Effects of types and levels of lime on chemical characteristics of soil and Tobiatã grass (Panicum maximum Jacq.)

Abstract

An experimental trial was conducted at FZEA/USP – Pirassununga SP Brazil, to evaluate the effects of type and level of limestone on soil and plant chemical compositions, applied on tobiatã grass, Panicum maximum Jacq. (Poaceae) pastures. Experimental design consisted of randomized blocks with seven treatments and four replicates, and composed of three types of limestone; Calcitic (A), Dolomitic 1 (C) and Dolomitic 2 (E) at two levels (V% = 30 e 60), plus control treatment. Soil chemical analyses were conducted between the second and third cuts, and plant chemical composition evaluated at the third. Limestone affected phosphorus, copper and manganese concentrations in the plant. At 0-20 cm soil depth there was lower concentrations of H+Al when C60% treatment was applied; on the other hand, concentrations of calcium, total base and aluminum saturation index were lower and independent from limestone type. Limestone application is a benefic and advisable practice since it balances nutrients in soil and plant