In order to be used in a program of inoculation, efficient arbuscular mycorrhizal fungi (AMF) must be able to cope with the indigeneous fungal population. An experiment was conducted under greenhouse conditions at the Embrapa Cassava and Fruit Crops in Cruz das Almas (BA), Brazil, with the objective to evaluate the competitive capability of selected fungi, using natural soil with Tainung no. 1 variety. A Yellow Oxisol with 3 mg dm-3 of available P was used. Three exotic and three […]

Soybean [Glycine max (L.) Merrill] inoculation and reinoculation are essential to guarantee the maximization of the biological N2 fixation process. Most inoculants commercialized for soybean in Brazil are peat-based, but there are doubts about the dose of peat inoculant which should be recommended, specially under stressing conditions or in areas previously inoculated. Therefore, for the central region of Brazil, the recommendation is 1.000 g of inoculant/50 kg of seeds, with a sugar cane solution as adhesive. However, in this study […]

Soil loss tolerance refers to the maximum rate of annual soil loss that will permit crop productivity to be obtained economically and indefinitely. Besides the usual form, it can also be used in the Universal Soil Loss Equation as a criteria to better define terrace spacing on croplands. This research work was developed during 1998, at the Agroveterinary Center/UDESC, in Lages, Santa Catarina, Brazil, to establish soil loss tolerance values by water erosion for 73 soil profiles of Santa Catarina, […]

Soil water infiltration rate, together with rainfall rates determine runoff rates, being an important parameter for erosion estimation and soil conservation studies. Measurement of infiltration rates can be performed using a double-cylinder device (CD) or a rotating-boom rainfall simulator (RS). The use of CD is less laborious in comparison with RS instruments, but results often do not agree with rates occurring in real rainfall situations, possibly due to surface crust formation. Crust formation depends both on factors that do not […]

Different sites of an iron mining from Mariana, Minas Gerais, Brazil, were evaluated for determining the degree of their degradation or reclamation, using microbial activity of soil, spore numbers of arbuscular mycorrhizal fungi (AMF) and total count of fungi and bacteria. Each site contained a substrate characterized as flotation refuse (Rj), Soil without vegetation (SS), Subsoil (Ss), Subsoil with vegetation (SsV), site under recuperation (AR) and forest (MS), and was sampled at 10-25 cm. Establishment of grasses and “candeia” (Vanillosmopsis […]

An empirical equation to represent the analytical soil particle-size curve is proposed. Based on this equation, a new expression was obtained to calculate the predominant mean diameter of soil particles, which represents the mean size of these particles. The equations can be applied, advantageously, in soil physics as well as in geological, geomorphological and sedimentological studies.

In this study, a first order exponential model was adjusted to the experimental data of soil organic carbon (OC) and total nitrogen (TN) of a 9-year-old experiment in southern Brazil. Parameters of soil organic matter dynamics were determined and the soil OC and TN stocks simulated in a Paleudult soil under three tillage systems (conventional tillage: CT, reduced tillage:RT, and no-tillage:NT) and three cropping systems (oat/maize-O/M, oat + vetch/maize-O + V/M and oat + vetch/maize + cowpea-O + V/M + […]

The determination of soil potential acidity (H + Al) extracted by the 0.5 mol L-1 calcium acetate solution is a routine analysis in Brazilian soil laboratories. However, due to analytical facilities, it is becoming a regular procedure to estimate the values of potential acidity using the equilibrium pH of the soil suspension with the SMP solution. The aim of this study was to look at the relationship between pH SMP and H + Al in soils of Pernambuco, in order […]

The use of mineral fertilizers and legumes is the most important strategy used to supply nitrogen for cash crops. Since there is a risk of environmental pollution by nitrogen fertilization, it is very important to improve the approaches of nitrogen use recommendation to achieve sustainable agricultural practices. The organic matter content has been used as a parameter to estimate N availability, but in some cases it has been inefficient. In order to develop an equation to estimate N availability in […]

This study evaluated the molecular weight (mw) as well as the proportions of humic and fulvic acid fractions in humic substances (H5) extracted with 0.1 M NaOH and a chelating (Chelex 100 chelating ion exchange resins) (Na form), via High-Performance Size Exclusion Chromatography (HPSEC). Samples of a Dusky Red Latosol were collected from three areas: under orange-cultivated forest with and without liming. Standards of sodium polystyrene sulfonate and acetone were used to calibrate the molecular weight and retention time ratio. […]