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 Monitoring the spatial variability of soil attributes is an important tool in crop management. Multivariate statistical methods and geostatistics were jointly applied to evaluate the infl uence of different attributes on spatial variability in the soil. The aim of this research was to apply multivariate principal component analysis to map the spatial variability of the soil in an area subjected to different methods of conservation management and identify the most relevant physical and chemical attributes. Disturbed and undisturbed soil samples were collected and georeferenced at 99 different points in the study area at depths of 0.00 - 0.10 m and 0.10 - 0.20 m to measure the physical and chemical attributes of the soil; multivariate principal component analysis (PC) was then applied to the data. Geostatistics was applied to the PCs showing greater explanatory capacity, evaluating spatial dependence, and generating maps of spatial variability. The variance in the soil attributes was explained by the first eight PCs. Soil density, particle density and pH had the greatest infl uence on the spatial variability of the soil since they showed the highest correlation with the PC with the greatest explanatory power. The PCs that correlated with at least two of the soil attributes showed moderate (PC1 and PC6) and strong (PC2, PC4 and PC5) spatial dependence. The generated maps helped identify the joint infl uence of the variability of the most relevant attributes, making it possible to characterise regions under different methods of conservation management. 9 000 0 00 0.0 010 10 0.1 020 20 0.2 (PC data capacity dependence power PC1 PC6 PC2, PC2 (PC2 PC5 0. 01 1 02 2

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 (

ABSTRACT Currently in Brazil, large grain cultivation projects on Plinthosols are a reality, however, there is little or no knowledge of the real mechanism of formation of the plinthite feature, in addition to what is reported in the literature as being a product of oxidation-reduction processes of iron element. This study evaluates iron redoximorphic features and investigates their chemical and mineralogical composition in two profiles of Plinthosols from the Araguaia River plain (P1 and P2). The study strengthens the understanding of the pedogenetic processes involved in the formation of mottles and plinthite. In this sense, it assesses whether the formation mechanisms corroborate the literature. Soil features were sampled in the upper right and left position at the initial plinthic horizon, upper right and left position at the main plinthic horizon, and lower right position at the base horizon of the plinthite zone in the profile. Separated samples comprising the soil matrix, mottles, and plinthite under natural moisture conditions were ground into powder form for chemical determinations by X-ray fluorescence (XRF), sulfuric acid attack (H2SO4), sodium dithionite-citrate-bicarbonate (DCB), and ammonium acid oxalate; and mineralogical determinations by X-ray diffraction. Iron contents in all determined forms were always higher in the plinthite feature, intermediate in the mottle feature, and lower in the soil matrix feature. Most of the Fe in all redoximorphic features is included in the structure of primary minerals and their derivatives (vermiculite, illite, and VHEs). Only part of the iron present (about 35.40 % in P1 and 41.98 % in P2) is detected in the form of oxides such as goethite and hematite, which could be formed in redox processes. The mottle and plinthite features under study are not the product of the classic process of segregation, mobilization, and accumulation of iron as a consequence of redox processes. These features were formed or emerged as a result of a relatively slow and constant weathering process of their source material, which is gradually decomposed in an aqueous medium, releasing most of its components. These components include iron and more mobile elements such as bases and silicon, which leave the system through drainage water, and of which a small part may eventually recombine to form new less complex minerals such as kaolinite and oxides. Brazil reality however feature oxidationreduction oxidation reduction element P (P P2. P2 . sense profile Xray X ray XRF, XRF , (XRF) H2SO4, H2SO4 HSO H SO (H2SO4) dithionitecitratebicarbonate dithionite citrate bicarbonate DCB, DCB (DCB) oxalate diffraction vermiculite, vermiculite (vermiculite illite VHEs. VHEs VHEs) about 3540 35 40 35.4 4198 41 98 41.9 hematite segregation mobilization material medium silicon water (XRF H2SO (H2SO4 (DCB 354 3 4 35. 419 9 41. (H2SO

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 More information is needed on the potential of using drill cuttings (crushed rocks) from the oil industry in agriculture and forestry. An experiment in forest nursery was carried out to evaluate the influence of substrates formulated from onshore gravel on characteristics of Ipê-branco (Tabebuia roseoalba) seedlings (i.e., growth, quality, and nutrition). We used five gravimetric proportions of gravel from drill cuttings mixed with Pinus-bark - commercial substrate (Mecplant® Florestal 3): control with only commercial substrate and zero gravel (G0), 2.5 % gravel (G2.5), 5 % gravel (G5), 7.5 % gravel (G7.5), and 10 % gravel (G10). In general, high proportion of drill cuttings increases density and decrease current moisture and total porosity of the formulated substrates. The drill cuttings proportions G2.5, G5 and G7.5 significantly contributed to the available water and readily available water in these substrates, with percentage values ranging 23 – 30 % higher than the G10 substrate. Increasing the gravel proportion generally resulted in increased pH levels, P, Na, K and metals (Cu, Fe, Ni, Mn, Cd, Zn, Cr and Pb), except for Ca and Mg nutrients that decreased. Heavy metal contents in all substrates did not exceed the permissible values in legal standards. The G2.5 and G5 substrates increased by 20 % approximately the stem diameter and height of seedlings, and G2.5 proportion also affected the root dry mass and Dickson quality index, with values two times higher than G0 substrate. Multivariate analysis proved suitable as a complementary approach to evaluate the seedling quality. Drilling cuttings addition, in general, increased the accumulation of nutrients and heavy metals of the Ipê-branco seedlings, and G2.5 and G5 substrates provided the greatest accumulation of the nutrients P, Ca, Pb and Zn in the shoot, while G2.5 proportion contributed with higher accumulation of N, Ca, Fe, Cr, Mn and Pb in the root. Adding drill cuttings as a conditioning component of the substrate at 2.5 and 5 % proportions is a viable alternative for using this residue to produce high-quality Tabebuia roseoalba seedling. crushed rocks forestry Ipêbranco Ipê branco i.e., ie i e (i.e. growth nutrition. nutrition . nutrition) Pinusbark Pinus bark Mecplant® Mecplant (Mecplant 3 3) G0, G , (G0) 25 2 2. G25 G2 (G2.5) G5, (G5) 75 7 7. G7.5, G75 G7 (G7.5) 1 G10. (G10) general G7. G1 levels P Na Cu, Cu (Cu Fe Ni Cd Pb, Pb) decreased standards G2. index addition shoot N highquality i.e. (i.e (G0 (G2.5 (G5 (G7.5 (G10 i.e (G (G2. (G7. (G1 (G2 (G7

ABSTRACT Native species planted in areas previously occupied by degraded pasture can play an important role in biomass supply and atmospheric carbon sequestration. Evaluating the performance of native species in different planting spacings becomes important for forestry and the management of new species with economic potential. Schizolobium parahyba var. amazonicum is a non-traditional species in the southeastern region of Brazil and it was established in pasture areas to evaluate growth, biomass, and carbon stock. Five planting spacings (3 m x 2 m, 3 m x 3 m, 4 m x 3 m, 4 m x 4 m, and 5 m x 5 m, in monoculture) were tested in 9 experimental plots. The biomass of the shoot and root, as well as the carbon content, were obtained by the direct method. The biomass varied 31.4 and 52.9 kg tree-1 in the spacing 3 m x 2 m and 5 m x 5 m, respectively. The greater carbon stock was observed in the lower spacing (19.43 Mg ha-1), 50% higher than in the larger spacing. The spacing did not influence the biomass and carbon stock in the roots per unit area. The performance of the species should be monitored at advanced ages given the different responses to planting spacing and competition between plants. sequestration potential var nontraditional non traditional growth ( monoculture plots root content method 314 31 31. 529 52 52. tree1 tree 1 tree- respectively 19.43 1943 19 43 (19.4 ha1, ha1 ha , ha-1) 50 area plants 19.4 194 (19. ha-1 19. (19 ha- (1

RESUMO Espécies nativas plantadas em locais anteriormente ocupados por pastagem degradada podem desempenhar um papel importante no suprimento de biomassa e no sequestro de carbono atmosférico. Avaliar o desempenho das espécies nativas em diferentes espaçamentos de plantio se torna importante para a silvicultura e o manejo de novas espécies com potencial econômico. Schizolobium parahyba var. amazonicum é uma espécie não tradicional na região sudeste do Brasil, e foi estabelecida em área de pastagem com objetivo de avaliar o crescimento, a biomassa e o estoque de carbono. Foram testados cinco espaçamentos de plantio em monocultivo (3 m x 2 m, 3 m x 3 m, 4 m x 3 m, 4 m x 4 m e 5 m x 5 m) com 9 parcelas experimentais. A biomassa da parte aérea e radicular, bem como o teor de carbono foram obtidos por meio do método direto. A biomassa variou 31.4 and 52.9 kg árvore-1 nos espaçamentos 3 m x 2 m e 5 m x 5 m, repectivamente. O maior estoque de carbono foi observado no espaçamento mais adensado (19.43 Mg ha-1), sendo 50% maior do que no espaçamento menos adensado. O espaçamento não influenciou a biomassa e o estoque de carbono nas raízes por unidade de área. O desempenho da espécie deveria ser monitorado em idades avançadas dado as diferentes respostas ao espaçamento de plantio e competição entre plantas. atmosférico econômico var Brasil crescimento ( experimentais radicular direto 314 31 31. 529 52 52. árvore1 árvore 1 árvore- repectivamente 19.43 1943 19 43 (19.4 ha1, ha1 ha , ha-1) 50 plantas 19.4 194 (19. ha-1 19. (19 ha- (1

ABSTRACT Climate-smart agriculture (CSA) practices, mainly no-tillage (NT), cover cropping (CC), soil fertilization with organic amendments (OA), and crop-livestock (CL) and crop-livestock-forestry (CLF) systems, has been widely adopted in areas from Brazilian Cerrado. The CSA may partly offset former soil C losses and contribute to climate change mitigation. However, contradictory findings brought uncertainties about the effect of CSA on soil C. Here, by a systematic review of 87 papers and using 621 data pairs, we provided a pervasive biome-scale analysis of soil C stock changes associated with the adoption of CSA across Brazilian Cerrado. All CSA practices evaluated showed average positive rates of C stock change, indicating a general tendency of soil C accretion after its adoption. In areas under NT, CC and CLF, greater rates were estimated for the deeper soil profile evaluated (0.00-1.00 m) (1.24 ± 0.85, 0.54 ± 0.54 and 1.00 ± 1.47 Mg ha–1 yr–1, respectively), while OA and CL showed more soil C accretion when the assessment was limited down to 0.10 m depth (0.82 ± 0.60 and 0.59 ± 0.66 Mg ha–1 yr–1, respectively). Unfortunately, the lack of basic information precluded any attempt to statically compare our estimations. In this sense, we must be cautious in stating that soil C sequestration occurs at those rates after the adoption of CSA practices. Despite these limitations, the results clearly show that the diversification and intensification of agricultural areas in the Cerrado by the adoption of CSA is a promising pathway to increase soil C stocks, and consequently, contribute to climate change mitigation and adaptation. Finally, our findings emphasize the importance of efforts that stimulate farmers to adopt these practices on large scale, such as Brazil’s Low-Carbon Agriculture Plan, besides providing sound empirical evidence about the role of soil C sequestration in Brazil achieving its Nationally Determined Contributions commitments. Climatesmart Climate smart (CSA notillage no tillage NT , (NT) CC, (CC) OA, (OA) croplivestock crop livestock (CL croplivestockforestry forestry CLF (CLF systems However Here 8 62 pairs biomescale biome scale 0.001.00 000100 0.00 0 00 1 (0.00-1.0 1.24 124 24 (1.2 085 85 0.85 054 54 0.5 100 1.0 147 47 1.4 ha1 ha ha– yr1 yr yr–1 respectively, respectively respectively) 010 10 0.1 0.82 082 82 (0.8 060 60 0.6 059 59 066 66 respectively. . Unfortunately estimations sense limitations stocks consequently adaptation Finally Brazils s LowCarbon Low Carbon Plan commitments (NT (CC (OA 6 001 0.001.0 00010 000 0.0 (0.00-1. 1.2 12 2 (1. 08 0.8 05 5 0. 1. 14 4 yr– 01 (0. 06 0.001. 0001 (0.00-1 (1 (0 0.001 (0.00- ( (0.00 (0.0

ABSTRACT Soil mapping is a permanent demand, but the traditional method does not allow fast execution and low cost. Digital soil mapping (DSM) aims to improve the process by working with models that treat soil spatial variability quantitatively. In this perspective, the objective of the study is to perform DSM of the Parnaíba River Delta, Northeastern Brazil, through the decision tree (DT) integration technique using a set of attributes derived from the digital elevation model (DEM) and satellite images as input parameters. Data matrices were created considering different soil groups. The performance of the J48 machine learning algorithm (DT) was assessed for a set of two data matrices: one elaborated for the mapping units of the pre-existing conventional pedological map and the other for a set of associations determined based on the characteristics of the landscape of the study area with close correlation with the existing soils, mainly due to the source material. From the data processing, digital soil maps were created and validated by means of error matrices, whose reference points were classified in the field and validated using a pre-existing traditional soil map of the area. The results revealed that the attributes derived from satellite images stood out from those derived from DEM in predicting soil groups. Based on the validation coefficients applied (overall accuracy, Kappa index, user’s accuracy and producer’s accuracy), the classification quality was satisfactory, despite the complexity of the environment. demand cost (DSM quantitatively perspective Delta Brazil DT (DT (DEM parameters groups J J4 preexisting pre soils material processing overall index users user s producers producer , accuracy) satisfactory environment

ABSTRACT Soil quality can be understood as its capacity to provide several essential services within the ecosystem and has been used to understand the impact of different managements, providing information that proves the benefits and your maintenance of the agroecosystem. To understand the impact of different managements, this study aimed to compare the chemical, physical, and biological soil properties in pasture areas managed with different recovery times in an integrated crop-livestock system about perennial pastures and secondary forest. The following management systems were evaluated: Secondary Forest (SF), Perennial Pasture (PP), pasture recovered to five years through the intercropping corn + Brachiaria brizantha (Palisade grass) (ICL5), and pasture recovered to eight years through the intercropping corn + Brachiaria brizantha (Palisade grass) (ICL8). Different soil properties were evaluated, namely: Chemical: pH, H+Al, Al 3+ , P, K + , Ca 2+ , Mg 2+ , TOC, SB, CEC, V, and m; Physical: soil bulk density (Bd), total porosity (Tp), macroporosity (Ma), microporosity (Mi), soil resistance to penetration (Pr), and gravimetric soil water content (GWc); and biological: soil microbial biomass carbon (SMB-C), basal soil respiration (BSR), metabolic quotient (qCO 2 ), and microbial quotient (qMic). Perennial pasture and ICL8 areas were the ones that most contributed to the increase in nutrients (Ca 2+ , Mg 2+ , and K + ), TOC and sorption complex. The ICL8 area showed the best results in soil physical variables Ma, Tp, Pr, and GWc were the best results for the ICL8 area. Secondary forest and ICL8 areas presented the best results from SMB-C and qMic. Between periods of pasture recovery through the integration of crops and livestock, the longer the recovery time, the greater its beneficial effects on the different chemical, physical and biological soil properties, overcoming secondary forest and perennial pasture. managements agroecosystem chemical croplivestock crop livestock evaluated SF, SF (SF) PP, PP (PP) Palisade grass ICL5, ICL5 ICL (ICL5) ICL8. . (ICL8) namely Chemical pH HAl H H+Al 3 P SB CEC V m Physical Bd, Bd (Bd) Tp (Tp) Ma (Ma) Mi, Mi (Mi) Pr (Pr) (GWc) SMBC, SMBC SMB C (SMB-C) BSR, BSR (BSR) qCO ) qMic (qMic) complex time (SF (PP (ICL5 (ICL8 (Bd (Tp (Ma (Mi (Pr (GWc (SMB-C (BSR (qMic (ICL

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-

ABSTRACT Adopting land-uses that contribute with a considerable litter input can affect the accumulation, protection, and bioavailability of organic carbon in the edaphic environment, compromising the different compartments of soil organic matter (SOM) and the associated benefits. Moreover, changes in seasons can influence the dynamic of SOM. Notably, the mechanisms involved in SOM stabilization and storage, particularly in agroforestry production areas, are still poorly explored. This study aimed to verify if the contents of soil organic carbon (SOC) and the physical fractions of the SOM are modified as a function of agroforestry systems implemented in the short term, and verify if seasonality can affect the compartmentalization of SOM in agrifood systems. Also, we tested if the carbon management index (CMI) is sensitive to detecting management practices quality across the unmanaged pasture, different agroforestry systems, and a reference area (forest). We measured soil physical properties, SOC content in bulk soil, particular organic carbon (POC), and mineral-associated organic carbon (MAOC) fractions at three different depths (0.00-0.05, 0.05-0.10, and 0.10-0.20 m) in response to the adoption of agroforestry systems. Our results show that after a short period of implementation of agroforestry systems, significant changes were observed in SOC contents and the physical fractions of SOM in the most superficial layers (0.00-0.05 and 0.05-0.10 m), with emphasis on the particulate fraction of SOM. We verified that the seasonality affected the SOC, POC, and MAOC contents. We also found that the CMI index was more sensitive and efficient in detecting changes arising from seasonality and the management practices involved. According to this index, it was possible to verify that the agroforestry system with the highest density of species for biomass production (AS3) has been accumulating more carbon in the soil. Therefore, this study provides relevant information regarding soil carbon management in agroforestry systems. landuses land uses accumulation protection environment (SOM benefits Moreover Notably storage areas explored (SOC term Also (CMI pasture forest. forest . (forest) properties POC , (POC) mineralassociated mineral (MAOC 0.000.05, 000005 0.00 0.05, 0 00 05 0.050.10, 005010 0.05 0.10, 10 0.100.20 010020 0.10 0.20 20 0.10-0.2 m 0.000.05 (0.00-0.0 0.050.10 0.05-0.1 m, AS3 AS (AS3 Therefore (forest (POC 000 00000 0.0 005 050 00501 010 1 100 0.100.2 01002 0.1 020 0.2 2 0.10-0. 0.000.0 (0.00-0. 0.050.1 0.05-0. (AS 0000 0. 0050 01 0.100. 0100 02 0.10-0 0.000. (0.00-0 0.050. 0.05-0 0.100 0.10- 0.000 (0.00- 0.050 0.05- (0.00 (0.0 (0. (0 (

ABSTRACT There is a need for greater knowledge about the medium- and long-term effects of prescribed fire management on soil in ecosystems prone to wildfires and more vulnerable to climate change. This study examined the short- and medium-term effects of prescribed fire on soil chemical properties and chemical fractions of soil organic matter (SOM) in two positions of the landscape in a high-elevation grassland environment. The ecosystem is located in the mountain peaks of southeastern Brazil associated with the Atlantic Forest biome. Prescribed fire was conducted in 2017 to reduce understory vegetation and thus prevent potential severe wildfires. Soil samples were collected at the layers of 0.00-0.10, 0.10-0.20, and 0.20-0.40 m, at eight composite sampling. The composite samples were collected on five different occasions: before the prescribed fire, and 10, 30, 90, and 240 days after the prescribed fire. Soil chemical properties, total organic carbon, labile C, and chemical fractionation of SOM were analyzed. All soil properties investigated were affected by the prescribed fire, with variations in landscape position, duration of effect, and soil layer. In the backslope area, the medium-term effect of fire was negative and induced soil degradation and induced soil degradation. In the footslope area, the system showed greater resilience to the effects of fire, as indicated by the recovery of the soil’s chemical properties. These results can help assess the suitability of controlled burning of vegetation for managing risks of fire in mountainous regions, such as high-elevation grasslands. medium longterm long term change short mediumterm (SOM highelevation high elevation environment biome 201 0.000.10, 000010 0.00 0.10, 0 00 10 0.00-0.10 0.100.20, 010020 0.10 0.20, 20 0.10-0.20 0.200.40 020040 0.20 0.40 40 0.20-0.4 m sampling occasions 30 90 24 carbon C analyzed position layer area soils s regions grasslands 000 0.000.10 00001 0.0 010 1 0.00-0.1 100 0.100.20 01002 0.1 020 2 0.10-0.2 200 0.200.4 02004 0.2 040 0.4 4 0.20-0. 3 9 0.000.1 0000 0. 01 0.00-0. 0.100.2 0100 02 0.10-0. 0.200. 0200 04 0.20-0 0.000. 0.00-0 0.100. 0.10-0 0.200 0.20- 0.000 0.00- 0.100 0.10-

ABSTRACT Vast areas of the Brazilian Amazon have been deforested for the expansion of livestock and the agricultural frontier, which has resulted in soil exhaustion. It is therefore urgent to reduce deforestation and encourage sustainable land use to promote social and economic development in the region. The aim of this study was to evaluate the impact of different land use systems (an agroforestry system, cassava cultivation, non-degraded pasture, native forest) on the chemical properties of the soil (0-40 cm) in the mesoregion of the Juruá Valley, in the state of Acre, Brazil. Principal component analysis showed the soil in the forested area (reference) has greater values for P, Ca2+, Mg2+, K+, Na+, sum of bases, and cation exchange capacity; while hierarchical cluster analysis suggested little dissimilarity to the soil in the agroforestry system, and high dissimilarity to the soil in the areas of cassava cultivation and pasture. The results therefore support agroforestry as the most sustainable land use system, compared to cassava cultivation or pasture. frontier exhaustion region an system nondegraded non degraded pasture forest 040 0 40 (0-4 cm Valley Acre Brazil reference (reference P Ca2 Ca Ca2+ Mg2 Mg Mg2+ K K+ Na Na+ bases capacity 04 4 (0- (0 (