In soils under no-tillage (NT), the continuous crop residue input to the surface layer leads to carbon (C) accumulation. This study evaluated a soil under NT in Ponta Grossa (State of Paraná, Brazil) for: 1) the decomposition of black oat (Avena strigosa Schreb.) residues, 2) relation of the biomass decomposition effect with the soil organic carbon (SOC) content, the particulate organic carbon (POC) content, and the soil carbon stratification ratio (SR) of an Inceptisol. The assessments were based on seven […]

Grazing intensities can influence soil aggregation, which can be temporarily and permanently affected. The objective of this study was to evaluate the aggregate stability in water at the end of a soybean cycle and during pasture development in a crop-livestock integration system under no-tillage and grazing intensities. The experiment was initiated in 2001, in a dystrophic Red Latosol, after soybean harvest. Treatments consisted of pasture (black oat + Italian ryegrass) at heights of 10, 20 and 40 cm, grazed by young […]

The forms and availability of heavy metals in contaminated soils determine the uptake potential of plants and water contamination by leaching. In this study different methods of chemical extraction were used, in order to identify the forms of Pb, Cd, Cr, Ni, Cu, and Zn and evaluate the availability of these pollutants for sunflower (Helianthus annuus L.), black oat (Avena strigosa Schreber) (exotic species) and Bahiagrass (Paspalum notatum Flügge) (native species), as indicators, in soils of Pb mining and metallurgy […]

Cover plants have received extra attention due to their release of low molecular weight organic acids that form organic complexes with aluminum, calcium and magnesium. Besides neutralizing toxic aluminum, such compounds can increase the mobility in the soil profile of the dissolution products of lime applied on the soil surface. Objectives of this research were (a) to identify the low molecular weight organic acids found in different cover plant species and in soil solution, (b) to evaluate the effects of […]

Dynamics of decomposition and nitrogen (N) release of cover crop residues in mixed and single cultures was evaluated in a field experiment. The following materials were used: (a) black oat (Avena strigosa Schieb); (b) common vetch (Vicia sativa L.); (c) oilseed radish (Raphanus sativus L. var. oleiferus Metzg.); (d) 32 % black oat + 68 % common vetch, and (e) 51 % black oat + 49 % common vetch. To monitor the residue decomposition, air-dried plant material was inserted in 0.5 mm mesh nylon-bags (0.2 […]