The N use by maize (Zea mays, L.) is affected by N-fertilizer levels. This study was conducted using a sandy-clay texture soil (Hapludox) to evaluate the efficiency of N use by maize in a crop succession, based on 15N-labeled ammonium sulfate (5.5 atom %) at different rates, and to assess the residual fertilizer effect in two no-tillage succession crops (signalgrass and corn). Two maize crops were evaluated, the first in the growing season 2006, the second in 2007, and brachiaria in […]

The quality of no-tillage systems depends on an adequate soil management that promotes soil structure improvements. This is associated to the cropping system adopted. This study investigated the effect of long-term no-tillage systems (18 years) on the structural quality of a sandy-clay to clay Oxisol (Latossolo Vermelho) in the region of Campos Gerais, Paraná, Brazil. Five cropping systems were assessed: wheat-soybean [Wt-So], black oat-maize-wheat-soybean [Ot-Mz-Wt-So], vetch-maize-wheat-soybean [Vt-Mz-Wt-So], ryegrass-maize-ryegrass-soybean [Rg-Mz-Rg-So]; and alfalfa-maize [Alf-Mz]. Soil was sampled from the layers 0-5, 5-10 and […]

Soil resistance to penetration is frequently used as an indicator of soil compaction in management systems and can be directly related to crop growth and yields in general. It is important to use geostatistical methods in the assessment of soil resistance to penetration by considering the data heterogeneity of the area. The purpose of this study was to evaluate the spatial variability of soil penetration resistance (PR) in a Vertisol with mango trees. Data collection was performed in the Project […]

Studies on soil characterization in unexplored regions, besides the generation of data banks for the soil classes of the country, also produce scientific information about soil properties, important for the development of good management practices and sustainable land use. One of the main soil classes in the semiarid region of Pernambuco State, the Regosols, cover about 27 % of the state area, and are used mainly for family agriculture. Due to different geological and climatic aspects Regosols with different chemical, physical […]

One way of classifying water quality is by means of indices, in which a series of parameters analyzed are joined a single value, facilitating the interpretation of extensive lists of variables or indicators, underlying the classification of water quality. The objective of this study was to develop a statistically based index to classify water according to the Irrigation Water Quality Index (IWQI), to evaluate the ionic composition of water for use in irrigation and classify it by its source. For […]

Acid mine drainage (AMD) is a worldwide environmental problem. It is caused by the chemical oxidation process of materials containing sulfide minerals exposed to atmospheric conditions mediated by bacteria. Acidic waters generated in these environments can affect the quality of water bodies. Prevention and remediation methodologies are applied in order to contain AMD. As an alternative for prevention, dry covers have been studied, because remediation usually means very high costs. The objective of this study was to evaluate the effectiveness […]

Gypsum application may enhance the soil quality for plants in terms of soil chemical and physical properties. The objective of this study was to evaluate the effects of gypsum application on the structural quality of a no-tillage Red Latosol. The experiment was initiated in September 2005 in Guarapuava-PR, with gypsum applications of 0; 4; 8; and 12 Mg ha-1 on the soil surface. In November 2009, two soil blocks were sampled from the 0-0.3 m layer for visual evaluation of the soil structure […]

Soil fertilization may be a sustainable strategy for the intensification of grazing, considering that the effects of cattle trampling that are deleterious for the soil physical quality do not affect the productivity and the sustainability of pasture production systems. The purpose of this study was to evaluate the effect of grazing at different intensities of N-fertilized pasture on the soil physical quality and impact on forage and root yield of Panicum maximum cv. IPR-86 Milênio. The experiment was conducted in […]

Increased global demand for food, coupled with the market requirements, not only related to quality, but also to diversity, is leading to an increased use of pesticides in crops. In this context, the search for information and technologies to reduce environmental risks associated with pesticide use plays an important role. Laboratory studies have provided data on the behavior of pesticides in soils, but little is known about the identity and toxicity of the metabolites formed. This study evaluated the behavior […]

The expansion of Brazilian agriculture has led to a heavy dependence on imported fertilizers to ensure the supply of the growing food demand. This fact has contributed to a growing interest in alternative nutrient sources, such as ground silicate rocks. It is necessary, however, to know the potential of nutrient release and changes these materials can cause in soils. The purpose of this study was to characterize six silicate rocks and evaluate their effects on the chemical properties of treated […]