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ABSTRACT:Green manures are an alternative for substituting or supplementing mineral nitrogen fertilizers. The aim of this study was to quantify biological N fixation (BNF) and the N contribution derived from BNF (N-BNF) to N levels in leaves of coffee intercropped with legumes grown on four family farms located in the mountainous region of the Atlantic Forest Biome in the state of Minas Gerais, Brazil. The following green manures were evaluated: pinto peanuts (Arachis pintoi), calopo (Calopogonium mucunoides), crotalaria (Crotalaria spectabilis), Brazilian stylo (Stylosanthes guianensis), pigeon pea (Cajanus cajan), lablab beans (Dolichos lablab), and velvet beans (Stizolobium deeringianum), and spontaneous plants. The experimental design was randomized blocks with a 4 × 8 factorial arrangement (four agricultural properties and eight green manures), and four replications. One hundred grams of fresh matter of each green manure plant were dried in an oven to obtain the dry matter. We then performed chemical and biochemical characterizations and determined the levels of

The objective of this study was to evaluate sediment, water and nutrient losses from different pasture managements in the Atlantic Rainforest biome. A field study was carried out in Alegre Espiríto Santo, Brazil, on a Xanthic Ferralsol cultivated with braquiaria (Brachiaria brizantha). The six pasture managements studied were: control (CON), chisel (CHI), fertilizer (FER), burned (BUR), plowing and harrowing (PH), and integrated crop-livestock (iCL). Runoff and sediment samples were collected and analyzed for calcium (Ca), magnesium (Mg), potassium (K), phosphorus (P) and organic carbon contents. Soil physical attributes and above and below biomass were also evaluated. The results indicated that higher water loss was observed for iCL (129.90mm) and CON (123.25mm) managements, and the sediment losses were higher for CON (10.24tha) and BUR (5.20tha) managements when compared to the other managements. Majority of the nutrients losses occurred in dissolved fraction (99% of Ca, 99% of Mg, 96% of K, and 65% of P), whereas a significant fraction of organic carbon (80%) loss occurred in a particulate form. Except for P, other nutrients (Ca, Mg and K) and organic carbon losses were higher in coarse sediment compared to fine sediment. The greater losses of sediment, organic carbon, and nutrients were observed for CON followed by BUR management (p<0.05). Our findings indicated that the traditional pasture management adopted in the Atlantic Rainforest needs to be rethought and burned management should be avoided. Based on the water, soil, and nutrient losses from various practices, to reduce pasture degradation, farmers should adopt edaphic practices by applying lime and fertilize to improve pasture growth and soil cover, and reducing soil erosion in the hilly Brazilian Atlantic Rainforest biome.

The pedogenesis of a latosol – plinthic podzolic latosol - hydromorphic quartzous sand sequence wasstudied, with respect to its chemical, physical and mineralogical properties. These soils are developed fromcrystalline substratum of the Guiana Complex, in the Occidental Amazon. The studied area is located inthe Waimiri-Atroari Indigenous reserve, at the Km 160 of the BR 174, which links Manaus to Caracaraí.The toposequence represents a hill formed by clayey soils in the top of the landscape, ending in a broadvalley flat with sandy soils in the bottom, under strong hydromorphism. The temperature and moistureregime of the soils are isohypertermic to hyperthermic, and udic to aquic, from the higher parts to the valleybottom, respectively. Six trenches were open and described in detail; in addition, core samples wereexaminated in six extra sites.Four soil profiles representatives of the segments ( latosolic, transition and hidromorphic) were selectedfor the study of physical , chemical, mineralogical and micromorphological characteristics of theircomponents. The higher part of the sequence is dominated by red-yellow latosol, the transition segment byplinthic podzolic intergrade to red-yellow latosol, and the lower parts by hidromorphic quartzous sand. Theparent material of the soil of all the sequence is heterogeneous, but basically derived from wheatheredgranitic rock, with some localized influence of alteration products of mafic rocks. All soils have a highaluminum saturation. In the higher parts of the sequence the textural gradient is lower and the clay fractionis dominated by kaolinite and crystalline iron oxides. Downslope the textural gradient increases and theiron forms are less crystalline. At the valley bottom rests a deep sandy mantle, where iron oxides are absent,remaining traces of kaolinite. Mica/illite were found in the deeper parts of the soils and hydroxide-interlayeredvermiculite in the upper parts. The sequence of evolution is processed mainly by pedological transformationinvolving seasonal acid and hydromorphic conditions, where ferrolysis occurs. This process leads to alateral degradation of the latosolic material of the top of the landscape, with clay destruction and concentrationof sandy materials dominated by quartz. Micropedological features related to the ferrolysis process arepresented and discussed.

Intensive land use can lead to a loss of soil physical quality with negative impacts on soil aggregates, resistance to root penetration, porosity, and bulk density. Organic and agroforestry management systems can represent sustainable, well-balanced alternatives in the agroecosystem for promoting a greater input of organic matter than the conventional system. Based on the hypothesis that an increased input of organic matter improves soil physical quality, this study aimed to evaluate the impact of coffee production systems on soil physical properties in two Red-Yellow Oxisols (Latossolos Vermelho-Amarelos) in the region of Caparaó, Espirito Santo, Brazil. On Farm 1, we evaluated the following systems: primary forest (Pf1), organic coffee (Org1) and conventional coffee (Con1). On Farm 2, we evaluated: secondary forest (Sf2), organic coffee intercropped with inga (Org/In2), organic coffee intercropped with leucaena and inga (Org/In/Le2), organic coffee intercropped with cedar (Org/Ced2) and unshaded conventional coffee (Con2). Soil samples were collected under the tree canopy from the 0-10, 10-20 and 20-40 cm soil layers. Under organic and agroforestry coffee management, soil aggregation was higher than under conventional coffee. In the agroforestry system, the degree of soil flocculation was 24 % higher, soil moisture was 80 % higher, and soil resistance to penetration was lower than in soil under conventional coffee management. The macroaggregates in the organic systems, Org/In2, Org/In/Le2, and Org/Ced2 contained, on average, 29.1, 40.1 and 34.7 g kg-1 organic carbon, respectively. These levels are higher than those found in the unshaded conventional system (Con2), with 20.2 g kg-1.

Corretivos da acidez do solo e níveis de umidade no desenvolvimento da cana-de-açúcar 1 RES UMO A cana-de-açúcar (Saccharum spp.) é uma cultura bastante disseminada por todo território brasileiro devido ao seu fácil cultivo e seus múltiplos usos como a produção de açúcar, álcool e alimentação animal. Para que sua produção seja satisfatória, deve ser adequada a combinação de fatores como umidade e correção da acidez do solo. Este trabalho teve como objetivo avaliar o uso dos corretivos calcário e escória, em três níveis de umidade no solo, na produção de matéria seca da parte aérea, das folhas, do colmo, da raiz e o número de colmos da cana-de-açúcar. Foram avaliados cinco níveis dos corretivos calcário e escória de siderurgia, de modo que a saturação por bases (V%) permanecesse após incubação com: N 1 (testemunha, V = 21,4%), N 2 (V = 40%); N 3 (V = 60%); N 4 (V = 80%) e N 5 (V = 100%). A incubação foi realizada em sacos plásticos por 21 dias, com umidade próxima a 70%. Após 150 dias de cultivo, procedeu-se a contagem do número de colmos (NC) e o corte da parte aérea, separando-se o colmo das folhas, determinando-se a matéria seca da parte aérea (MSPA), matéria seca da folha (MSF), matéria seca do colmo (MSC) matéria seca das raízes (MSR). O uso de corretivos da acidez do solo, níveis de água e níveis de saturação por bases influenciam o desenvolvimento e nutrição mineral da cana-de-açúcar. Para os menores níveis de água no solo (60 e 80%CC), a escória promoveu maior produção de matéria seca da parte aérea da cana-de-açúcar, em relação ao calcário. O aumento da saturação por bases com a aplicação de doses crescentes de calcário e escória incrementaram a produção de matéria seca da parte aérea, folhas, caule e raízes da cana-de-açúcar. Palavras-chave: escória, calcário, matéria seca Correctives of the acidity of the soil and levels of humidity in the development and nutrition of the sugarcane AB S TR ACT Sugar caner (Saccharum spp.) cultivation is quite disseminated throughout Brazilian territory due to its easy cultivation and its multiple uses such as sugar and alcohol yield and animal feeding. In order to have a satisfactory yield, the combination of factors such as humidity and soil acidity correction should be corrected. This work had the objective of evaluating use of correctives (limestone and slag) in three levels of soil humidity, dry matter yield of shoot, culm, root and culm number of plant. Five levels of limestone and metallurgy slag corrective were evaluated, so that saturation by bases (V%) remained after incubation with: N 1 (control, V = 21.4%), N 2 (V = 40%); N 3 (V = 60%); N 4 (V = 80%) and N 5 (V = 100%). Incubation was carried out in plastic sacks for 21 days, with humidity close to 70%. After 150 days of cultivation, counting of culm (CC) and cut of shoot were carried out by separating culm from leaves, determining dry matter of shoot (DMAP), dry matter of leaf (DML), dry matter of culm (DMC) dry matter of root (DMR). Usage of soil acidity correctives, level of water and level of saturation b...

RESUMOO processo de decomposição de serapilheira deve ser amplamente estudado por se tratar de um fator-chave na manutenção e ciclagem de nutrientes nos ecossistemas. Este estudo teve como objetivos: avaliar a decomposição, a liberação de nutrientes e a atividade microbiana da serapilheira em coberturas florestais de floresta secundária, Acacia mangium, Sapindus saponaria e Hevea brasiliensis, no sul do Espírito Santo. A decomposição da serapilheira e a liberação de nutrientes foi quantificada por meio de litter bags. Para a avaliação da atividade microbiana procedeu-se à quantificação do carbono mineralizável por meio da evolução de CO 2 . Os resultados mostraram que as coberturas florestais se comportaram de forma diferenciada quanto à decomposição e atividade microbiana, destacando-se a Sapindus saponaria, que apresentou maior velocidade de decomposição de serapilheira. A cobertura de Sapindus saponaria apresentou quantidades acumuladas de CO 2 superiores às demais. A cobertura de Acacia mangium apresentou os menores valores de CO 2 acumulado.Palavras-chave: ecossistema florestal, ciclagem de nutrientes, microrganismo. Decomposition and Microbial Activity of Forest Floor Litter in the South of Espírito Santo ABSTRACTThe decomposition process of litter should be widely studied, as it is a key factor for nutrient maintenance and cycling in ecosystems. This study aimed to evaluate the decomposition, release of nutrients, and microbial activity of the forest floor litter of secondary forest, Acacia mangium, Sapindus saponaria, and Hevea brasiliensis in the south of Espirito Santo. The litter decomposition and nutrients release was measured by means of litter bags added to each forest cover. For the assessment of microbial activity, we quantified mineralizable carbon by CO 2 evolution. The results showed that the forest covers behaved differently in terms of decomposition and microbial activity; particular emphasis is given to Sapindus saponaria, which presented a faster decomposition of litter. The cover of Sapindus saponaria also presented higher amounts of accumulated CO 2 compared to other forest covers; whereas the cover of Acacia mangium presented the lowest values of accumulated CO 2 .