ABSTRACT Agroecological management is considered a model of sustainable agriculture that offers social, environmental and economic benefits. The hypotheses of this study were that agroecological production systems can promote changes in the physical fractions of soil organic matter (SOM) associated with aggregates of different origins, and that the greater diversity of plant species in the production system may favour an increase in the carbon concentration of these aggregates. The aim of this study was to a) determine the mass of the free light fraction (FLF), intra-aggregate light fraction (ILF) and light organic matter fraction (LOM) of biogenic and physiogenic soil aggregates; and b) quantify the organic carbon content of the three light SOM fractions and the residual particulate SOM fraction. Five production systems were evaluated: AgF - Agroforestry system; CSun - Coffee grown in full sun; CSha - Coffee grown in shade; FLE - Flemingia grown in alleys; and NT - No-tillage. The aggregates were separated, identified and classified according to their origin or formation pathway into biogenic (formed by biological processes) or physiogenic aggregates (resulting from chemical and physical actions). From these, the mass and carbon content of the FLF, ILF, LOM and residual particulate fractions were quantified. The greater diversity of plant species found in the AgF system has not yet favoured an increase in the carbon content of the aggregates. The longer set-up time and the management practices of the CSun system has led to an increase in the carbon content of the organic fractions of the aggregates (3.44-1.63 g kg-1 for C-LOM; 1.93-1.13 g kg-1 for C-FLF). The lowest overall mean values for LOM and ILF were found mainly in the aggregates of the NT system (1.22-1.67 and 1.55-2.20 g kg-1, respectively), being associated with the shorter time and greater mobilisation of the arable layer. Biogenic aggregation afforded the highest overall mean values for LOM, and increased the mass of the light fractions (15.5%-27.8% for FLF; 23.4%-8.0% for ILF) and the carbon in the C-LOM, C-FLF and residual particulate fractions (42.3%, 12.9%, and 35.0%, respectively) in the surface layer, suggesting an improvement in soil quality. social benefits (SOM origins FLF , (FLF) intraaggregate intra aggregate (ILF (LOM b evaluated sun shade alleys Notillage. Notillage No tillage. tillage No-tillage separated formed processes resulting actions. actions . actions) quantified setup set up 3.441.63 344163 3.44 1.63 3 44 1 63 (3.44-1.6 kg1 kg kg- CLOM C C-LOM 1.931.13 193113 1.93 1.13 93 13 1.93-1.1 CFLF. CFLF C-FLF) 1.221.67 122167 1.22 1.67 22 67 (1.22-1.6 1.552.20 155220 1.55 2.20 55 2 20 1.55-2.2 kg1, 1, respectively, respectively layer 15.5%27.8% 155278 15.5% 27.8% 15 5 27 8 (15.5%-27.8 23.4%8.0% 23480 23.4% 8.0% 23 4 0 23.4%-8.0 CLOM, 42.3%, 423 42 (42.3% 129 12 9 12.9% 350 35 35.0% quality (FLF 441 3.441.6 34416 344 3.4 163 1.6 6 (3.44-1. 931 1.931.1 19311 193 1.9 113 1.1 1.93-1. 221 1.221.6 12216 122 1.2 167 (1.22-1. 552 1.552.2 15522 155 1.5 220 2.2 1.55-2. 15.5%27.8 15527 15.5 278 27.8 (15.5%-27. 23.4%8.0 2348 234 23.4 80 8.0 23.4%-8. 42.3% (42.3 12.9 35.0 3.441. 3441 34 3. 16 1. (3.44-1 1.931. 1931 19 11 1.93-1 1.221. 1221 (1.22-1 1.552. 1552 2. 1.55-2 15.5%27. 15. 27. (15.5%-27 23.4%8. 23. 8. 23.4%-8 42.3 (42. 12. 35. 3.441 (3.44- 1.931 1.93- 1.221 (1.22- 1.552 1.55- 15.5%27 (15.5%-2 23.4%8 23.4%- 42. (42 (3.44 (1.22 15.5%2 (15.5%- (4 (3.4 (1.2 (15.5% ( (3. (1. (15.5 (3 (1 (15. (15

Abstract This work aimed to evaluate the effectiveness of forest restoration consortium or not with eucalyptus in the recovery of edaphic attributes. Three of them were managed with the following forest restorations: natural regeneration after clear cutting of eucalyptus planting (RP), planting of native species after clear cutting of eucalyptus planting (RA) and planting of native species after cutting 50% of eucalyptus planting (RAE), and of a secondary forest (FR). Sixteen (16) soil samples were collected in each area for the analysis of the physical and chemical attributes. The restoration with RA promoted a less acidic pH, lower Al 3+ content, higher P content and higher V%, similar to FR. The RAE and RP restorations favor an increase in SB, CTC, N and in the organic carbon content. attributes RP, , (RP) (RA 50 RAE, (RAE) FR . (FR) 16 (16 pH 3 V V% SB CTC (RP 5 (RAE (FR 1 (1 (

Resumo A erosão hídrica é uma das principais causas da degradação das terras agricultáveis brasileiras, levando à diminuição da produtividade das culturas e à acidificação do solo, prejudicando sua capacidade de armazenar carbono, nutrientes e água. O manejo inadequado do solo é um dos principais responsáveis por esse tipo de degradação. A identificação da intensidade da erosão pode ser feita por meio da utilização de atributos indicadores que são altamente sensíveis as mudanças no ambiente edáfico. O estudo teve como objetivos: i) analisar os atributos físicos e químicos do solo em áreas de voçorocas com diferentes graus de degradação/estabilização; e ii) verificar a viabilidade de utilização desses atributos como indicadores de recuperação ambiental. O estudo foi realizado em quatro áreas com diferentes graus de formação de voçorocas: a) inicial, intermédia, madura e senil. As amostras foram coletadas nas faces externa e interna de cada voçoroca no final da estação seca. Entre os atributos físicos avaliados, a densidade do solo e a porosidade total foram os mais significativamente alterados. A avaliação dos microagregados permitiu conhecer a qualidade do solo através de frações como a argila dispersável em água, a argila refloculável em água e a argila não dispersível em água. O carbono total, o nitrogênio total e a relação C/N elucidaram a dinâmica da perda de solo e de nutrientes em diferentes fases dos processos de formação e estabilização da erosão, com valores mais baixos observados na face interna das voçorocas em comparação a externa. Observou-se que a vegetação influenciou os resultados dos atributos físicos e químicos. No geral, os valores tenderam ao equilíbrio entre as faces na voçoroca SE, indicando maior estabilização. Com base nesses resultados, os atributos avaliados podem servir como indicadores de qualidade do solo, pois são mais eficientes e sensíveis em expressar a recuperação da qualidade física e química do solo, fornecendo informações valiosas para o monitoramento de processos de degradação e para a prevenção, controle e recuperação de voçorocas no Bioma Mata Atlântica. brasileiras edáfico objetivos i degradação/estabilização degradaçãoestabilização ii ambiental inicial intermédia senil seca alterados CN C N Observouse Observou se geral SE prevenção Atlântica

Abstract Water erosion is one of the primary causes of agricultural soil degradation in Brazil, leading to diminished crop productivity and soil acidification, thereby impairing its ability to store carbon, nutrients, and water. Identifying the intensity of erosion can be achieved by utilizing indicator attributes that are highly sensitive to changes in the edaphic environment. The study analyzed the physical and chemical attributes of soil in areas with gullies exhibiting varying degrees of degradation/stabilization. The study was conducted across four areas with varying degrees of gully formation: a) initial, intermediate, mature, and senile. Samples were collected from both the external and internal sides of each gully at the end of the dry season. Among the physical attributes assessed, soil density and total porosity were found to be the most significantly altered. Evaluation of microaggregates provided insights into soil quality through fractions including water-dispersible clay, water-reflocculable clay, and non-water-dispersible clay. Total carbon, total nitrogen, and the C/N ratio elucidated the dynamics of soil and nutrient loss across different stages of erosion formation and stabilization processes, with lower values observed on the internal side of the gullies compared to the exterior side. Vegetation was observed to influence the results of the physical and chemical attributes. Overall, the values tended towards equilibrium between the faces at the senile stage, indicating greater stabilization. Brazil acidification carbon nutrients water environment degradationstabilization degradation/stabilization a initial intermediate mature season assessed altered waterdispersible dispersible clay waterreflocculable reflocculable nonwaterdispersible non nitrogen CN C N processes Overall stage

ABSTRACT In the Cerrado, the palm swamps ( veredas ) are characterized by being humid and stable environments that lead to the formation of Histosols ( Organossolos ). and soils with surface horizons of organic constitution, which are fragile and sensitive to anthropic action. This study aimed to evaluate the impact of anthropization (recurrent forest fires and livestock farming) on the chemical, physical and morphological properties of soils in two palm swamps in the Environmental Preservation Area (EPA) of Pandeiros River, Minas Gerais, namely: Água Doce, in preserved condition, and Taboa, in anthropized condition. Four soil profiles were morphologically described, two profiles in each palm swamp, with subsequent chemical and physical analyses, calculations of organic carbon stock and identification of the origin of organic matter. The results were analyzed using descriptive statistics and Pearson’s correlation coefficient. Soil morphological properties were influenced by vegetation cover, drainage and anthropization conditions. As for the physical and chemical properties, adequate values were observed in the preserved palm swamp, including lower bulk density values and higher cation contents. Anthropic actions in the anthropized palm swamp caused degradation of soils, revealed by subsidence, reduction in organic carbon content, increase in bulk density and decrease in fertility. Changes promoted in the soils of the palm swamps compromise ecosystem services, indicating that actions at either local or governmental level should be stimulated for the preservation and conservation of these environments. Cerrado . constitution action recurrent farming EPA (EPA River Gerais namely Doce condition Taboa described analyses matter Pearsons Pearson s coefficient cover conditions contents subsidence content fertility services

ABSTRACT Sandy texture soils have a great expression in agricultural areas worldwide. In the Baixada Fluminense, soils with a sandy texture on the surface horizons are striking, and a good part of these areas is destined for producing vegetables using conventional cultivation methods. The sandy texture is one of the great challenges for agriculture due to the low water retention capacity provided to the soil, the rapid decomposition of organic matter, and the intense loss of nutrients by leaching. In these areas, the action of erosive processes is sometimes observed, whether water or wind erosion. The practices carried out in conventional agriculture can accentuate these processes. This study aimed to evaluate the influence of different soil management systems, with different vegetation covers, on the pathways of aggregate formation, the nutrient contents contained therein, and the organic matter fractions, with the objective of using these properties as indicators of soil quality. The study was carried out in an organic production unit, with no-till system (NT) and conventional system (CT), three vegetal covers were evaluated, namely; seed cocktail 1 (C1) (Crotalaria (Crotalaria juncea) (20 kg ha-1), Jack Bean (Canavalia ensiformis) (150 kg ha-1) and millet (Pennisetum glaucum) (60 kg ha-1)), and seed cocktail 2 (C2) (with 50 % of the amount of seeds used in C1), and spontaneous plants (S. P). Undisturbed samples were collected at the layers of 0.00-0.05 and 0.05-0.10 m, and, from these samples, aggregates with a diameter between 9.7 and 8.0 mm were classified according to the formation route (Biogenic or Physicogenic). From these, the chemical properties were quantified (pH, Ca2+, Mg2+, Al3+, P, Na+, K+), and also the carbon fractions (total organic carbon – TOC, mineral-associated organic carbon – MAOC), particulate organic carbon – POC, and free light fraction carbon – LFC). Based on the results, it was verified that the percentage of biogenic aggregates was higher than the physicogenic one in the layer of 0.00-0.05 m, not being verified influences of the vegetal coverage or the management system. Chemical properties did not differ significantly between training pathways. The CT, for the most part, was the system in which the highest values of chemical properties were observed, and in general, the C2 and S.P coatings were the ones that provided the greatest improvements for chemical properties and carbon content. worldwide Fluminense striking methods leaching observed erosion systems therein quality unit notill no till NT (NT CT , (CT) evaluated namely C1 C (C1 Crotalaria juncea 20 (2 ha1, ha1 ha Canavalia ensiformis 150 (15 ha-1 Pennisetum glaucum 60 (6 ha-1)) (C2 5 C1, C1) S. S (S P. P . P) 0.000.05 000005 0.00 0.05 0 00 05 0.00-0.0 0.050.10 005010 0.10 10 0.05-0.1 m 97 9 7 9. 80 8 8. Biogenic Physicogenic. Physicogenic Physicogenic) pH, pH (pH Ca2 Ca Ca2+ Mg2 Mg Mg2+ Al3 Al Al3+ Na Na+ K+, K K+ K+) total TOC mineralassociated mineral associated MAOC, MAOC MAOC) POC LFC. LFC LFC) results general SP content (CT (C ( 15 (1 ha- 6 000 0.000.0 00000 0.0 005 0.00-0. 050 0.050.1 00501 010 0.1 0.05-0. 0.000. 0000 0. 0.00-0 0.050. 0050 01 0.05-0 0.000 0.00- 0.050 0.05-