ABSTRACT Modern maize, wheat, and soybean cultivars are usually characterized by a short cycle, high shoot-root ratio, and high responsiveness to nutrient input. Continuous no-tillage management (NTS) frequently leads to a steep gradient in soil chemical quality with depth, thus decreasing yield under conditions of acid subsoil and water stress. This study aimed to evaluate the effect of gypsum, applied separately or in combination with lime, on the yield of cultivars used in the state of Rio Grande do Sul, […]

Abstract Plant health and nutrition are strongly influenced by the availability of water. The objective of this study was to evaluate the different patterns of initial growth and nutritional efficiency of ten drought-stressed Eucalyptus clones. Water stress conditions were induced by osmotic stress, by gradual addition of polyethylene glycol 6000 over a 20-day period. Drought stress significantly reduced the dry matter of leaves, roots, and the whole plant as well as the nutritional efficiency of most clones. Clone PL040 was […]

ABSTRACT High nitrogen (N) losses by ammonia (NH3) volatilization from urea can compromise nitrogen fertilization efficiency and corn yield. The purpose of this study was to assess the effects of irrigation management and the addition of the urease inhibitor N-(n-butyl)thiophosphoric triamide (NBPT) on NH3-N losses from urea and on corn yield. To this end, two experiments were carried out in the 2011/12 crop season on a sandy clay loam Acrisol in the Central Basin region of Rio Grande do Sul, […]

ABSTRACT High winter cereal yields depend on an adequate supply of nitrogen (N). We developed a system for indicating N rates for wheat and barley in the South-Central region of the state of Paraná, Brazil, using results of 72 field experiments conducted from 2007 to 2012. The N rates recommended for winter cereals were estimated to supply the amounts of N fertilizer needed to obtain increasing yields (5.5 Mg ha-1) of crops grown after soybean and corn on soils with […]

ABSTRACT Nitrogen derived from cover crop residues may contribute to the nutrition of onion grown under minimum tillage (MT) and cultivated in rotation. The aim of this study was to evaluate the N transferred from different cover crop residues to the onion crop cultivated under MT in southern Brazil. In June 2014, oilseed radish, black oat, and oilseed radish + black oat residues labeled with 15N were deposited on the soil surface before transplanting onions. During the growth season and […]

ABSTRACT Water erosion, the main factor in soil degradation, is strongly influenced by soil cover and management. The objective of this study was to determine soil and water losses under natural rainfall conditions from 1993 to 2012 in the southern Santa Catarina Plateau, Brazil, in 3.5 × 22.1 m plots with crops in rotation to study the following management treatments: conventional tillage (CT), minimum tillage (MT), and no-tillage (NT), and a treatment with bare soil (BS). The soil cover remaining […]

ABSTRACT The intensive nature of soil use in vegetable production areas has led to a marked decrease in soil quality. The objective of this study was to evaluate the effects of adoption of soil management systems on vegetable production with regards to the chemical properties of a Rhodic Ferralsol after five years and to evaluate the use of the Principal Component Analysis (PCA) statistical tool in discriminating the different treatments. The experiment was conducted under field conditions in central Brazil […]

Abstract Erosion generates large amounts of sediment, which may be deposited at the site of origin, on the slope of a hill, or along waterways. The transportability of each type of sediment by runoff and its potential for subsequent deposition largely depends on its morphological features and particle size distribution. The aim of this study is to describe and characterize the morphology and micromorphology of sediments deposited in a reforested area and to understand the dynamics of the transport process. […]

ABSTRACT Soil structure plays an important role in water retention, infiltration capacity, porosity, and penetration resistance. The aim of this study was to evaluate the unsaturated hydraulic conductivity and physical properties of Oxisol soils (bulk density and macro-, micro-, and total porosity) in the structures identified using the profil cultural method in areas under two different management practices (perennial pasture and sugarcane). Three pits were dug in each plot to find out how homogeneous morphological structural units (HMSU) were organized […]

ABSTRACT Many Amazonian farmers use the slash-and-burn method rather than fertilization for crop production. The aim of the present study was to evaluate changes in the morphological, physical, and chemical properties of naturally fertile Inceptisols after conversion from native forest to different uses in southern Amazonia, Brazil. Land covered by dense native forest (NF) was split into four areas of 1.0 ha each. Three areas were slashed and burned and then cultivated for 11 years with coffee (CO), secondary forest […]