Soil Compressibility under Irrigated Perennial and Annual Crops in a Semi-Arid Environment
07/Jul/2017
ABSTRACT In irrigated soils, a continuous state of high moisture reduces resistance of the soil to applied external forces, favouring compaction. The aim of this study was to evaluate the susceptibility to compaction of developed calcareous soils in irrigated annual and perennial cropping systems of the Apodi Plateau, located in the Brazilian semi-arid region. Four areas of irrigated crops were evaluated: banana after two (B2) and 15 (B15) years cultivation, pasture (P), and a corn and beans succession (MB), as […]
Chemical Properties in Macroaggregates of a Humic Dystrudept Cultivated with Onion under No-Till and Conventional Tillage Systems
12/Jun/2017
ABSTRACT Nutrients present in soil aggregates are essential for maintaining the productive capacity of agroecosystems and environmental quality. The aim of this study was to evaluate the chemical properties of macroaggregates of a Humic Dystrudept cultivated with onions under a no-till vegetable system (NTVS) compared to the conventional tillage system (CTS) and a forest area in Ituporanga, SC, Brazil. The treatments consisted of the following single and mixed cover crops with onion under the NTVS: spontaneous vegetation, 100 % black […]
Modeling Root Growth, Crop Growth and N Uptake of Winter Wheat Based on SWMS_2D: Model and Validation
12/Jun/2017
ABSTRACT Simulations for root growth, crop growth, and N uptake in agro-hydrological models are of significant concern to researchers. SWMS_2D is one of the most widely used physical hydrologically related models. This model solves equations that govern soil-water movement by the finite element method, and has a public access source code. Incorporating key agricultural components into the SWMS_2D model is of practical importance, especially for modeling some critical cereal crops such as winter wheat. We added root growth, crop growth, […]
Effect of Harvest Time and Nitrogen Doses on Cassava Root Yield and Quality
12/Jun/2017
ABSTRACT Nitrogen is considered the most limiting nutrient for cassava, and N availability can influence the crop cycle, including earlier harvest. The aim of this study was to study the effect of harvest time on the production components of cassava, “Aciolina” cultivar, at different rates of N fertiliser. The experiment was carried out in an area newly incorporated into the productive system in a savannah ecosystem in the northern Amazon. A randomised block experimental design was used in a split […]
Organic Carbon and Physical Properties in Sandy Soil after Conversion from Degraded Pasture to Eucalyptus in the Brazilian Cerrado
12/Jun/2017
ABSTRACT Soil is currently seen as the most relevant carbon sink and the most effective carbon stabilizer. In contrast, agriculture is the second largest C emitter, after burning of fossil fuels. This organic carbon (OC) introduced into the soil, mainly via organic matter (OM), is essential for several soil properties and plays an extremely important role in sandy soils. The objective of this study was to describe the changes in the amounts and pools of OC and the influence thereof […]
Mitigation of the Gradient of Chemical Properties in the Rooting Zone of Dystrophic Oxisols by Gypsum and Lime Inputs under a No-Till System
12/Jun/2017
ABSTRACT Improvement of soil chemical properties in dystrophic Oxisols managed under long-term no-tillage system (NTS) with surface broadcast lime has been, frequently, restricted to a shallow topsoil layer. As a consequence, a sharply-defined chemical quality gradient is created, with deterioration from the surface towards deeper layers in Oxisols in southern Brazil. The aim of this study was to assess the temporal effects of gypsum, applied alone or in combination with lime, on Ca2+ content and Al3+ saturation in the rooting […]
Nutrient Uptake and Removal by Potato Cultivars as Affected by Phosphate Fertilization of Soils with Different Levels of Phosphorus Availability
12/Jun/2017
ABSTRACT Studies in the past decades have focused on how tuber yield of potato grown on different types of soil is affected by phosphate fertilizer rates. However, little is known about the effects of phosphorus availability in the soil and of phosphate fertilization on nutrient uptake and removal by the main potato cultivars currently grown in Brazil. Thus, in this study we investigated the influence of P fertilization rates on dry matter (DM) yield and nutrient uptake and removal in […]
Effects of Soil Management Practices on Water Erosion under Natural Rainfall Conditions on a Humic Dystrudept
12/Jun/2017
ABSTRACT Water erosion is the main cause of soil degradation and is influenced by rainfall, soil, topography, land use, soil cover and management, and conservation practices. The objective of this study was to quantify water erosion in a Humic Dystrudept in two experiments. In experiment I, treatments consisted of different rates of fertilizer applied to the soil surface under no-tillage conditions. In experiment II, treatments consisted of a no-tillage in natural rangeland, burned natural rangeland and natural rangeland. Forage turnip, […]
Analysis of Potential for Linear Erosion in the Cerrado Biome Using Morphopedology
12/Jun/2017
ABSTRACT The Cerrado is a vegetation complex with a wide variety of phytophysiognomies, and sustainable management is essential for maintaining biodiversity. Morphopedology is a tool that can assist in developing plans for control of soil and land use, especially in evaluating the potential of soil erosion processes. This technique allows landscape units considered “homogeneous” to be distinguished, as a result of interaction between physiographic conditions. The aim of this study was to evaluate potential for erosion in São Miguel do […]
Calcium and Magnesium Released from Residues in an Integrated Crop-Livestock System under Different Grazing Intensities
01/Apr/2017
ABSTRACT Under integrated crop-livestock production systems (ICLS), plant and animal residues are important nutrient stocks for plant growth. Grazing management, by affecting the numbers of both plants and animals and the quality of residues, will influence nutrient release rates. The objective of this study was to evaluate the impact of grazing intensity on Ca and Mg release from pasture, dung, and soybean residues in a long-term no-till integrated soybean-cattle system. The experiment was established in May 2001 in a Latossolo […]