Revista Brasileira de Ciência do Solo
Print version ISSN 0100-0683
PANDOLFO, Carla Maria; CERETTA, Carlos Alberto; VEIGA, Milton da and MASSIGNAM, Angelo Mendes. Nutrient sources associated with soil tillage systems: technical aspects. Rev. Bras. Ciênc. Solo [online]. 2008, vol.32, n.2, pp. 759-768. ISSN 0100-0683. http://dx.doi.org/10.1590/S0100-06832008000200030.
Manure has been used as organic nutrient sources in different soil, climate, crop, and soil management systems. The effects of the continuous use of these systems is best evaluated by integrated analysis, based on different soil and crop attributes. This study was carried out to compare nutrient sources, mainly the organic ones, based on some chemical and physical soil attributes as well as crop attributes. The study was carried out at an experimental station of Epagri in Campos Novos, on a Typic Hapludox, in a long-term experiment. The treatments were a combination of five tillage systems (no-till, chisel plow, conventional tillage, conventional tillage with burned crop residues, and conventional tillage with crop residues removal) with five nutrient sources (TES = control, without fertilizer; AM = mineral fertilizer according with technical recommendation for each crop; CA = 5 Mg ha-1 year-1 of moist poultry litter; DLB = 60 m3 ha-1 year-1 of liquid cattle manure; and, DLS = 40 m3 ha-1 year-1 of liquid pig manure). A model was established to evaluate the nutrient sources use. The model was fed data of soil and crop attributes, that were transformed into the respective indexes. A model was used to quantify and analyze the effect of nutrient sources on technical aspects of each soil management type. The outputs were triangular pictures and their areas, with the respective confidence limits (p < 0.10). The nutrient sources did not differ when the plant, chemical and physical indexes were considered together, whereas results of poultry litter were best when evaluated by the chemical or the plant index. The technical behavior of the nutrient sources and the physical index in particular were related to soil tillage. Among the evaluated tillage systems, no-till performed best and the conventional system with straw removal worst. The model used to analyze the technical aspects was an efficient tool for a more comprehensive evaluation of the use of organic nutrient sources.
Keywords : manure; fertilization; analysis model; soil indexes.