Volume 38, Number 2, 2014
Plant-available soil water capacity: estimation methods and implications
01/Apr/2014
The plant-available water capacity of the soil is defined as the water content between field capacity and wilting point, and has wide practical application in planning the land use. In a representative profile of the Cerrado Oxisol, methods for estimating the wilting point were studied and compared, using a WP4-T psychrometer and Richards chamber for undisturbed and disturbed samples. In addition, the field capacity was estimated by the water content at 6, 10, 33 kPa and by the inflection point […]
Structural quality of polyacrylamide-treated cohesive soils in the coastal tablelands of Pernambuco
01/Apr/2014
Water-soluble polymers are characterized as effective flocculating agents due to their molecular features. Their application to soils with horizons with structural problems, e.g, a cohesive character, contributes to improvements in the physical quality and thus to the agricultural suitability of such soils. The purpose of this study was to evaluate the structural quality of soils with cohesive horizons of coastal tablelands in the State of Pernambuco treated with polyacrylamide (PAM) as chemical soil conditioner. To this end, three horizons (one […]
Methane fluxes from waterlogged and drained Histosols of highland areas
01/Apr/2014
Soil can be either source or sink of methane (CH4), depending on the balance between methanogenesis and methanotrophy, which are determined by pedological, climatic and management factors. The objective of this study was to assess the impact of drainage of a highland Haplic Histosol on CH4 fluxes. Field research was carried out in Ponta Grossa (Paraná, Brazil) based on the measurement of CH4 fluxes by the static chamber method in natural and drained Histosol, over one year (17 sampling events). […]
Long-term effects of the application of gypsum and lime in a no-till system
01/Apr/2014
The effects of lime and gypsum are widely discussed in the literature, but their magnitude in relation to effects in the soil profile is dependent on the time since application of these inputs. Thus, the aim of this study is to evaluate the effect of long-term application of gypsum and lime on chemical properties of a soil in crop rotation in a no-till system. The experiment was carried out in Jaguariaíva, Paraná state, Brazil, in a sandy loam Latossolo Vermelho-Amarelo […]
Variability of soil fertility properties in areas planted to sugarcane in the State of Goias, Brazil
01/Apr/2014
Soil sampling should provide an accurate representation of a given area so that recommendations for amendments of soil acidity, fertilization and soil conservation may be drafted to increase yield and improve the use of inputs. The aim of this study was to evaluate the variability of soil fertility properties of Oxisols in areas planted to sugarcane in the State of Goias, Brazil. Two areas of approximately 8,100 m2 each were selected, representing two fields of the Goiasa sugarcane mill in […]
Partial substitution of soluble phosphate by rock phosphate in the planting of Eucalyptus benthamii and Eucalyptus dunnii in southern Brazil
01/Apr/2014
Phosphorus fertilization is important for the initial growth of eucalyptus. Soluble phosphate (SP) sources are commonly used for this purpose because they offer fast dissolution in the soil, but these sources have higher costs than rock phosphate (RP), which has lower solubility. The aim of this study was to evaluate the use of RP as a partial substitute for SP for the initial supply of P to Eucalyptus benthamii and E. dunnii. Two field experiments were carried out (one with […]
Production and quality of roses as affected by boron fertilization
01/Apr/2014
Many studies have shown the effects of boron (B) application on various crops; however, results on roses are scarce. The aim of this experiment was to evaluate the effects of B on the production and quality of roses (Rosa hybrida Shiny Terrazza®) under controlled conditions. Treatments consisted of five rates of B (0, 1, 4, 8 and 16 mg kg-1) applied in the substrate in a randomized block design with five replicates. We evaluated the cycle; number of flowers per […]
Fertilization of ornamental plants: requirement-supply method
01/Apr/2014
The recommendation of a fertilizer dose for a crop depends on nutrient gain-loss balance in the agricultural system (Restitution Law). At the Federal University of Viçosa (UFV), this balance has been modeled for liming and fertilizer recommendations for eucalyptus (NUTRICALC), pineapple, cotton, rice, banana, coffee, sugarcane, coconut, orange, melon, maize, pastures, soybean, tomato (FERTICALC), and for teak (FERTI – UFV). Fertilization and nutrition of tropical ornamental plants is based on the knowledge of growers and fertilizer manufacturers. This study was […]
Available content, surface runoff and leaching of phosphorus forms in a typic hapludalf treated with organic and mineral nutrient sources
01/Apr/2014
The application of animal manure to soil can increase phosphorus availability to plants and enhance transfer of the nutrient solution drained from the soil surface or leached into the soil profile. The aim of this study was to evaluate the effect of successive applications of organic and mineral nutrient sources on the available content, surface runoff and leaching of P forms in a Typic Hapludalf in no-tillage systems. Experiment 1 was set up in 2004 in the experimental area of […]
Estimation of soil water infiltration at the catchment scale
01/Apr/2014
The spatial variability of soil characteristics makes the estimation of water infiltration highly dependent on the scale of analysis. Many studies require information on the dynamics of infiltration to describe the dynamics of other processes associated with water, sediment and solutes. This study aims to use two methodological strategies to estimate water infiltration at the catchment scale. The parameters of two infiltration models were fitted to a data set collected over two years of monitoring (77 rainfall-runoff events) occurring under […]