The effect of N applications (time and rates) on chlorophyll and N contents in bean leaves was evaluated and correlations among them and with the yield established. Carried out in the Selvíria region, State of Minas Gerais, Brazil, the experiment was set up in a completely randomized block design in a factorial 3 x 5 scheme. Treatments consisted in the combination of N (urea) application by side dressing at five levels (0, 35, 70, 105, and 140 kg ha-1 of N) at three times […]

The iron oxide mineralogy of sand, silt and clay fractions was studied in five soil materials. Samples were collected from a pedon of a Red Nitossolo (Brazilian Soil Classification; related to an Alfisol in US Soil Taxonomy) developing on a tholeiitic basalt, near the town Tupaciguara (18 o 35 ‘ 33 ” S; 48 o 42 ‘ 18 ” W) in the region of Triângulo Mineiro, state of Minas Gerais, Brazil. Portions of sand and silt were analyzed by magnetic separation and selective chemical treatments with NaOH […]

To evaluate a fractionation scheme for Zn in a sandy soil (Ultisol) and its relation with Zn availability for Cynodon spp cv. Tifton-85, an experiment was carried out in greenhouse, with a factorial scheme (5 doses of zinc, 2 doses of lime and 2 times of sampling), in a completely randomized block design, with three replications. The doses of Zn were: 0; 2.5; 5.0; 7.5 and 10 mg dm-3; half of the pots did not received liming (V = 42%) and, in the other half, liming was […]

Primavera do Leste is one of the most important farming areas of Mato Grosso State. This study was carried out in a Red-Yellow Latosol to evaluate the microbial biomass and enzyme activities in soils under native vegetation (known as “Cerradão”) and in soils under annual and perennial cropping systems. Soil samples were collected, at the beginning of the rainy season, at two depths (0-5 and 5-20 cm) in areas under a vineyard (row and between rows), annual crops (soybean) and native […]

In this study the split application of nitrogen and the maize crop pre-sowing nitrogen application under a no-tillage system followed by black oat, with two rainfall regimes were evaluated. Treatments were: (a) application of 150 kg ha-1 of N in pre-sowing and 30 kg ha-1 of N at sowing with 1997/98 “El-Niño” rainfall applications; (b) nitrogen application, being 30 kg ha-1 of N at sowing, and 30 kg ha-1 of N at 31 and 57 days after emergency (DAE), with “El-Niño” rainfall applications; (c) without N application and “El-Niño” […]

Properties of a claim loam soil, collected in Aranjuez (Madrid) and enriched with organic matter and microorganisms, were evaluated under controlled temperature and moisture conditions, over a period of three months. The following treatments were carried out: soil (control); soil + 50 t ha-1 of animal manure (E50); soil + 50 t ha-1 of animal manure + 30 L ha-1 of effective microorganisms (E50EM); soil + 30 t ha-1 of the combination of various green crop residues and weeds (RC30) and soil + 30 t ha-1 of the combination of […]

The distributions of microbial biomass carbon (MBC), enzymes activities and readily mineralizable carbon were evaluated across soil aggregates recovered from a Dark-Red Clayey Oxisol in areas under native Cerrado vegetation and where no-tillage (NT) and conventional tillage (CT) management systems have been established for 21 years. Soil samples were collected at a 0 to 5 cm depth and aggregates were prepared using a wet sieving procedure. The size classes 8.0 to 2.0 mm, 0.5 to 0.25 mm and 0.25 to 0.106 mm and samples denominated […]

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 […]

The use of the pH SMP to estimate the potential acidity has advantages in relation to the 0.5 mol L-1, pH 7, calcium acetate method, but it requires previous edaphic regionalization to estimate the H + Al values with safety. In the northwestern region of the State of Paraná there are soils originally developed from sandy sedimentary rock of the Caiuá Formation, called Caiuá Sandstone, of the Cretaceous period. These soils are characterized by low contents of clay and organic matter, and a low buffer capacity, […]

Soil moisture content, determined by the moisture equivalent method (ME), is associated with field capacity (FC) in temperate soils. The FC matric potential of soils developed under tropical and humid conditions has higher values, in the range of -10 to -6 kPa. To establish a relationship between FC of Oxisols and Quartzipsamments with ME a review of M.S. and Ph.D. theses submitted to the faculty of the Federal University of Viçosa, Brazil, was done. Appropriate data should include soil classification, clay […]