83 results

Spatial and temporal variability of crop yield and some Rhodic Hapludox properties under no-tillage

Osvaldo Guedes Filho, Sidney Rosa Vieira, Márcio Koiti Chiba, César Hideo Nagumo, Sônia Carmela Falci Dechen

01/Feb/2010

Soil properties are closely related with crop production and spite of the measures implemented, spatial variation has been repeatedly observed and described. Identifying and describing spatial variations of soil properties and their effects on crop yield can be a powerful decision-making tool in specific land management systems. The objective of this research was to characterize the spatial and temporal variations in crop yield and chemical and physical properties of a Rhodic Hapludox soil under no-tillage. The studied area of 3.42 […]

Movement of a solute applied in two concentrations to an unsaturated soil via a disk permeameter

E. Borges, P. L. Libardi

01/Jun/2002

Groundwater pollution is one of the main factors justifying the study of soil solute movement and the processes of soil solute interaction. A deeper penetration than the expected of the chemicals applied to the soil surface, together with laboratory observations of the decrease of the amount of solutes in the solution passing through the soil, led researchers to consider the soil water (or solution) as having two phases: a mobile phase, θm, and an immobile phase, θim. In this paper, […]

Factors controlling compressibility of a paleudalf and a haplortox soil. I- initial state of compactness

V. R. Silva, D. J. Reinert, J. M. Reichert, J. M. Soares

01/Mar/2002

Knowing the susceptibility of a soil to compaction is important to adjust soil management, tillage practices, and traffic to cause minimal detrimental effects on soil properties. The objective of this study was to determine the preconsolidation pressure (σ’p) and the compression index (Cc) at two depths of two soils under no-tillage and conventional tillage, including a wide variation of the state of compaction. Undisturbed soil samples were collected with rings (5.4cm wide and 2.0cm high), at 0 to 2 and […]

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