Formas de fósforo, cobre e zinco em latossolos de Mato Grosso de diferentes texturas, adubados com dejeto de suíno

Abstract

The use of fluid pig slurry as a source of nutrients, in areas with crops, it presents itself as a viable alternative for disposal of this waste. However, the application of pig slurry may influence the availability of phosphorus, zinc and copper in the soil. The present study was divided into two chapters, the first one aimed to evaluate the influence of increasing doses of pig slurry on available P, Zn and Cu contents and to compare the extraction methods for available P, Cu and Zn. Soil samples from the Oxisols class were collected in the 0 to 0.20 cm layer. The samples, packed in plastic bags, received six doses of pig slurry (0; 50; 150; 300; 450 and 600 m3 ha-1 ) in three repetitions, during 45 days. In addition to the soil fertility attributes, the available P was determined by extractors Mehlich-1, 3 and distilled water and the labile and moderately labile forms of P. Were also determined the Zn and Cu available were also determined by extractors Mehlich-1, 3 e HCL. The data were submitted to regression and correlation analysis. The application of increasing doses of pig slurry increased the levels of P, K, Cu and Zn available in all Oxisols evaluated. In the extraction of available P and Cu there was a high correlation between the Mehlich-1 and 3 extractors. In the Zn extraction, a high correlation was found between the three evaluated extractors (Mehlich-1, 3 and HCl). Chapter 2 aimed to evaluate the forms of Zn, Cu and P accumulation in soils subjected to successive pig slurry applications. Samples of soils of different textures were collected in areas with and without a history of pig slurry use, in the 0 to 0.10 and 0.10 to 0.20 m layers. The total and available levels of P, Zn and Cu and the fractions of P, Zn and Cu were analyzed; labile, moderately labile fractions and the residual fraction. The results were analyzed using the Kruskal-Wallis test, correlation analysis and principal components. There was no predominance of more labile P forms compared to non-labile forms, when areas with and without pig slurry were compared. The use of pig slurry as fertilizers in the soil can mainly change the forms of Zn in the soil, as there was a greater amount of Zn in the forms available in areas with longer time of use pig slurry.