Estratégias de manejo de solo para transição agroecológica em horticultura

Abstract

Agroecology is a scientific field that guides sustainable practice of agriculture, which is a process of conversion from traditional to more sustainable practices based on adoption of conservation management techniques and the optimized use of inputs. Straw over the soil is one basic practice, although not prevalent due to the farmers habit of preparing the soil between crops for weed removal, soil decompaction and incorporation of fertilizers. Therefore, this study aims to identify the effects of management and land cover on soil quality and socioeconomic aspects in a horticultural production system going through agroecological transition. The experiment was carried out on a farm in Santana do Livramento – RS. The treatments used were based on combinations between the use of cover crops straw and preparation of the soil: i) without cover and with tillage (T1); ii) no cover and no tillage (T2); iii) covered and no tillage (T3); and iv) covered and with tillage (T4). For soil cover, black oat straw (Avena strigosa Schreb.) was used in winter and alexandergrass (Brachiaria plantaginea) in summer. The chemical evaluation consisted of analyzing the attributes of acidity and nutrient availability. The microbiological variables analyzed were microbial activity (basal respiration) and population of free-living nematodes and phytoparasites. Soil loss was analyzed by height lowering beds measurements. Productivity and labor costs were analyzed in each treatment. P and K soil contents, the acidity components, and sum of bases were sensitive chemical indicators to measure soil changes. No tillage and soil cover (T3) showed greater activity of microorganisms and a higher population density of free-living nematodes, as opposed to treatment with tillage and without soil cover (T1). The covering maintenance protected against soil loss and without impact on labor or productivity. Soil management strategies with maintenance of cover and no till, based on agroecological transition, improved soil quality and provided socioeconomic benefits.