Indicadores químicos de qualidade da matéria orgânica de solo da sub-bacia do Rio das Mortes sob manejos diferenciais de cafeeiro

Abstract

IndIcadores químIcos de qualIdade da matérIa orgânIca de solo da sub-bacIa do rIo das mortes sob manejos dIferencIaIs de cafeeIro antônio claret oliveira júnior* Instituto Nacional de Colonização e Reforma Agrária, Av. Afonso Pena, 2403, 79002-073 Campo Grande -MS, Brasil carlos alberto silva, nilton curi e luiz roberto guimarães guilherme Departamento de Ciência do Solo, Universidade Federal de Lavras, CP 3037, 37200-000 Lavras -MG, Brasil otacílio josé Passos rangel Escola Agrotécnica Federal de Alegre, CP 47, 29500-000 Alegre-ES, BrasilRecebido em 3/1/08; aceito em 14/5/08; publicado na web em 22/9/08 CHEMICAL INDICATORS OF THE QUALITY OF ORGANIC MATTER OF SOIL FROM THE RIO DAS MORTES WATERSHED UNDER DIFFERENT COFFEE PLANT MANAGEMENTS. This work evaluated the chemical quality of organic matter (OM) of a Brazilian Oxisol cultivated with coffee plants, under organic and conventional managements. Total organic C (TOC), light fraction C (LF-C) and C in humic (HA-C) and fulvic (FA-C) acids fractions was measured. Amongst the evaluated indexes, TOC and LF-C discriminated better OM attributes as a function of management. The stratification ratio (TOC 5-10cm /TOC 10-20cm ) did not show differences between the systems studied. The organic system can contribute to the sustainability of coffee plantations in Brazil, because it maintains the chemical attributes of OM closer to the indexes verified under forest conditions.

MACRO simulator (version 5.0) for predicting atrazine herbicide behavior in brazilian latosols

“…In a large part of those counties, farming stands out as an important income source (OLIVEIRA JÚNIOR et al, 2008) and the use of atrazine has been mainly associated with the corn crop on Latosols (Oxisols). As in other areas of Brazil where this product is applied, studies on the occurrence of residues in soils are rare.…”

Oxidizable fractions of soil organic carbon in Caatinga forest submitted to different forest managements

“…Among the soil chemical attributes, soil organic carbon (SOC) has been frequently used in assessing the conservation status and sustainability of forest ecosystems, since it exerts an influence on practically all soil processes from aggregation to nutrient supply to the plants (ZINN et al, 2002). However, minor changes in SOC may not Batista et al be detected in the short term (CHAN et al, 2001;OLIVEIRA JÚNIOR et al, 2008).…”

“…Among the soil chemical attributes, soil organic carbon (SOC) has been frequently used in assessing the conservation status and sustainability of forest ecosystems, since it exerts an influence on practically all soil processes from aggregation to nutrient supply to the plants (ZINN et al, 2002). However, minor changes in SOC may not Batista et al be detected in the short term (CHAN et al, 2001;OLIVEIRA JÚNIOR et al, 2008). For this reason, studying the distribution of SOC in labile or stable fractions of soil organic matter (SOM) has been adopted which expresses differences in its storage time in the soil (BAYER et al, 2004), and shows changes in organic C quality before differences even occur in their total content (XAVIER et al, 2006;BARRETO et al, 2011).…”

“…However, minor changes in SOC may not Batista et al be detected in the short term (CHAN et al, 2001;OLIVEIRA JÚNIOR et al, 2008). For this reason, studying the distribution of SOC in labile or stable fractions of soil organic matter (SOM) has been adopted which expresses differences in its storage time in the soil (BAYER et al, 2004), and shows changes in organic C quality before differences even occur in their total content (XAVIER et al, 2006;BARRETO et al, 2011).…”

“…The first two fractions are considered to be of greater lability; and therefore, are usually more responsive to soil changes. The latter two fractions are less labile and are more related to compounds possessing higher chemical stability and molar mass (RANGEL et al, 2008).…”