Correção, fertilização fosfatada mineral e orgânica para latossolo vermelho distrófico típico do noroeste do Paraná

Abstract

The soil fertility and nutrient availability to plants is required to be obtained from the productive potential of crops. However, it is necessary to establish criteria, sources and combinations of fertilizer to be able to attend, ideally, the need for plants of commercial interest. This study was developed to study the efficiency of different correctives and organic and mineral fertilizers, in order to verify the ones that best represent the need for fertilization of a sandy Oxisol cultivated with corn and wheat. The essay was developed at the experimental station of the UEM - Umuarama, in pots of 200L, which were filled by a sandy Oxisol. It was applied, in pots, different organic fertilizers (6555kg ha-1 of poultry manure; 550m3 ha-1 vinasse), minerals (1028kg ha-1 of superphosphate; 1088kg ha-1 of magnesium thermophosphate), and combined rates of organic and mineral fertilizers (composed of organic ½ + ½ mineral from sources used). All applied fertilizers were associated to correctives of acidity of the soil, being them, limestone (1735kg ha-1) and calcium and magnesium silicate (1805kg ha-1). The control treatment was set without fertilization or correction of acidity. It was cultivated corn and wheat, evaluating leaf size, plant height and stem diameter for corn. For wheat, it was evaluated the plants height, leaf length, grain production of matter and whole dry plants, straw and grains. At the end of each culture it was sampled the soil of the vessels, determining the pH-CaCl2, Al3+, Ca2+, Mg2+, K+, P, and CECpH 7.0 estimating V%. The calcium and magnesium silicate were more efficient than the lime to increase the content of Ca2+ and correct the acidity of the soil in the 1st sampling. Both were equally effective corrective in the 2nd season of sampling. The application of vinasse corrected the acidity of the soil layer 10 - 20cm, increasing the concentrations of K+, Ca2+ and Mg2+, generating better development of corn. The thermophosphate, increased levels of P, Mg2+ and K+, but produced low growth of corn and wheat. The application of manure, simple superphosphate and thermophosphate increased the levels of available P in the superficial layer. The manure generated lower growth of corn and wheat improved performance when combined with mineral fertilizers.