Use of the swat model for hydro-sedimentologic simulation in a small rural watershed
01/Apr/2012
Mathematical models have great potential to support land use planning, with the goal of improving water and land quality. Before using a model, however, the model must demonstrate that it can correctly simulate the hydrological and erosive processes of a given site. The SWAT model (Soil and Water Assessment Tool) was developed in the United States to evaluate the effects of conservation agriculture on hydrological processes and water quality at the watershed scale. This model was initially proposed for use […]
Assessment of Efficiency and Adequacy of Retention Terraces
01/Apr/2012
Due to losses caused by water erosion, the development of techniques that increase the efficiency of soil conservation practices is fundamental. Terracing of agricultural lands is an important conservation practice. Bearing in mind that improperly built terraces may negatively affect the landscape, the purpose of this work was to evaluate the efficiency as well as the adequacy of retention terraces. Assessments were performed in four terraces implanted in different states, all located in the mideastern region of the state of […]
Runoff and sediment transport in a degraded area
01/Feb/2012
Gully erosion occurs by the combined action of splash, sheetwash and rill-wash (interrill and rill erosion). These erosion processes have a great capacity for both sediment production and sediment transport. The objectives of this experiment were to evaluate hydrological and sediment transport in a degraded area, severely dissected by gullies; to assess the hydraulic flow characteristics and their aggregate transport capacity; and to measure the initial splash erosion rate. In the study area in Guarapuava, State of Paraná, Brazil (lat […]
Soil erosion resistance in ravines in a sandy clay loam oxisol
01/Dec/2011
Ravines represent one of the formations resulting from water erosion, with concentrated surface water flow down hillsides of degraded areas, yet without subsurface water flow. The objective of this study was to evaluate hydraulic flow conditions in ravines as well as to determine soil erosion resistance parameters: soil erodibility (Kr) and critical shear stress (τc) on the ravine surfaces, as well as to determine soil erodibility at several depths of degraded hillsides along the coastline of the state of Pernambuco. […]
Soil and water loss and water infiltration in red latosol under different management systems
01/Oct/2011
The soil management systems change the microrelief and the crop residue cover, influencing the soil and water losses. In this study evaluated the soil and water losses and estimated the water final infiltration rate in different soil managements models under simulated rainfall. Crop residues were evaluated in the field after harvest of soybean (Glycine max L. Merrill). Three soil managements systems were studied: no-tillage, disk harrow and chisel plow associated with three levels of dry soybean residue: 0; 2; and […]
Environmental zoning applied to soil and water conservation
01/Oct/2011
The environmental zoning for soil and water conservation provides useful information about land use and management. Thus, this study proposes (i) an environmental zoning, based on the combination of Universal Soil Loss Equation (USLE), soil loss tolerance (T) estimates adapted to Brazilian soils and environmental legislation; and (ii) qualitative-quantitative monitoring of water resources using Total Maximum Daily Load curves (TMDLs). The study area was the Ribeirão Salobra Basin (Terenos, MS, Brazil), located in the transition between the biomes Cerrado and […]
Liquid dairy manure in no-till: carbon and nitrogen loss by runoff
01/Oct/2011
The use of manure in agricultural system is a possibility to dispose of the waste generated in animal production, but improper use can cause environmental problems. The general objective of this study was to evaluate carbon and nitrogen concentrations and losses in runoff in four doses of liquid dairy manure (0, 60, 120, 180 m3 ha-1 yr-1) applied to a silt clay loam Oxisol with 13 % slope, in no-till with soybean, oat, corn, and wheat in crop rotation. The […]
Ion mobility in a no-tillage soil subjected to mineral and organic fertilization
01/Aug/2011
The retention in soil profiles of surface-applied mineral elements is crucial to maintain the water quality and reduce environmental and economic damages. This study evaluated: the mobility of potassium, calcium and magnesium, aluminum and organic matter contents and changes in pH in an Eutroferric Red Latosol under no-tillage, and the chemical oxygen demand (COD) of percolated water. Mobility was assessed in an undisturbed soil column with preserved structure and treated with mineral (100 kg ha-1) and organic (150 m3 ha-1) […]
Physical, chemical and biological soil properties of gully environments in Lavras – MG
01/Apr/2011
In the southern region of Minas Gerais large areas are affected by gully erosion. The evaluation of soil properties in these environments is extremely important, in view of their sensitivity to changes in soil quality. The objectives of this study were to evaluate physical, chemical and biological soil properties and their relationship with vegetation in the gullies. The study examined three gullies, one on an Inceptisol and two on Oxisols- LVA1 and LVA2, in Lavras, Minas Gerais (SE Brazil). Different […]
Hydraulic characteristics of rill erosion in a semi-arid cambissolo in Brazil
01/Aug/2010
Rill erosion begins with the concentration of surface runoff on depressions of soil surface, evolving into the formation of channels or ravine, increasing soil degradation by water erosion. The objectives of this study were to evaluate the hydraulic conditions of the water flow in rills and characterize the water flow regime, and to measure the induced changes in the geometry of the preestablished rills. An experiment was conducted in which outflows of 17.5; 47.0; 60.0; 77.0 and 110.0 L min-1 were applied […]