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 […]
Physical quality of an Oxisol under an integrated crop-livestock-forest system in the Brazilian Cerrado
01/Apr/2014
Soil physical quality is an important factor for the sustainability of agricultural systems. Thus, the aim of this study was to evaluate soil physical properties and soil organic carbon in a Typic Acrudox under an integrated crop-livestock-forest system. The experiment was carried out in Mato Grosso do Sul, Brazil. Treatments consisted of seven systems: integrated crop-livestock-forest, with 357 trees ha-1 and pasture height of 30 cm (CLF357-30); integrated crop-livestock-forest with 357 trees ha-1 and pasture height of 45 cm (CLF357-45); […]
Soil uses during the sugarcane fallow period: influence on soil chemical and physical properties and on sugarcane productivity
01/Apr/2014
The planting of diversified crops during the sugarcane fallow period can improve the chemical and physical properties and increase the production potential of the soil for the next sugarcane cycle. The primary purpose of this study was to assess the influence of various soil uses during the sugarcane fallow period on soil chemical and physical properties and productivity after the first sugarcane harvest. The experiment was conducted in two areas located in Jaboticabal, São Paulo State, Brazil (21o 14′ 05” […]
Effect of seed drill with fixed shanks for deep action in soil under no-till
01/Apr/2014
The adoption of no-till in the humid subtropical region of Brazil based on only two precepts of conservation agriculture, soil disturbance restricted to the crop row and crop residue maintained as soil cover, has led to stratification of soil chemical properties in the 0-20 cm soil layer and physical degradation of the subsurface layer (from approximately the 5-20 cm depth), which may make for lower yields during short term droughts. The aim of this study was to evaluate the residual […]
Conditioned latin hypercube method for soil sampling in the presence of environmental covariates for digital soil mapping
01/Apr/2014
Soil sampling is one of the most important stages in soil surveys. However, in conventional soil surveys, sampling schemes have proven to be inadequate for digital soil mapping because they may affect the results obtained and, in addition, they do not allow statistical estimations to be performed. This study attempts to evaluate the conditioned Latin Hypercube Sampling (cLHS) method with four environmental covariates (elevation, slope, curvature and land cover/land use map), in comparison to random sampling, in allocating 100 sample […]
Tensile strength of aggregates and compressibility of a soil built up with cover crops in a coal mining area in Candiota, RS, Brazil
01/Apr/2014
Land reclamation after coal mining is essential for the sustainability of that environment. This study aimed to evaluate the structural quality of a soil built up under different cover crops, taking a soil built up without cover crops and natural soil under native vegetation across from the mining operation as references. It may be concluded that cover crops, especially Tanzania (Panicum maximum), contributed to improvement of the structural quality of the built-up soil, reducing bulk density and increasing macroporosity, total […]
Evaluation of physical quality indices of a soil under a seasonal semideciduous forest
01/Apr/2014
The concept of soil quality is currently the subject of great discussion due to the interaction of soil with the environment (soil-plant-atmosphere) and practices of human intervention. However, concepts of soil quality relate quality to agricultural productivity, but assessment of soil quality in an agronomic context may be different from its assessment in natural areas. The aim of this study was to assess physical quality indices, the S index, soil aeration capacity (ACt/Pt), and water storage capacity (FC/Pt) of the […]
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 […]
The contribution of sediment sources in a rural catchment under no-tillage
01/Apr/2014
Knowledge of the main diffuse sources of sediment production can enhance efficiency in use of public resources invested in management strategies that seek to mitigate sediment transfer to waterways from catchment areas. The aim of the present study was to evaluate the sediment sources in a rural catchment with predominance of annual crops under a no-tillage system and with intense and inappropriate exploitation of natural resources (soil and water) by quantifying the relative contribution of roads and croplands in the […]