ABSTRACT Autumn maize intercropped with tropical forages can raise the amount of crop residues and improve nutrient cycling, favoring subsequent soybean crop. The objective of this study was to evaluate the effect of forms of implementation of intercropping of irrigated autumn maize with tropical forages on yield, decomposition, nutrient accumulation and release, and on the ratio of lignin/total N of forage residues, yield components, and grain yield of subsequent soybean, and on soil physical and chemical properties, under no-tillage in […]

Knowledge of the dynamics of decomposition and nutrient release in production systems is of great importance for management of soil fertility and reducing waste of resources. In this regard, an experiment was conducted in Cerrado (Brazilian tropical savanna) soil from the western region of Bahia, Brazil, for the purpose of studying the decomposition and nutrient release from corn stover plus Brachiaria ruziziensis straw under an integrated crop-livestock system. The evaluations were performed using litterbags collected at 0, 15, 40, 110, […]

Hygroscopic fertilizers tend to absorb moisture from the air and may have undesirable characteristics such as moistness, clumping and lower fluidity, hampering the application. The increasing use of urea is due to its numerous advantages, although this nitrogen (N) source is highly susceptible to volatilization losses, particularly when applied to the soil surface of management systems with conservation of crop residues. The volatilization losses can be minimized by slow or controlled-release fertilizers, with controlled water solubility of the urea-coating materials; […]

The application of organic residues to the soil can increase soluble organic carbon (SOC) and affect the pH and electrolytic conductivity (EC) of the soil. However, the magnitude of these changes depends on the type of residue and the applied dose. This study aimed to evaluate the effect of increasing C rates contained in organic residue on the pH, EC, water-extractable total carbon (WETC), water-extractable organic carbon (WEOC), and water-extractable inorganic carbon (WEIC) in soil treated with manure (chicken, swine, […]

Several factors determine the selectivity of the soil erosion process by rainfall concerning the size of eroded-sediments transported in the runoff water. Among them, it is important to point out the intensity of the rainfall and its associated runoff, the texture and degree of consolidation of the soil surface layer, the form of erosion (interill, rill, or gully), the microrelief of the terrain or surface roughness created by tillage, and the size and stability of the soil aggregates. Considering that, […]

The use of pig slurry in no-tillage systems on cultural residues with high C/N ratio is becoming a common practice in the center-south of Brazil. Two experiments were conducted to evaluate the immobilization of ammonium N applied with pig slurry to the soil. One experiment was run in the field and the other in laboratory conditions, both on a Hapludalf soil. The treatments consisted of pig slurry application with and without oat straw, with (reduced tillage) and without (no-tillage) soil […]

The quality of commercial crop residues and green manure influences the N mineralization-immobilization rate and the respective use by subsequent crops. With the objective of evaluating N utilization by corn of N from the shoot and root system of sunnhemp (Crotolaria juncea) and millet (Pennicetum americanum) and corn straw, labeled with 15N, a green house experiment was carried out at the Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, S. Paulo, Brazil, in 5 kg pots with dystroferric Red Latosol […]

The application of animal manure to the soil, particularly those generated in pig farms, has become an increasingly common practice in southern Brazil. However, depending on the dose applied, there is a risk of nutrient losses, mainly nitrate (NO3–), to the water courses through leaching and runoff, and to the atmosphere as N-oxide emissions. The objective of this work was to evaluate the accumulation and displacement of N-NO3– in the soil after pig slurry application in no-tillage corn. The doses […]

Inadequate soil management has led to the degradation of physical, chemical and biological soil properties. The purpose of this work was to evaluate the yields and physical and chemical soil properties of a dystropherric Red Latosol (Oxisol) in the third year of a crop rotation that included green manures, with soybean or corn (summer) and common bean (winter) crops. The following green manure species were used: velvet bean, millet, sunnhemp, pigeon pea, cultivated under conventional tillage and recently adopted no-tillage. […]

The dynamics of nitrogen in soils under no-tillage in Southern Brazil are poorly studied so far. A field experiment on a typic Hapludalf on the experimental area of the Soil Science Department, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul State, Brazil, was carried out in 1998/99 and 1999/00 to evaluate the effect of single crop and mixtures of black oat (BO) (Avena strigosa Schieb), common vetch (CV) (Vicia sativa L.) and oilseed radish (OR) (Raphanus sativus […]