Soil acidity is one of the greatest problems faced in the management of agricultural lands around the world, mainly in the tropics, where phosphorus and nitrogen are also limiting factors. In the case of nitrogen, biological nitrogen fixation is the most economical and ecological alternative to decrease the use and impact caused by nitrogen fertilizers. Two “in vitro” experiments and one under greenhouse conditions using four Bradyrhizobium strains (BR 4406, BR 29, SEMIA 587 and INPA 03-11B) were carried out […]

Black oat provides an excellent soil cover, and is a preferential winter crop mainly before soybean cultivation in Rio Grande do Sul, Brazil. The objective of this study was to evaluate the effects of black oat straw management on soil cover, soybean emergency, soil temperature and soil water content. The experiment was carried out during 1997/98, at the Federal University of Santa Maria, Santa Maria (RS), on a Typic Hapludalf soil. A completely randomized block design was used in a […]

Losses of nutrients and organic matter due to hydric erosion are highly affected by soil management. Inadequate management systems may cause pollution and eutrophication of surface waters, fertilization cost increase, and ecosystems degradation. Nutrient and organic matter losses due to erosion were evaluated during six years on a very clayey Dusky Red Latosol, with a 0.03 m m-1 slope at Dourados, Mato Grosso do Sul, Brazil under natural rainfall conditions, and different soil management systems. The treatments applied in the crop succession […]

Alternative methods to correct soil acidity are needed because farmers who adopted no-tillage no longer want to plow soils to incorporate lime. Two experiments were carried out during the years 1993-1996 under no-tillage to evaluate the response of soybean, wheat, corn, oat and barley to lime applied on the surface of soils with 380 g kg-1 clay (LEd-Haplorthox) and with 580 g kg-1 clay (LRd-Haplorthox). A completely randomized block design, with three replications and seven treatments, was used. The treatments […]