Especially under no-tillage, subsuface soil acidity has been a problem, because it depends on base leaching, which has been associated with the presence of low molecular weigth organic acids and companion anions. The objective of this study was to evaluate exchangeable base cation leaching as affected by surface liming along with annual urea side-dressing of maize and upland rice. Treatments consisted of four lime rates (0, 1500, 3000, and 6000 kg ha-1) combined with four nitrogen rates (0, 50, 100, […]

To mitigate soil erosion and enhance soil fertility in orange plantations, the permanent protection of the inter-rows by cover species has been suggested. The objective of this study was to evaluate alterations in the microbial biomass, due to different soil tillage systems and intercropped cover species between rows of orange trees. The soil of the experimental area previously used as pasture (Brachiaria humidicola) was an Ultisol (Typic Paleudult) originating from Caiuá sandstone in the northwestern part of the State of […]

Sequential extraction allows more detailed information about the origin of heavy metals in natural environments, their mode of occurrence, biological and physico-chemical availability, mobilization and transport. To study the Pb and Zn forms, eight soil profiles were selected at different sites within a Pb mining and metallurgy area in the city of Adrianópolis, state of Paraná, in the Rio Ribeira valley. Samples were collected from the layers 00-10, 10-20 and 20-40 cm. The total Pb and Zn contents and their […]

Nowadays the concept of soil physical quality is well-established, based mainly on the indices that quantify soil quality. The S index is a new indicator of soil physical quality related to important soil characteristics. The purpose of this study was to evaluate the method of obtaining the S index and the derivative of the function of the of water retention curve, using the transformation ln(h) or not, and assess the problem of units and the restriction m = 1 – […]

To mitigate the impacts of eucalypt monoculture, forestry companies in the Upper Jequitinhonha Valley (MG) have adopted the insertion of strips of native vegetation in-between the commercial plantations. The method used for the creation of these corridors is to allow spontaneous regrowth of native vegetation in areas previously under eucalypt. The objective of this study was to evaluate the effect of cover crops on microbial and soil properties for a detailed description of the restoration process of native vegetation in […]

Soil compaction can be minimized either mechanically or biologically, using plant species with vigorous root systems. An experiment was carried out with soybean (Glycine max) in rotation with triticale (X Triticosecale) and sunflower (Helianthus annuus) in fall-winter associated with pearl millet (Pennisetum glaucum), grain sorghum (Sorghum bicolor) or sunn hemp (Crotalaria juncea) in spring. Crop rotation under no-till was compared with mechanical chiseling. The experiment was carried out in Botucatu, São Paulo State, Brazil. Soil quality was estimated using the […]

Ravines represent one of the formations resulting from water erosion, with concentrated surface water flow down hillsides of degraded areas, yet without subsurface water flow. The objective of this study was to evaluate hydraulic flow conditions in ravines as well as to determine soil erosion resistance parameters: soil erodibility (Kr) and critical shear stress (τc) on the ravine surfaces, as well as to determine soil erodibility at several depths of degraded hillsides along the coastline of the state of Pernambuco. […]

Weed control is one of the most intensive management practices in coffee plantations resulting in changes in soil chemical properties. The objectives of this study were: a) to assess the effects of weed management in a coffee plantation on the chemical properties of a Dystroferric Red Latosol (Oxisol) compared to soil under native forest; b) to verify the relationship between soil organic carbon content (COS) and the effective cation exchange capacity (effective CEC) and the cation exchange capacity at pH […]

The use of manure in agricultural system is a possibility to dispose of the waste generated in animal production, but improper use can cause environmental problems. The general objective of this study was to evaluate carbon and nitrogen concentrations and losses in runoff in four doses of liquid dairy manure (0, 60, 120, 180 m3 ha-1 yr-1) applied to a silt clay loam Oxisol with 13 % slope, in no-till with soybean, oat, corn, and wheat in crop rotation. The […]

Peats are an important reserve of humified carbon in terrestrial ecosystems. The interest in the use of humic substances as plant growth promoters is continuously increasing. The objective of this study was to evaluate the bioactivity of alkaline soluble humic substances (HS), humic (HA) and fulvic acids (FA) isolated from peats with different decomposition stages of organic matter (sapric, fibric and hemic) in the Serra do Espinhaço Meridional, state of Minas Gerais. Dose-response curves were established for the number of […]