Efeito da adubação com silicato de cálcio e magnésio sobre o desenvolvimento e a produtividade do milho

Abstract

Silicon (Si) is considered beneficial micronutrient to higher plants, which may have effects on crops, when it provides the plant greater resistance to attack by diseases, pests and insects as well as higher grain yield. Thus, new commercial products arise in trying to increase production, plus other benefits to the plant. This is the case of fertilizers having the silicon as a constituent element, such as silicates of calcium (Ca) and magnesium (Mg). Thus, the use of silicates of Ca and Mg in the form of a mixture of powdered rock, has emerged as an alternative for increasing the content of Si, and contribute to the availability of phosphorus in the soil. However, as their action in maize (Zea mays) when applied to the soil there is a certain lack of information. Therefore, the aim of this study was to evaluate and discuss the effect of silicon rich natural fertilizer application doses and times, at sowing and topdressing on the development and productivity of maize, besides its effect on the availability of phosphorus in the soil, in the off-season and 2014. The experimental design was a randomized block design (RBD) with four replications. Treatments are two doses (200 and 400 kg / ha) of calcium silicate and magnesium, which is a natural fertilizer derived from the powder mixture of rocks, besides the application at seed furrows, at sowing surface coverage in the V4 stage (4 expanded leaves) and a control without fertilizer application. The analyzed variables are the Ca, Mg, P, K, Si in the soil before and after cultivation, plant emergence, vegetative parameters as indicators of development, plant height, stem diameter, leaf area index during flowering, first spike insertion height, number of grains per spike, 100-grain mass and grain yield. The results demonstrate that there was no significant difference relative from the effect of treatments used, at both vegetative parameters and productivity of corn grains. The average content of macronutrients (N, P, K, Ca and Mg) at corn leaf also presents no significant difference. On the ground, the analyzed chemical attributes showed similar results to each other. It can be concluded that the use of calcium silicate and magnesium was not efficient for the cultivation of the second harvest of corn.