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

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 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 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 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

ABSTRACT Ants mediate ecosystem services that can modulate crop performance and overall agroecosystem functioning. Our study investigated how the activity of Solenopsis invicta Buren (Hymenoptera: Formicidae) influences soil chemical properties, soil silicon pools, and soil phytoliths. We hypothesized Solenopsis invicta Buren activity would increase the macronutrient content, available silicon for plants (PASi), and amorphous silicon (ASi) in nest soils, which is related to changes in the phytolith assemblage. This study was conducted on agricultural soil under organic management, covering an area of approximately 70 ha in Rio de Janeiro State, Brazil. Thirty paired soil and nest samples were collected at a depth of 0.20 m and analyzed to obtain values for soil macronutrients and silicon pools (PASi and ASi) and to perform phytolithic analyses. Phytolith extraction from the samples was undertaken using a protocol that involved removed coatings, clay fractions, and iron oxides through density separation, followed by the determination of the phytolith concentration and identification of a minimum of 200 phytoliths per sample using a Zeiss Axioskop 40 optical microscope. Results indicated an increase in total organic carbon (TOC), phosphorus (P), and potassium (K) levels and in all forms of Si studied. Ants also affected phytolith assemblages, and there was an increase in morphotypes associated with dicotyledonous plants in the nest soil. We assumed these results were derived from bioturbation promoted by ants, predatory activity, and the interaction of some prey and phytoliths, leading to biologically enhanced weathering. By uncovering and describing this novel role for a widely distributed and highly abundant organism in Neotropical soils, we propose that these alterations, particularly in the biogeochemical cycle of silicon, should be added to the list of ecosystem services provided by ants. This study presents the first evidence of alterations in silicon pools and phytolith assemblages caused by the action of ants. functioning Hymenoptera (Hymenoptera Formicidae properties content PASi, PASi , (PASi) ASi (ASi soils assemblage management 7 State Brazil 020 0 20 0.2 analyses coatings fractions separation 4 microscope TOC, TOC (TOC) P, P (P) K (K studied ants weathering 02 2 0. (TOC (P

ABSTRACT The benefits promoted by arbuscular mycorrhizal fungi (AMF) to forest species seedlings include higher growth rate, better nutrition, and higher survival rates. Inoculation with AMF may facilitate revegetation of degraded lands, although it depends on symbionts and environmental conditions, such as soil P availability. In this sense, the lack of information justifies the carrying out of studies of this nature. We investigated the dependence and responsiveness of two forest species native to the Atlantic Forest, Pseudobombax grandiflorum and Bauhinia forficata, to different AMF inocula (isolated AMF species, Dentiscutata heterogama, DH, Gigaspora margarita, GM, Rhizophagus clarus, RC, mixed inoculum with these former three AMF species, MI) compared to the uninoculated control (UC), combined with different P doses applied to the substrate (0, 24, 71, 213, and 650 mg kg-1), under greenhouse conditions. We evaluated root colonization, growth, and nutritional variables for Pseudobombax grandiflorum and Bauhinia forficata, 112 and 116 days after sowing with pre-germinated seeds, respectively. Native forest species exhibited different degrees of mycorrhizal dependence. The highest mycorrhizal dependence of P. grandiflorum seedlings was indicated by significant benefits, both growth and nutritional, promoted by innoculation treatments, under fertilization with the intermediate dose of P (213 mg kg-1). In fact, under this P dose, seedlings responded to a maximum increase in biomass in the GM treatment and maximum concentration of P and N in the shoots in the UC and DH treatments, respectively. The lowest mycorrhizal dependence of B. forficata seedlings was highlighted by significant growth benefits promoted by inoculation treatments under the lowest doses of P (24 or 71 mg kg-1). Under this P dose, we observed seedlings with maximum value of the root:shoot ratio in most of the types of inoculation and also higher values of biomass and height in the MI treatment. The responsiveness in terms of increase in growth and nutritional variables varied depending on the forest species, the dose of P applied to the substrate, and the AMF type of inoculum used. Root biomass and total dry biomass, mainly, should preferably be included in future studies with the same objective as the present study, as they were more relevant to point out the differences between treatments, in comparison with the variables associated with nutritional variables. (AMF rate nutrition rates lands conditions availability sense nature Forest isolated heterogama margarita clarus RC UC, , (UC) 0, 0 (0 24 213 65 kg1, kg1 kg 1 kg-1) colonization 11 pregerminated pre germinated seeds respectively (21 kg1. . fact B (2 7 rootshoot shoot used mainly study (UC ( 2 21 6 kg-1 kg-

ABSTRACT Soil organic matter (SOM) dynamics can be significantly influenced by various cultivation practices, particularly under environmental and edaphic conditions that enhance and accelerate the transformations of organic materials such as straw, root biomass, and organic fertilizers. This study aimed to evaluate the impact of different cultivation and soil management systems on SOM fractions in agricultural areas of the Cerrado Goiano region. The research was conducted across three areas with diverse production systems: 1) BV area, including soybean monoculture (SM01), integrated crop-livestock-forest (ICLF01), pasture (PA01), and Cerrado vegetation (NV01); 2) ML area, featured soybean-corn monoculture succession (SMS02), agroforestry (AF02), pasture (PA02), and native Cerrado vegetation (NV02); and 3) IF area, comprised soybean-corn succession (SMS03), integrated livestock-forest (ILF03), pasture (PA03), and native Cerrado vegetation (NV03). Disturbed and undisturbed soil samples were collected from two layers: 0.00-0.05 and 0.05-0.10 m. Samples were analyzed for total organic carbon, carbon storage, and SOM physical (granulometric and densimetric) and chemical (fulvic acid, humic acid, and humin) fractionations of soil organic matter (SOM). Additionally, water-floatable light organic matter (LOM), the carbon management index, and its components were determined. Soil organic matter fractions were similarly influenced by the characteristics of cultivation and management systems. However, there were more pronounced differences between systems in the BV area compared to the ML and IF areas. Among the parameters studied, LOM proved to be the most efficient and effective in distinguishing SOM input across different cultivation and soil management systems, particularly in pasture systems. (SOM practices straw biomass fertilizers region 1 SM01, SM01 SM , (SM01) croplivestockforest crop livestock forest ICLF01, ICLF01 ICLF (ICLF01) PA01, PA01 PA (PA01) NV01 NV (NV01) 2 soybeancorn corn SMS02, SMS02 SMS (SMS02) AF02, AF02 AF (AF02) PA02, PA02 (PA02) NV02 (NV02) 3 SMS03, SMS03 (SMS03) livestockforest ILF03, ILF03 ILF (ILF03) PA03, PA03 (PA03) NV03. NV03 . (NV03) layers 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 storage granulometric densimetric fulvic acid humin SOM. Additionally waterfloatable water floatable LOM, (LOM) index determined However studied SM0 (SM01 ICLF0 (ICLF01 PA0 (PA01 NV0 (NV01 SMS0 (SMS02 AF0 (AF02 (PA02 (NV02 (SMS03 ILF0 (ILF03 (PA03 (NV03 000 0.000.0 00000 0.0 005 0.00-0. 050 0.050.1 00501 010 0.1 0.05-0. (LOM (SM0 (ICLF0 (PA0 (NV0 (SMS0 (AF0 (ILF0 0.000. 0000 0. 0.00-0 0.050. 0050 01 0.05-0 (SM (ICLF (PA (NV (SMS (AF (ILF 0.000 0.00- 0.050 0.05-

ABSTRACT Precision agriculture (PA) practices in banana production chains have received limited attention. Based on the literature, the investigation of spatial and temporal variability in banana orchards should be customized according to the characteristics of the crop. This study aimed to develop and evaluate methods for mapping the spatial variability in soil properties at row- and clump-resolutions in a banana orchard, and to generate row and clump maps with high-spatial-resolution soil property information. A banana orchard was investigated, and georeferenced soil sampling was conducted with calibration and validation points. Methods for reconstructing banana rows and clumps were proposed, called Methods 1 and 2 and Alternative Methods 1 and 2. Surface and line maps at row- and clump-resolutions for soil chemical and physical properties were generated using ordinary kriging and Voronoi polygons. Subsequently, the discrepancies between the data obtained from the validation points and the predictions devised from the surfaces generated by the proposed approaches were calculated, and the RMSE was used as a performance parameter. Methods 1 and 2 were appropriate and reliable approaches for site-specific management and allow for specific and optimized crop management in banana cultivation, offering greater accuracy in cultivation operations such as fertilization. PA (PA attention literature clumpresolutions resolutions highspatialresolution high resolution information investigated polygons Subsequently calculated parameter sitespecific site fertilization

ABSTRACT Brazilian Soil Classification System (SiBCS) adopts a hierarchical approach to classify soils using specific diagnostic attributes. Organossolos (Histosols) class is differentiated according to its genesis, especially because the parent material is organic, thus requiring diagnostic attributes that describe the unique properties of soil organic matter (SOM). This study aimed to propose the use of labile organic carbon and the C and N contents of humic fractions and their ratios for the family and series levels of the Brazilian Soil Classification System for Organossolos in high mountainous regions. Quantitative chemical fractionation of SOM was performed to obtain the humic fractions and determine the labile oxidizable carbon in 16 Organossolos profiles from Itatiaia National Park, RJ. Carbon and nitrogen contents of the humic acid, fulvic acid, and humin fractions were obtained, as well as the percentages of these fractions in relation to the total carbon and nitrogen in the soil. Carbon and nitrogen ratios were calculated for each fraction. Results showed little variation in the levels of labile organic carbon between the profiles but a large variation in total carbon and nitrogen levels, especially in the Organossolo Fólico Hêmico lítico profile. The ratios between the carbon and nitrogen of humic acids and fulvic acids (means of HAC/FAC = 1.61 and AHN/FACN = 1.05), carbon and nitrogen of the alkaline extract and humin (means of AEC/HUMC = 0.71 and AEN/HUMN = 0.38), carbon and nitrogen of the alkaline extract, and total carbon and total nitrogen (means of AEC/TC = 0.28 and AEN/TN = 0.19) were effective in determining the humification level of the profiles. This study proposes that the attributes evaluated, especially the ratio between the carbon of the alkaline extract of the humic substances (carbon of the fulvic acid fraction + carbon of the humic acid fraction) and the total soil carbon, as well as the ratio between the C and N of the humin fraction, should be used to define lower categorical levels of Organossolos. This new approach could facilitate the classification of these soils and contribute to a better understanding of the composition of Organossolos in Brazil. SiBCS (SiBCS Histosols (Histosols genesis SOM. . (SOM) regions 1 Park RJ obtained profile means HACFAC HAC FAC 161 61 1.6 AHNFACN AHN FACN 1.05, 105 1.05 , 05 1.05) AECHUMC AEC HUMC 071 0 71 0.7 AENHUMN AEN HUMN 0.38, 038 0.38 38 0.38) AECTC TC 028 28 0.2 AENTN TN 0.19 019 19 evaluated Brazil (SOM 6 1. 10 1.0 07 7 0. 03 0.3 3 02 2 0.1 01

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 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

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 State parks are integral protection units created to protect ecosystems. However, anthropic activities may have been previously performed before their creation, forming transitional areas. Studies that evaluate the modifications of edaphic properties in these environments are scarce. The aim of this study was to evaluate the changes in soil properties and litter stock in areas of eucalyptus-forest ecotones. Litter stock (Stocklitter) and total soil organic carbon content and stock (TOCsoil), weighted mean diameter (MWD), origin of aggregates (biogenic or physicogenic) and respective content of total organic carbon (TOCBio and TOCPhy), total organic carbon (TOCAG), soil organic matter chemical fractions [fulvic acid (FAC), humic (HAC), and humin (HUMC)], and particulate, mineral-associated, free light and intra-aggregate light (POC, MAOC, FLFC, and ILFC) soil organic matter, fertility, and glomalin-related soil protein (GRSP) fractions were evaluated in aggregates (layer 0.00-0.10 m) in areas of eucalyptus-forest ecotone (Eco), preserved forest fragment (For), and eucalyptus plantation (Euc), in Nova Baden State Park, Lambari–MG. In the Euc and Eco areas, the highest Stocklitter content was found. Higher values of TOCsoil, TOCAG, GRSP, and MWD were observed in the Euc area. In the biogenic aggregates, the highest content of TOCBio, HAC, HUMC, POC, MAOC, FLFC, and ILFC was determined in detriment of the physicogenic ones. The dynamics of edaphic properties in the Eco area showed greater similarity with the For area than in the Euc area. In general, all vegetation covers contribute to the maintenance of soil quality. ecosystems However creation scarce eucalyptusforest ecotones (Stocklitter TOCsoil , (TOCsoil) MWD, (MWD) TOCBio TOCPhy, TOCPhy TOCPhy) TOCAG (TOCAG) fulvic FAC, FAC (FAC) HAC (HAC) HUMC (HUMC)] particulate mineralassociated, mineralassociated mineral associated, associated mineral-associated intraaggregate intra aggregate POC (POC MAOC FLFC fertility glomalinrelated glomalin related GRSP (GRSP layer 0.000.10 000010 0.00 0.10 0 00 10 0.00-0.1 m Eco, (Eco) For, (For) Euc, (Euc) Park LambariMG Lambari MG Lambari–MG found ones general quality (TOCsoil (MWD (TOCAG (FAC (HAC (HUMC) 000 0.000.1 00001 0.0 010 0.1 1 0.00-0. (Eco (For (Euc (HUMC 0.000. 0000 0. 01 0.00-0 0.000 0.00-

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