Distribution and uncertainty of acidity of an oxisol under coffee cultivation
01/Aug/2009
With the development of agriculture, the use of new tools for the evaluation of the properties related to plant yields have become essential to improve the management of agricultural systems. The purpose of this study was to use a fuzzy model to investigate, based on soil chemical properties, the propagation of uncertainty of the acidity of a humic Red-Yellow Latosol (Oxisol) under Arabic coffee plantation. The soil was sampled at a depth of 0 – 0.2 m, in a grid, […]
Crop sequences in no-tillage system: effects on soil fertility and soybean, maize and rice yield
01/Apr/2009
Decomposing crop residues in no-tillage system can alter soil chemical properties, which may consequently influence the productivity of succession crops. The objective of this study was to evaluate soil chemical properties and soybean, maize and rice yield, grown in the summer, after winter crops in a no-tillage system. The experiment was carried out in Jaboticabal, SP, Brazil (21 ° 15 ‘ 22 ” S; 48 ° 18 ‘ 58 ” W) on a Red Latosol (Oxisol), in a completely randomized block design, in strip plots with three replications. The treatments consisted of […]
Soybean yield variabillity regarding physical properties of a typic acrustox under no-tillage
01/Apr/2009
Nowadays no-tillage soybean is widely used in crop-livestock farming systems in Brazil. The yield of no-tillage soybean was analysed in the county of Selvíria (latitudes from 20 ° 18 ‘ 05 ” S and 20 ° 18 ‘ 28 ” S and the longitudes de 52 ° 39 ‘ 02 ” W and 52 ° 40 ‘ 28 ” W (Mato Grosso do Sul State – Brazil), in the 2006/07 growing season, as affected by some physical properties of a local Typic Acrustox. The objective was to determine the soil property that could best explain the variability in the agricultural productivity. For this purpose, […]
Soil chemical properties and grapevine yield affected by cover crop management in Serra Gaucha, Southern Brazil
01/Feb/2009
Soil management can have effects on nutrient availability and fruit yield. The objective of this study was to evaluate the effect of phytomass management forms of different cover crop species on soil chemical properties related to organic matter, nutrient availability, and on grapevine yields. The experiment was carried out in Embrapa Uva e Vinho, in Bento Gonçalves, RS, in Southern Brazil, on a Haplic Cambissol, in a vineyard established in 1989, using White and Rose Niagara grape in a horizontal […]
Bearing capacity and compressibility of argisol (paleudult) as affected by traffic and winter cover crops
01/Dec/2008
One of the most effective practices in preventing soil compaction is to apply stresses below the bearing capacity of the soil, often estimated by the pre-compression stress (σp). To evaluate the effects of cover crops and tractor traffic on σp and compression index (CI), a field experiment was initiated in 2002 on sandy clay loam Paleudult, in Southern Brazil (Rio Grande do Sul State). Treatments under no-tillage involved winter fallow and two winter cover crops (black oats and black oats […]
Linear and spatial correlation between the soil penetration resistance and irrigated bean yield
01/Oct/2008
Soil penetration resistance exercises major influence on crop development, root growth and crop productivity, which is inversely proportional to that soil attribute. In this way, the analysis of spatial variability of soil penetration resistance and crop yield based on geostatistics can indicate alternative management practices, not only to reduce the effects of soil variability on crop yield, but also to improve the estimated crop response under certain management practices. This study aimed to correlate soil penetration resistance (RP) and spatial […]
Physiological responses of orange trees to permanent groundcover vegetation types
01/Jun/2008
The presence of a groundcover in-between tree rows in orange orchards can affect the water uptake and physiology of the orange trees. The objective of this study was to characterize the relationships between the physiological variables of orange leaf and soil water content in a Paleudults in groundcover management systems with bahiagrass (Paspalum notatum), leguminous perennial peanut (Arachis pintoi) and spontaneous vegetation. The study was performed in in an experimental “Pêra” orange orchard established in 1993 in Alto Paraná, northwestern […]
Linear and spatial correlation between common bean yield and porosity of a Red Latosol in Selvíria (MS), Brazil
01/Apr/2008
Soil porosity influences plant development since root growth and crop yield are determined by the root depth. The objective of this study was to investigate the linear and spatial variability and correlations between common bean yield and soil porosity. The bean grain yield of the irrigated cultivar Carioca IAC was analyzed in the growing season 2004/2005, in Selviria-MS, as well as macroporosity (MA), microporosity (MI) and total porosity (TP), in a Dystroferric Red Latosol, at four depths: 1 (0.0-0.10 m), 2 (0.10-0.20 m), 3 (0.20-0.30 m) […]
Inter-relationships between physical properties and the coefficients of soil water retention curve in an oxisol under different soil use
01/Apr/2008
Practices of soil use and management are based on the physical and hydric soil behavior. Our objective was to evaluate the inter-relationships between physical properties and coefficients of soil water retention curves in an Oxisol under different soil use systems. In 2004, three contiguous areas were selected, covered for over 20 years by forest (native), Brachiaria decumbens (fallow) and annual crops (cultivation). Twenty-five undisturbed soil samples were collected at a depth of 0-0.15 m to determine the soil water retention curves. […]
Fruit yields of ‘Pêra’ orange under different soil tillage and interrow management systems
01/Feb/2008
The conventional soil tillage used in the implantation of citrus orchards is based on the removal of the plant residues and soil tilling in the entire area, and the management of orchards on the elimination of any plant residues from the interrows. This has led to erosion and reduced soil fertility, with negative effects on the trees and the environment. The objective of this study was to evaluate soil management systems that decrease soil erosion and improve the fertility status […]