Volume 36, Number 3, 2012

Landfill gas emissions are one of the main sources of anthropogenic methane (CH4), a major greenhouse gas. In this paper, an economically attractive alternative to minimize greenhouse gas emissions from municipal solid waste landfills was sought. This alternative consists in special biofilters as landfill covers with oxidative capacity in the presence of CH4. To improve the quality/cost ratio of the project, compost was chosen as one of the cover substrates and soil (Typic red yellow-silt-clay Podzolic) as the other. The […]

Ammonia volatilization and nitrification/denitrification are the two major N loss mechanisms in rice production. If N fertilizer is not managed appropriately, N recovery by rice plants can be low. The purpose of this study was to quantify ammonia volatilization in flooded soils influenced by the urea application method. A greenhouse study was conducted to quantify the potential of N loss via ammonia volatilization in flooded soils influenced by the urea application method. Two experiments were carried out, one in Mississippi, […]

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 […]

The land use and land use and management changes are among the main determinants of the stocks of soil organic carbon (SOC). The spatially explicit dynamic modeling is a technique that has been successfully used in evaluations of regional SOC stocks changes. Thus, this study aimed to use the Century 4.0 model associated with geoprocessing and remote sensing techniques to evaluate the effects of agricultural use and soil management changes on dynamics of soil organic carbon (SOC) on farms in […]

The intensive use of soils in the Cerrado biome has caused modifications in soil properties, as well as in the performance and quality of organic matter. The Cerrado of Piauí has been exploited without due concern for the preservation of natural resources, where production systems are characterized by intensive land use. The objective of this research was to evaluate the effect of the agricultural use in altering the biological properties and dynamics of organic matter of Yellow Oxisols cultivated with […]

The relationship between yield and nutrient concentration in plants is the basis used as a diagnostic criterion for foliar analysis. There are several diagnostic methods that use the analysis of plant tissues where they play a key role in the definition and interpretation of plant nutritional status. The average nutrient concentration changes during the crop cycle, which is important for defining the time of leaf sampling. The purpose of this study was to determine the best sampling time of banana […]

Yield and conservation of onion bulbs are influenced by nitrogen (N) availability in the soil, which is required in large amounts. This study aimed to evaluate the effect of N application rates and splitting on the plant nutritional status, yield and conservation of onion bulbs after harvest. Three field experiments were carried out in Southern Brazilian Haplumbrepts. Treatments consisted of a factorial combination (4 x 3) involving four N rates (0, 50, 100, and 200 kg ha-1) and three times of sidedressing (only 45, […]

The species Salix x rubens is being grown on the Southern Plateau of Santa Catarina since the 1940s, but so far the soil fertility requirements of the crop have not been assessed. This study is the first to evaluate the production profile of willow plantations in this region, based on the modified method of Summer & Farina (1986), for the recommendation of fertility levels for willow. By this method, based on the law of Minimum and of Maximum for willow production for […]

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 […]

Continuous agricultural production in the Amazon region requires correction of soil acidity and understanding of the long-term interactions of liming with chemical soil properties. The objective of this study was to evaluate the immediate and residual effects of lime on annual crop production and soil properties of medium-textured Oxisols in the Brazilian Amazon. Field experiments were conducted at two locations in the Northeast of Pará from 2003 to 2008, one in the county of Terra Alta and the other in […]