QUALIDADE DE SOLOS SOB DIFERENTES TIPOS DE USO E MANEJO NO ESTADO DA PARAÍBA.

Abstract

The use and management, as well as the intensity and duration of use of soil cause changes in their properties, physical, chemical and biological, as well as the quality and degree of organic matter humification. This study aimed to evaluate the impacts of the type of land use, due to the substitution of the original vegetation cover, as the changes in its chemi-cal and biological attributes in semiarid regions and in the forest area of the State of Paraíba. In semiarid region soil samples were collected in three management systems: savanna vegeta-tion preserved (CP), savanna vegetation preserved with grazing goats (CPC), and cultivation of cactus pear (PF). The amostrgem was performed in the 0-5, 5-10 and 10-20 cm. Fractiona-tion of organic matter, total organic carbon, microbial biomass and total polysaccharides were executed. In the forest zone of the region, sampling was performed at the same depths and treatments were native area (MT), with pineapple monoculture with 30 years of agricultural use (A30), with pineapple monoculture of 20 years of agricultural use (A20 ); succession of crops, and fruit during 15 years, replaced by cane sugar (A15); pineapple monoculture for 10 years (A10), being conducted analysis of soil fertility and microbial biomass. In the semiarid region of cactus pear cultivation, produced the greatest concentrations of organic carbon in soil, higher than the caatinga and the calabash with grazing goats. CPF was shown a lesser degree of humification of organic matter with higher C content in the form of fulvic acids compared to humic acid fraction, since the levels of total polysaccharides were higher in the area of VCP. In the forest zone, treatment A30, where the incorporation of crop residues, promoted the highest levels of microbial biomass carbon. In general, the levels of nutrients suffered losses in areas where there has been a conservation soil management, and the A15 area is highlighted with respect to the contents of soil organic matter.