Frações Da Materia Orgânica, Indice De Manejo Do Carbono E Atributos Físicos De Um Latossolo Vermelho Sob Diferentes Sistemas De Uso

Abstract

Resumo -O presente estudo teve como objetivo analisar as frações da matéria orgânica, o índice de manejo do carbono e os atributos físicos de um Latossolo Vermelho sob diferentes sistemas de uso. Quatro áreas distintas de uso do solo foram avaliadas: Lavoura de culturas anuais sob sistema plantio direto há mais de 5 anos (LAV-PD); Pastagem com grama estrela (PAST); Plantio florestal de eucaliptos com 10 anos de idade (EUC); Floresta Ombrófila Mista em estagio médio de regeneração (MATA). Amostras de solo foram coletadas nas camadas de 0,00-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,40 m para a determinação do teor de carbono orgânico total (COT), do carbono orgânico particulado (COP), do carbono orgânico associado aos minerais (CAM), do diâmetro médio geométrico de agregados (DMG), da densidade do solo (Ds), da macroporosidade (Ma), da microporosidade (Mi) e da porosidade total (Pt). O estudo mostrou a importância de se realizar avaliações quali-quantitativas do teor de carbono do solo (COT, COP e CAM), no intuito de se avaliar de uma forma mais precisa a contribuição dos sistemas de uso sobre a dinâmica do carbono no ambiente e nos atributos físicos do solo. O tratamento MATA mostrou-se ser o sistema mais equilibrado, considerando todas as camadas de solo avaliadas, pois apresentou a maior estabilidade dos agregados, menor Ds e maior percentual de Pt e Ma em relação aos demais tratamentos.Palavras chave -carbono orgânico total, carbono orgânico associado aos minerais, carbono orgânico particulado, agregação, densidade do solo, macroporosidade. Abstract -The present study aimed to analyze fractions of organic matter, carbon management index and the physical attributes of a Red Latossol under different use systems. Four distinct areas of land use had been selected: No-tillage annual crops 5 years old; Area with pasture ; forest area with eucalyptus plantation 10 years old; MixedRain Forest in average stage of regeneration. Soil samples were collected in layers of 0.00-0.05, 0.05-0.10, 0.10-0.20 and 0.20-0.40 m for determination of total organic carbon, particulate organic carbon, organic carbon associated with minerals, the geometric mean diameter of aggregates, bulk density, the macroporosity, the microporosity and total porosity and . The study showed the importance of conducting evaluations quali-quantitative soil carbon content, in order to assess more precisely the contribution of systems for use on the carbon dynamics in the environment and in the physical attributes of the soil. The treatmentForest proved to be the most balanced, considering all the layers of soil are evaluated, as presented greater stability of aggregates, lower bulk density and higher percentage of total porosity and macroporosity compared to other treatments.

Structural Quality Indicators in Compacted Oxisols Grown With Corn

“…This pattern is due to the higher contribution of plant material in the NF, providing enhance in the level of OM and, consequently, aggregation increment in the soil. A similar situation was proven by Balin et al (2017), which affirm that from the 0.10-0.20 m layer in a Red Oxisol, the area of NF presented higher MGD regarding areas with anthropic activity. According to the authors above, this fact highlights the greater state of organization of the soil under the natural system, even in the condition of less organic carbon and total.…”

Soil organic matter fractions and carbon management index under integrated crop-livestock system

“…Corroborating with this work, Gazolla et al (2015), found the highest values of CMI in the area of ICLS, due to the higher contributions of organic matter by the grass root system (corn and Brachiaria), especially the Brachiaria crop. However, for Balin et al (2017), evaluating the CMI of a Red Latosol under different systems of use, found that LAB, LABI, and CMI values were lower in the ICLS area compared to the reference area (Forest). However, present potential for C preservation and recovery in their compartments compared to more conservationist systems.…”

“…J., Uberlândia, v. 36, n. 3, p. 743-760, May/June 2020 http://dx.doi.org/10.14393/BJ-v36n3a2020-47702 physical fractionation (CAMBARDELLA; ELLIOTT, 1992), the oxidation fractionation (CHAN;BOWMAN;OATES, 2001), the chemical fractionation (SWIFT, 1996;MADARI;MACHADO, 2003), and the carbon management index (CMI) (BLAIR;LEFROY;LISLE, 1995). Among these, the form used as an indicator of soil quality, more sensitive to changes in management, is the physical granulometric fractionation of soil in Particulate Organic Carbon (POC) and Organic Carbon Associated with Minerals (OCAM) (BALIN et al, 2017;FACCIN et al, 2016), because they are based on the degree of association of SOM with the soil matrix (GAZOLLA et al, 2015). Carbon is called POC when it is free or weakly associated with soil particles, or OCAM, when C is strongly bound to the mineral particles, forming organicmineral complexes (GAZOLLA et al, 2015).…”

Total organic carbon and the humic fractions of the soil organic matter in silvopastoral system

“…Moreover, the studied native vegetation area had a wide variety of plant species and dense vegetation, with decomposition of plant remains at different velocities, which contributes in maintaining the carbon content in the labile fractions of the soil organic matter. In a study by Balin et al (2017), the OCp fraction of native vegetation represented 73% from the Table 1. Mean stocks from total organic carbon (TOC), organic carbon associated with minerals (OCam) and particulate organic carbon (OCp) in areas of native vegetation of Cerrado (NV), Urochloa brizantha cv.…”

“…However, there is often little change in the total organic carbon stocks in a short time span. Considering this, studies suggest using other SOM fractions for evaluating the effect of the land-use systems, emphasizing mainly the SOM granulometric fractions (particulate and associated with minerals organic carbons) and the humic fractions (fulvic acid, humic acid and humine) (Loss et al, 2014;Balin et al, 2017;Nanzer et al, 2019). In addition to these fractions, CMI can also be used as an alternative for assessing the soil quality, as values greater than 100 are an indicative that the agricultural production systems are being beneficial for the soil (Blair et al, 1995).…”