Atributos do solo sob manejos agrícolas camponeses.

Abstract

Soil is a component of the biosphere with local, regional and global effects, exercising functions essential to life. Soil degradation represents a threat to food production systems and puts into question the importance of agricultural systems. Therefore, alternative agroecosystems, especially in the context of peasant agriculture, must be discussed. The agroforestry system, for example, can contribute to the improvement of soil health and ecosystem services, enabling more sustainable agriculture. The objective of this work was to evaluate the quality of the soil in agricultural managements, with peasant agriculture as the basis. The study was conducted in the Emiliano Zapata pre-settlement, municipality of Ponta Grossa - PR. The climate of the region is classified as Cfb and the soil as Red-Yellow Latosol. Three areas of the property with the same soil textural class were chosen and characterized by types of management: agroforestry (AF), vegetable garden (H) and crop (L). Samples were collected in the 0-10 cm layer for the chemical attributes of pH, potential acidity (H+ + Al3+) and calcium, magnesium, potassium, phosphorus, organic carbon and aluminum contents, biological microbial biomass carbon, soil basal respiration, microbial quotient and metabolic quotient and structural weighted mean diameter (WAD), macroaggregates of different size classes and microaggregates. In the 0-10 and 10-20 cm layers saturated hydraulic conductivity (Ksat) density, total porosity, and distribution of macro, micro, and biopores were measured. The Rapid Soil Structure Diagnosis (SSSD) was also performed. For the physical variables, with the exception of ESRD and DMP, chemical variables, with the exception of H++Al3+, base sum and V%, and biological variables, with the exception of qCO2 and qMIC, we performed multivariate principal component analysis (PCA). The principal components analysis method indicated that there are three groups with different variability that coincide with the AF, H and L management. AF presented the highest organic C, CTC at pH 7, base sum and V%. The best visual quality of soil structure was observed for agroforestry, as well as the highest DMP and the highest percentage of large macroaggregates, which were lower for tillage and vegetable garden. The Ksat was higher for AF in relation to L. The microbiological attributes indicated, higher BMS-C and qMIC and lower RBS and qCO2 for L, AF and H did not differ for RBS and AF presented the lowest values of BMS-C and qMIC. AF showed better physical and chemical attributes while L showed better biological attributes.