Title:	Soil structure evolution under two soil management systems in a clay oxisol from Cerrado region.
Authors:	FREITAS, P. L. de BLANCANEAUX, P. SILVA, F. C. da LIMA, E. M. B. MOREAU, R. FELLER, C. FORTIER, M.
Affiliation:	PEDRO LUIZ DE FREITAS, CNPS; PHILIPPE BLANCANEAUX, ORSTOM; FABIO CESAR DA SILVA, CNPS; EDLA MARIA BEZERRA LIMA, CNPS; ROLAND MOREAU, ORSTOM; CHRISTIAN FELLER, ORSTOM; MICHEL FORTIER, CIRAD.
Date Issued:	1998
Citation:	In: WORLD CONGRESS OF SOIL SCIENCE, 16., 1998, Montpellier. Proceedings [...]. Montpellier: ORSTOM, 1998.
Description:	The sustainability of crop production in oxisols of Cerrado Region depends on the understanding of soil structural evolution processes. Modifications in soil structure were followed for 4 years allowing the comparison of two soil management systems: conventional plowing with heavy disk harrow (CCL), and zero-tillage (PDC). Structural characterization was achieved by morpho-structural analysis, allowing the identification of horizons and homogeneous pedological units (HPU). From samples taken from most representative HPUs it were performed: pH, acidity, CEC, nutrient status, bulk and particle densities, pore size distribution from pF curves, pedo-structural characteristics from soil swelling curves, organic matter status, and micromorphological observations. Morphological differences were identified between surface horizons. Under CCL, the structural state evolved to a compaction, with well developed angular blocky HPUs, high inter-aggregate cohesion and a sufficient macroporal space. Root growth and crop performance, however, were menaced by the lack of pore continuity. In PDC, results have shown an improvement in soil structure, with moderate resistance and inter-aggregate cohesion, and well developed subangular blocky HPUs. Pore space, besides being not different from compacted horizons found in CCL, have a favorable continuity. Significant gains in yields were observed in PDC, showing a better nutrient status. Benefit/cost relationship in PDC has enhanced net income, reflecting the better structural condition. Soil structure evolution studies were important to verify the improvement in soil quality and health under no-till, an alternative soil management system for sustainable crop production in Brazilian Cerrado Region.
Thesagro:	Estrutura do Solo Oxisol Cerrado Manejo do Solo
NAL Thesaurus:	Soil structure Soil management Oxisols
Notes:	Scientific registration n.: 1056. Symposium n.: 2. Presentation: poster.
Type of Material:	Artigo em anais e proceedings
Access:	openAccess
Appears in Collections:	Artigo em anais de congresso (CNPS)