Variabilidade espacial das frações da matéria orgânica do solo em área degradada sob recuperação

Abstract

R E S U M OObjetivou-se, neste estudo, avaliar a variabilidade espacial das frações da matéria orgânica do solo em uma área degradada em recuperação com pinhão-manso; para isto se estabeleceu, em um Argissolo Vermelho-Amarelo, uma malha de 30 por 30 m para amostragem, totalizando 55 pontos. Em cada ponto foram coletadas amostras de solo nas camadas de 0-0,05; 0,05-0,10 e 0,10-0,20 m e determinados carbono orgânico total (COT), carbono lábil (CL) e o carbono das frações ácido fúlvico (C-FAF), ácido húmico (C-FAH) e humina (C-HUM). Os maiores teores de COT foram observados na camada de 0-0,05m e variaram de 2,0 a 15,5 g kg Spatial variability of the soil organic matter fractions in degraded area under recovery A B S T R A C TThe present study aimed to evaluate the spatial variability of soil organic matter fractions in degraded area under recovery by planting Jatropha curcas. For this purpose, a grid of 30 by 30 m was established for sampling, totalizing 55 points. At each point, soil samples were collected in the 0-0.05, 0.05-0.10 and 0.10-0.20 m depths. Total organic carbon (TOC), labile carbon (LC) and fulvic acid fraction (FAF), humic acid fraction (HAF) and humin fraction (HUM) carbon were determined. The FAF at 0-0.05 and 0.10-0.20 m depths and FAH at 0.10-0.20 m depth showed coefficient of variation of 66, 74 and 77%, respectively, considered high. The other variables showed mean CV ranging from 32 to 58%. With the exception of the FAF and HUM (0-0.05 m), the other attributes showed spatial dependence classified as moderate or strong, varying from 39.6 and 410.9 m. Very low values of the total organic carbon and their fractions highlighted the soil degradation and indicate the need to increase carbon inputs using crops with high amount of residues. Palavras-chave:carbono orgânico do solo substâncias húmicas geoestatística krigagem

Spatialization of Fractions of Organic Matter in Soil in an Agroforestry System in the Atlantic Forest, Brazil

“…The variables C-FAF, C-HUM, COp and COam at 20-40 cm depth presented strong spatial dependence, while the variables C-HAF, TOC, COp and COam (10-20 cm) and TOC (20-40 cm) showed moderate spatial correlation and the COam variable (0-10 cm) presented weak spatial dependence. Leite et al (2015) conducted a study evaluating the spatial variability of SOM fractions in a degraded area under recovery with Jatropha curcas L., in southwestern Piauí, and found different results of the present study. They adjusted the spherical model for the TOC and labile carbon (LC) variables in the 0-5 cm layer, for TOC, C-HAF and C-HUM variables in the 5-10 cm layer and for TOC in the 10-20 cm layer.…”

Spatial Analysis of Granulometry and Humic Substances of an Ecological Restoration Area in the Brazilian Atlantic Forest

“…Humic substances ( Figures 1D, 1E, and 1F) showed a nonuniform distribution pattern in the study area. The findings of the present study agree with the findings of Leite et al [26], who, analyzing the spatial variability of soil organic matter fractions in a degraded recovery area with Jatropha, in southwestern Piauí, Brazil, observed heterogeneous HS distribution.…”

Initial Recovery of Organic Matter of a Grass-Covered Constructed Soil after Coal Mining

“…However, these stocks accounted for only 61 % of the stock in the natural soil. These data agree with those of Leite et al (2015), who found a low C content in the labile and non-labile OM of the 0.00-0.05 m layer of an Acrisol covered with Jatropha curcas for one year, after a long period of degradation by mining and uncontrolled burning and grazing. The HF is considered the OM density fraction with least sensitivity to changes in the soil management/crop systems, because aside from the biochemical recalcitrance of organic molecules and physical protection, the association of OM with soil minerals acts as a protection mechanism.…”