3 results

Soil chemical and microbial properties in vineyards under organic and conventional management in southern Brazil

Higo Forlan Amaral, José Ozinaldo Alves Sena, Kátia Regina Freitas Schwan-Estrada, Elcio Libório Balota, Diva Souza Andrade

01/Oct/2011

Organic cropping systems with input of fresh organic matter can modify the physical and chemical properties of soils and consequently affect their biological composition. The purpose of this study was to determine the effects of juice grape (Vitis labrusca L.) management on the soil chemical and microbial properties of a sandy-textured Oxisol. In October 2006, soil was sampled from two vineyard experiments set up in 2000, and from a neighboring forest area. The following treatments were evaluated in a 2 […]

Changes in chemical attributes of sandy soil under no-tillage

D. S. Rheinheimer, J. Kaminski, G. C. Lupatini, E. J. S. Santos

01/Dec/1998

No-tillage soil management does not permit incorporation of crop residues and requires surface application of fertilizers and corrective agents, thereby affecting nutrient availability and distribution. This study was carried out to evaluate the chemical changes in no-tillage system compared to conventional tillage and native grass field. Samples from a sandy/clay Red-Yellow Podzolic (Typic Hapludalf), taken at 0-5, 5-10, 10-20 and 20-40 cm depth, were used to determine zero point of salt effect (ZPSE), humic substances, permanent charge, soil pH, exchangeable […]

Sampling strategies for tropical forest nutrient cycling studies: a case study in São Paulo, Brazil

G. Sparovek, O. A. Camargo

01/Dec/1997

The precise sampling of soil, biological or micro climatic attributes in tropical forests, which are characterized by a high diversity of species and complex spatial variability, is a difficult task. We found few basic studies to guide sampling procedures. The objective of this study was to define a sampling strategy and data analysis for some parameters frequently used in nutrient cycling studies, i. e., litter amount, total nutrient amounts in litter and its composition (Ca, Mg, Κ, Ν and P), […]