron and aluminum oxides, with P being one of the nutrients that most limit crop productivity. The aim of the present study was to evaluate the agronomic efficiency of MAP sources with and without sulfur and their combination with a source of Si in cultivated flooded rice plants in soils of different sandy and clayey textures under greenhouse conditions. The experimental design used was randomized blocks (DBC) in a triple factorial scheme (3x2x2+2) with four replications. The factorial design consisted of the use of three doses of P2O5 (0, 50, 100 and 150 kg ha-1 ) x two sources of MAP with and without sulfur (common MAP and MAP + S) x with or without Si + two additional ones, being a control with and another without Si (both without P2O5) and two rice crops were carried through, in order to evaluate the residual effect of the sources. It was observed that the increase in doses, regardless of the phosphate source used, was efficient in increasing the production of MSPA, the P contents in the plants, the accumulation of P and Si, as well as the P contents in the soil, in the first and second crop, in both sandy and clayey soils. The use of silicon fertilization increased the efficiency of phosphate sources, both in the first and in the second cultivation, in both sandy and clayey soils. Also, in the average between treatments with and without silicon, there was an increase in silicon in the plants.