Chemical control of green cover crops is common in no-till systems and nutrient mineralization of the residues left on the soil surface can be intensified by rainfall over time after the plant desiccation. Potassium leaching from six green cover crops was evaluated as affected by rainfall simulated at different stages after the herbicide application. Pearl millet (Pennisetum glaucum), guinea sorghum (Sorghum vulgare), black oat (Avena strigosa), triticale (Triticum secale), Indian hemp (Crotalaria juncea), and brachiaria (Brachiaria decumbens) were grown under […]

The establishment of herbaceous perennial leguminous in production systems is still a challenge, mainly because of the slow initial growth. Evaluations of the soil cover ratio, dry matter production, contents and accumulations of nitrogen, phosphorus, and potassium of the herbaceous perennial Galactia striata and Pueraria phaseoloides, sown in different densities and row spacing, aimed at making their establishments feasible. The experiment was conducted in December/98 at Embrapa Agrobiologia, Seropédica (RJ), in a completely randomized block design, as a factorial arrangement […]

Besides protecting soil from erosion, plant residues left on the soil surface by green cover crops in no-till cropping systems represent a considerable nutrient source of nutrients that can be made available for the following crop. Potassium leaching from the straw of six cover crop species was evaluated, in relation to the amount of rain on the residues. Pearl millet (Pennisetum americanum), guinea sorghum (Sorghum vulgare), black oat (Avena strigosa), triticale (Triticum secale), Indian hemp (Crotalaria juncea) and brachiaria (Brachiaria […]

Spontaneous plant species in agricultural areas have been regarded as weeds, invasive or unwanted plants, when considering the damages that they can bring to cultivated species. However, spontaneous species can bring about the same effects of soil protection and nutrient cycling that cultivated or introduced species used for green manure do. Biomass productivity and nutrient accumulation for the aerial part of spontaneous and leguminous plants used as green fertilizers were measured at the experimental station Embrapa Corn and Sorghum, in […]

The objective of this study was to evaluate the relation between the chemical composition of litter accumulation and its effect on the physics and fertility of soil in two plantation systems of native forest species. The plantation systems consisted of 22 year-old mixed stand and pure stands of six hardwood species (Peltogyne angustiflora, Centrolobium robustum, Arapatiella psilophylla, Sclerolobium chrysophyllum, Cordia trichotoma, Macrolobium latifolium) native to the southeastern region of Bahia, Brazil, evaluated from August 1994 through November 1996. As a […]

Agroforestry systems combine crop productivity with environmental sustainability while conserving fertilizer through nutrient cycling. Plant biomass production and nutrient inputs were measured in an alley cropping system and in native cerrado site at Botucatu, State of São Paulo, Brazil, and the influence of agroforestry practices on the soil chemical attributes were determined. Leucaena was planted in 1987, in hedgerows 6 m apart, following lime and P applications. Legume hedgerows were pruned annually, allowing for cereal intercropping of rye with oat […]

The nutrient cycling of two types of vegetation, (a “low forest” – 15 m of height, and a “short forest” – 25 m of height), characteristic of the sandy belts on the Coastal Plains of Ilha do Mel was studied, from June 14th, 1991 to June 12th, 1993. In this first step the soil’s chemical and physical characteristics were studied, in relation to the physical environment and the parent material. The soils were classified as allic/dystrophic podzols, where the B […]