Qualidade do solo em sistemas de produção de hortaliças orgânico e convencional

The soil is one of the most important sustainability columns of the production system. The integrated analysis of the edaphobiological attributes can be an important tool for soil quality evaluation. We evaluated the soil quality regarding the adopted agriculture practices, using the integrated analysis of physical, chemical and biological attributes. The research was carried out in Ibiuna and Socorro, Sao Paulo state, Brazil, in organic and conventional production, on small and family farms. Physical, chemical and biochemical parameters were evaluated during 2006 and 2007 in soils under vegetable cultivation, native forest or fallow, taken as reference of natural soil. Agricultural practices data were collected in each production system. The obtained data were submitted to principal component analysis (PCA). There was no pronounced grouping trend according to the production system, organic or conventional, but there was a grouping according to the soil use (forest/fallow land or cultivation). The PCA identified greater degree of similarity between Socorro's cultivation soil and its respective controls compared to Ibiuna's soil, clearly separated according to its use (forest or cropping), indicating better soil management in Socorro. In general, the results allow to conclude that agricultural practices in most of both organic and conventional production systems, caused soil degradation, due to, mainly, intensive soil tillage and no soil mulching, as indicated by the reduction of soil organic matter, microbial biomass, plant emergence and aggregate stability in cultivated areas relative to control ones.