Composição química e velocidade de decomposição de plantas visando a adubação verde

Productive systems in which green manure is the source of nutrients must develop more efficient ways to improve soil nutrient dynamics. A well-synchronized balance must be established between specific crop demands and supply of nutrients from decomposition. However, scientific data and information to help improve green manure management in Brazil is still insufficient. For that reason, a number of arboreal species was first chemically characterized and then subjected to decomposition analysis in order to establish a correlation between some parameters. Species were grouped together based on the similarity of chemical composition and decomposition rate. The lignin:N and (lignin+polyphenol):N ratios were found to have the greatest correlation coefficient with the dry matter decomposition rate and nitrogen release.Sistemas produtivos que utilizam a adubação verde prezam por uma dinâmica mais eficiente de nutrientes no solo. Nesse sentido, é importante buscar a sincronia entre a demanda nutricional da cultura e a disponibilidade de nutrientes provenientes da decomposição. Esse estudo objetivou estabelecer uma correlação entre a composição química e a velocidade de decomposição de espécies em um sistema agroflorestal. Para tanto, realizou-se a caracterização química de espécies arbóreas, seguida de estudos de decomposição e busca de correlação entre os parâmetros analisados. De posse dos resultados, foi possível agrupar espécies com composição química e taxas de decomposição semelhantes. As relações lignina:N e (lignina+polifenol):N apresentaram os maiores coeficientes de correlação com a velocidade de decomposição de massa seca e liberação de nitrogênio

Effect of Carnaúba Bagana Mulching on Tree Species Planted in Degraded Areas in Caatinga

Abstract Experimental trials were conducted to evaluate the effectiveness of mulching with carnauba bagana, a by-product of wax extraction from Copernicia prunifera leaves, on the establishment of 32 shrub and tree species in the Caatinga region. The evaluations were made in areas degraded by mining and embankment of piçarra. Treated plants received 10 L of carnauba mulch in the crown of planted seedlings, while control plants received no mulch. After 24 months, mulching of carnauba improved the growth or survival of eight of the 32 species, while worsening that of two species. Specifically, mulching increased (p<0.05) the survival of Pseudobombax marginatum and Peltophorum dubium, and the height and canopy area of Anadenanthera colubrina, Bauhinia cheilantha, Copernicia prunifera, Hymenaea courbaril, Mimosa caesalpiniifolia and Senna spectabilis. The results demonstrate that the carnauba-based mulch can be directed to the species that responded positively, with the goal of improving establishment and growth in degraded areas of the region

INFLUENCE OF Urochloa brizantha ON THE GROWTH AND NUTRITIONAL ABSORPTION OF TREE SPECIES

Influence of Urochloa brizantha on the growth and nutritional absorption of tree species. The objective of this study was to evaluate the influence of Urochloa brizantha var. Marandu on the growth and accumulation of macronutrients in the leaves of Cordia trichotoma and Guarea guidonia. Seedlings of tree species were transplanted to 18-liter pots and kept free of U. brizantha for three months. After that period, three treatments were adopted that consisted of the control (T0), two plants of U. brizantha per pot (T2) and four plants of U. brizantha per pot (T4). Growth and nutrient accumulation of tree species were evaluated after 84 days of coexistence with U. brizantha. The increment in diameter, of both tree species, leaf area and shoot dry matter of G. guidonia were significantly affected by the presence of U. brizantha, compared to the control. Significant differences were observed for the accumulation of potassium and magnesium in the leaves of C. trichotoma.

Efeito de leguminosa arbórea na nutrição nitrogenada do cafeeiro (Coffea canephora Pierre ex Froehn) consorciado com bananeira em sistema orgânico de produção

Coffee is a crop with high economical importance to Brazil. It is cultivated on about 2,4 millions hectares spread in almost all the country. Nitrogen fertilizers are routinely used by coffee growers and alternatives to reduce their applications are important. In this study, coffee plants (Coffea canephora Pierre ex Froehn) intercroped with gliric&iacute;dia (Gliricidia sepium (Jacq.) Steud.) and banana (Musa paradisiaca L.) and banana alone for shade were evaluated. After pruning of gliricidia, their leaves and branches were analysed for the biomass, decomposition rate and their influence on coffee nitrogen nutrition. Gliricidia demonstrated to be an important source of nitrogen for coffee, since it maintains the leaves above the critical levels, as compared to coffee with banana alone treatment, independently of the pruning process. Gliricidia branches were not an important source of Nitrogen due to their low content in nutrients and slow decomposition rate, reaching only 30% of the total in a period of 6 months, while the half life for leaves was 19 days.O cafeeiro é uma das culturas de maior importância econômica para o Brasil, sendo cultivado em cerca de 2,4 milhões de hectares. O uso de fertilizantes, entre eles o nitrogenado, é bastante difundido. Alternativas que possam reduzir a necessidade de aplicação deste nutriente são importantes. Neste estudo avaliou-se o efeito do cultivo do cafeeiro (Coffea canephora Pierre ex Froehn) sombreado com Gliricidia sepium (Jacq.) Steud. e bananeira (Musa paradisíaca L.), em comparação com o café crescendo somente com a bananeira. Foram determinados, após a poda da gliricidia, a biomassa e a taxa de decomposição de folhas e ramos, e suas influências na nutrição nitrogenada do cafeeiro. A gliricídia se comportou como importante fonte de N para o café, cujos teores em folhas mantiveram-se acima do nível crítico, quando comparado ao café cultivado somente com a banana, independentemente da realização de podas. Os ramos da gliricídia tiveram pouca importância como fertilizante, devido ao seu baixo conteúdo de nutrientes e sua baixa taxa de decomposição, que alcançou 30% do total num período de 6 meses, enquanto as folhas apresentaram tempo de meia vida de 19 dias

Weed interference factors that affect the growth of an atlantic forest tree species

The objective of this study was to assess the possible existence of allelopathy and competition for water and nutrients of the grass Urochloa brizantha (Hochst. ex A. Rich.) Stapf cv. Marandu grown together with Schinus terebinthifolius Raddi in a greenhouse. The experimental design was completely randomized in a factorial scheme with 3 factors and the following levels: (1) one individual of the forest species with and without the presence of U. brizantha at a density of 4 individuals per pot; (2) supply of nutrients in limiting or non-limiting dose; and (3) supply of a limiting or non-limiting amount of water. We measured the height and root collar diameter of the tree seedlings, as well as the shoot and root dry weights of both species. There was competition by the grass with the tree species. The coexistence reduced the height by 30.5 cm, the root collar diameter by 1.58 mm and the shoot and root dry weights by 22.7 g and 9.5 g, respectively, of S. terebinthifolius. The greater supply of water in the pots increased the height by 18.9 cm of the S. terebinthifolius seedlings compared to the plants grown with limited water supply. Evidence was also observed of competition for nutrients, principally at the largest nutrient addition level, where the presence of the grass caused an additional decrease in the root collar diameter and shoot dry weight of the tree species, while the shoot and root dry weights of the grass increased. The results did not allow evaluating the existence of allelopathy of U. brizantha on S. terebinthifolius. terebinthifolius

BIOMASSA DE RAÍZES E REGIME HÍDRICO DO SOLO EM PLANTIO DE Pseudosamanea guachapele (Kunth) Harms EM UM PLANOSSOLO HÁPLICO

Root biomass and soil water regime in Pseudosamanea guachapele (Kunth) Harms plantation. This research intended to quantify root biomass and analyze its distribution, as well as soil water regime on a seven years old Pseudosamanea guachapele plantation. The leguminosae tree accumulated in its roots 8.8 kg plant-1 (or 29.5 Mg ha-1) of biomass, 57% in tap root and 43% in lateral thin roots. Thin roots were located preferentially at the first 20 cm underground. Volumetric humidity variations tended to decrease the more the depth. The most evident concentration on depth of water near the trunk indicates possible contribution of rain water flowing through the stem.Biomassa de raízes e regime hídrico do solo em plantio de Pseudosamanea guachapele (Kunth) Harms num Planossolo Háplico. Objetivou-se com este estudo quantificar a biomassa e a distribuição de raízes, bem como o regime hídrico do solo num plantio de Pseudosamanea guachapele com sete anos. A leguminosa acumulou, nas raízes, 8,8 kg árvore-1 (ou 29,5 Mg ha-1) de biomassa seca, sendo que 57% representavam a raiz pivotante e o restante (43%) as raízes mais finas e laterais. Cerca de 70% da massa de raízes mais finas encontravam-se nos 20 primeiros cm de profundidade. As variações na umidade tenderam a se reduzir em profundidade. A maior recarga em profundidade próximo ao tronco da espécie indica possível contribuição do escoamento pelo tronco da água da chuva

CORRELATION BETWEEN THE CARDIORESPIRATORY FITNESS LEVEL AND HABITUAL PHYSICAL ACTIVITY IN BRAZILIAN AIR FORCE RECRUITS

Cardiorespiratory fitness is the ability to maintain moderate or high-intensity efforts for long periods of time and is highly related to physical activity habits and fitness levels. Analyzing habitual physical activity in military personnel and its relationship with cardiorespiratory fitness is consequently fundamental. Thus, the objective of this study was to verify the correlation between the cardiorespiratory fitness level and habitual physical activity in Brazilian Air Force recruits. The sample consisted of 86 recruits in the final phase of the soldier training course. Data was collected using the 12-minute cardiorespiratory fitness test and the Baecke questionnaire validated for the Portuguese language to assess the practice of habitual physical activity. Descriptive statistics were used for sample characterization and exploratory analysis. The distribution of data normality was analyzed using the Shapiro-Wilk test, followed by Pearson’s correlation test and the Mann-Whitney U test to compare the groups with lower and higher cardiorespiratory fitness. The significance level of p ≤ 0.05 was adopted. According to the results, 63.9% of the sample had satisfactory cardiorespiratory fitness levels (good and excellent). No significant correlations were observed between cardiorespiratory fitness and habitual physical activity indices, except for the physical exercise/sports index (p= 0.05). It was found that only the Body Mass Index showed a difference (p= 0.017, Effect Size= 0.637) between the cardiorespiratory fitness groups. It is concluded that most military recruits have adequate cardiorespiratory fitness levels, but these are not influenced by the habitual practice of physical activity.  Article visualizations

O uso de sistemas agroflorestais diversificados na restauração florestal na Mata Atlântica

The Brazilian new environmental law permits the use of agroforestry systems to restore degraded areas protected by legislation, especially in small farms. One question that arises is if it is possible to reduce costs of the restoration process with these agroforestry systems and, at the same time, to offer ecological services, similar to afforestation with the exclusive use of native species of the Atlantic Forest biome. Seeking results to proof the effectivity, an agroforestry system established in 2005, at Seropédica, RJ state, with the objective of connecting two forest fragments, went through a series of evaluations realized on the ecological effectiveness on the connection of these fragments. The results indicated that the quantity and quality of soil fauna and mycorrhizal fungi obtained benefits by the agroforestry system in comparison to the pasture matrix, but are still at lower levels than the forest fragments. Pasture near the agroforestry system has benefited from the environmental improvement there, originated from a “positive edge effect”, a situation quite different from the pasture that was farther from the area of influence of the agroforestry corridor. For the indicators used, the agroforestry system was eficient.Com a nova legislação ambiental brasileira vislumbra-se a possibilidade do uso de sistemas agroflorestais diversificados para recompor áreas de preservação permanente e reserva legal, principalmente em pequenas propriedades rurais. Uma pergunta que surge, diz respeito a capacidade desses sistemas em reduzir custos na restauração florestal e ao mesmo tempo apresentar eficiência ecológica similar aos plantios em que se faz uso exclusivo de espécies nativas do bioma em questão. Buscando a resposta avaliou-se nesse estudo um sistema agroflorestal implantado em 2005, em Seropédica, RJ, que tinha o objetivo de interligar dois fragmentos florestais ali existentes. Desde então foram feitas uma série de avaliações sobre a eficácia ecológica desse “corredor agroflorestal” na interligação desses fragmentos. Os resultados indicaram que a quantidade e a qualidade da fauna do solo e fungos micorrízicos foram favorecidos pelo sistema agroflorestal em comparação à matriz de pastagem, mas ainda se encontram em níveis inferiores aos fragmentos florestais interligados. A pastagem próxima ao sistema agroflorestal vem se beneficiando da melhoria ambiental ali existente, criando um “efeito de borda positivo”, situação bem distinta da pastagem que se encontrava mais distante da área de influência do corredor agroflorestal. Para os indicadores utilizados, o sistema agroflorestal foi eficiente.

Estratégias de controle de braquiárias Urochloa spp. na formação de povoamento para restauração florestal

Forest restoration in pastures dominated by Urochloa spp. (brachiaria) shows relatively high cost, mainly by the difficulty of controlling this weed. The objective of this work was to determine the most efficient brachyria control for forest restoration formation. Four different strategies for brachiaria control in the forest restoration area were compared in the city of Bom Jardim, Rio de Janeiro state: T1 weeding in strips in the planting lines and mowed between the lines; T2 weeding in strips in the planting lines and applications of glyphosate (1.44 kg i.a. ha-1) between the lines; T3 - weeding in total area and consortium with herbaceous legumes nitrogen-fixing; T4 - weeding in strips in the planting lines, mowing and consortium with eucalyptus between the lines. The growth in height, the diameter at ground level and the diameter of the top of ten forest species at different ages were evaluated, as well as all costs involved in the application and maintenance of each treatment, up to 30 months after planting. In every age of valuation, forest plants showed significantly higher average growth in height and diameter at the ground level in the treatment of consortium with herbaceous legumes and application of glyphosate. At 24 months after planting, the top of the trees that were introduced had already covered 80% to 90% of the area of   experimental unit that received the T3 (legumes) and T2 (Glyphosate) treatments, respectively. However, the maintenance cost of the T3 was almost double the T1 units and the cost of the latter was almost three times higher than the units analyzed for T2. As a general rule, eucalyptus consortium between the lines of planting did not harm, but also did not benefit the growth of the native species planted up to 30 months after planting. Chemical control and consortium with herbaceous legumes can be pointed as effective alternatives to control the brachiaria of this area, anticipating the formation of stands and resulting in resource savings.A restauração florestal em áreas de pastagens, dominadas por Urochloa spp. (braquiárias), apresenta custo relativamente elevado, principalmente pela dificuldade de controle dessa planta infestante. O objetivo deste trabalho foi determinar a forma de controle de braquiárias mais eficiente para a formação de povoamento para restauração florestal. Foram comparadas quatro estratégias para controle de braquiária em área de restauração florestal no município de Bom Jardim - RJ: T1 - capina em faixas nas linhas de plantio e roçadas nas entrelinhas; T2 - capina em faixas nas linhas de plantio e aplicações do herbicida glyphosate (1,44 kg i.a. ha-1) nas entrelinhas; T3 - capina em área total e consórcio com leguminosas herbáceas fixadoras de nitrogênio; T4 - capina em faixas nas linhas de plantio, roçadas e consórcio com eucalipto nas entrelinhas. Avaliou-se o crescimento em altura, diâmetro no nível do solo e diâmetro de copa de dez espécies arbóreas em diferentes idades, bem como todos os custos envolvidos na aplicação e manutenção de cada tratamento, até 30 meses após o plantio. Em todas as épocas de avaliação, as plantas florestais apresentaram média de crescimento significativamente superior em altura e em diâmetro nos tratamentos de consórcio com leguminosas e aplicação de glyphosate (T3 e T2). Aos 24 meses após o plantio, a copa das árvores implantadas já recobria 80% a 90% da área da unidade experimental nesses tratamentos. Entretanto, o custo de manutenção do T3 foi quase o dobro das unidades de T1 e o custo deste último foi quase três vezes superior das unidades submetidas a T2. O consórcio de eucalipto nas entrelinhas de plantio não prejudicou, mas não beneficiou o crescimento das espécies nativas. O controle químico e o consórcio com leguminosas herbáceas podem ser apontados como alternativas eficazes para controle da braquiária dessa área, antecipando a formação dos povoamentos e resultando em economia de recursos

DECOMPOSITION OF LEGUME TREE Gliricidia sepium AND Acacia angustissima IN AGROFORESTRY SYSTEMS

Os Sistemas Agroflorestais (SAFs) trazem benef\uedcios m\ufaltiplos e constituem uma alternativa para minimizar a degrada\ue7\ue3o ambiental e alcan\ue7ar um desenvolvimento sustent\ue1vel, devido \ue0 diversidade de esp\ue9cies que os comp\uf5e. O presente estudo avaliou a contribui\ue7\ue3o das leguminosas arb\uf3reas, Gliricidia sepium e Acacia angustissima , cultivadas em aleias intercaladas com banana (Musa sp.) e a\ue7a\ued ( Euterpe oleraceae ), na implanta\ue7\ue3o de Sistema Agroflorestal. Comparou-se a produ\ue7\ue3o de biomassa e ciclagem de nutrientes no SAF, com a leguminosa herb\ue1cea Pueraria phaseoloides e aduba\ue7\ue3o nitrogenada. O SAF foi implantado em maio de 2004, no Campo Experimental da Embrapa Agrobiologia, em Serop\ue9dica - RJ. O delineamento experimental foi de blocos casualizados com cinco tratamentos, constitu\ueddos das leguminosas ac\ue1cia-angust\uedssima (Acacia angustissima), kudzu-tropical ( Pueraria phaseoloides, gliric\ueddia (Gliricidia sepium) dispostas nas entrelinhas da banana e do a\ue7a\ued; al\ue9m de aduba\ue7\ue3o nitrogenada com ureia, e cobertura viva oriunda da vegeta\ue7\ue3o espont\ue2nea. Para quantificar a produ\ue7\ue3o de biomassa e libera\ue7\ue3o de N, P, Ca, Mg e K in situ foram cortadas as leguminosas e ro\ue7ado o kudzu-tropical e a vegeta\ue7\ue3o espont\ue2nea. As determina\ue7\uf5es da mat\ue9ria seca remanescente, libera\ue7\ue3o de nutrientes, constantes de decomposi\ue7\ue3o e os tempos de meia-vida dos res\uedduos vegetais foram realizadas acondicionando-se 50 g de material fresco em litterbags, dispostos na superf\uedcie do solo, tomando-se amostras aos 0, 5, 10, 15, 20, 25, 30, 40, 60 e 75 ap\uf3s o in\uedcio do experimento. Acacia angustissima e kudzu-tropical apresentaram maior produ\ue7\ue3o de biomassa seca, igual a 10,8 Mg ha-1. Os res\uedduos da gliric\ueddia resultaram em maiores constantes de decomposi\ue7\ue3o, nas duas esta\ue7\uf5es do ano.The Agroforestry Systems (SAFs) bring multiple benefits and they are an alternative to minimize environmental degradation, and to achieve a sustainable development, due to greatest diversity of species. This study evaluated the contribution of the leguminous trees, Gliric\ueddia sepium and Acacia angustissima , grown in alley cropping of banana (Musa sp.) and \u201ca\ue7a\ued\u201d palm ( Euterpe oleraceae ) used as green manure in the implantation of an Agroforestry Systems. They were compared the production of biomass, nutrients cycling, nitrogen intake, activity and diversity of soil fauna, and banana productivity in the SAF, and with the usage of the legume Pueraria phaseoloides and nitrogen fertilization. The SAF implantation occurred in May 2004, at the Research Center of Embrapa Agrobiologia, in Serop\ue9dica, Rio de Janeiro State. The following year it was planted the forest African mahogany specie ( Kaya senegalensis ), at the centre of the legumes alleys. The experimental design was of randomized blocks with five treatments and four repetitions. The treatments consisted of the leguminous trees arranged between the lines of bananas and the \u201ca\ue7a\ued\u201d palm, and they were: acacia angust\uedssima (Acacia angustissima), tropical kudzu (Pueraria phaseoloides), and gliric\ueddia (Gliric\ueddia sepium); besides application of nitrogen as urea and spontaneous vegetation. To quantify the production of biomass, and the release of N, P, Ca, Mg and K, the legumes branches were cut and the kudzu tropical and spontaneous vegetation were mowed, in the rainy and dry seasons. The determination of remaining dry matter, releasing of nutrients, decomposition rates, and half life time of plant residues were held to 50 grams of fresh material from litterbags, placed on the soil surface, sampled at 0, 5, 10, 15, 20, 25, 30, 40, 60 and 75 days after the installation of the experiment. Acacia angustissima and kudzu tropical showed higher dry biomass, 9.5 and 10.8 Mg ha-1, respectively. The gliric\ueddia residues showed the highest decomposition rates, in the two year seasons