Variação de atributos químicos de dois latossolos amarelos sob diferentes sistemas de manejo nos municípios de redenção e Paragominas-PA.

Abstract

The change of the use of the earth modifies along the time of cultivation the organic matter, as well as of the principal chemical elements in the soil, altering your chemical fertility, the time of implantation of the system of direct planting can recover these areas. Like this, the objective of this work was to evaluate the variation of chemical attributes of two Latossolos Amarelos under different handling systems in the municipal districts of Redemption and Paragominas-shovel. The work was developed in two areas and experimental areas, one in Fazenda Modelo, belonging to the producer Leonir Rozeto, located in the municipal district of Redenção and other in Fazenda Juparanã, in Paragominas, of the producer José Carminati. The experimental delineamento was installed in area of natural savannah and it kills in transition to the use of the earth for pastures and grains, it was maybe used blocks to the with subdivided portions, with four treatments T1 (I Prepare conventional under corn monocultivo), T2 (I Prepare conventional under soy monocultivo), T3 (I Prepare conventional under corn rotation and soy) and T4 (direct Planting: milheto/milho/soja), with three repetitions, in outline of subdivided portion (Split plot), where the portions understood the treatments, and the subparcelas the depths of sampling collection, each portion had dimensions of 100 x 36,50 m, and streets of 5 m between portions and 10 m among blocks, for 4 years (2000/2001; 2001/2002; 2002/2003 and 2003/2004). deformed soil samples were collected, in five collection depths: 0-5, 5-10, 10-20, 20-30 and 30-50 cm. These samples were analyzed at the laboratory of soils of Oriental Amazonian Embrapa, second methodology used by Embrapa, (2007). in agreement with the obtained results, the direct planting provided in Redemption and Paragominas, for four years of cultivation agricultural improvements in the chemical fertility of the soil evidenced by the increase in the tenors of organic matter, as well as the nitrogen, match, potassium, calcium, magnesium, sum of bases and capacity of cátions change the pH 7,0 and capacity of change of effective cátions. Also in the municipal district of Redemption and Paragominas the direct planting for four years provided the reduction of the acidity, evidenced by Al's smallest values, saturation for Al, potential acidity, and pH increase in the soil.