Litter Decomposition of Xaraes-Grass Pasture Subjected to Different Post-Grazing Residuals

Since fertilizers are used less extensively on Xaraes-grass (Brachiaria brizantha) pastures in Brazil because of costs, the main route of nitrogen (N) supply to plants is through nutrient recycling via litter decomposition. One of the strategies used to maintain the supply of N is to manage the pasture correctly by keeping it under grazing pressure so that the amount of recycled nutrients in the residue is sufficient to meet the pasture requirements (Jantalia et al.2006). Thus, the aim of this study was to evaluate different residual leaf area indices (RLAI) and determine which one provides the best restoration of pasture leaf area index and nutrient cycling

Dinâmica de carbono e nitrogênio em pastos de capim-xaraés submetidos a diferentes resíduos pós-pastejo

O índice de área foliar residual (IAFr) é importante ferramenta no manejo das pastagens, mas pouco se sabe sobre sua influência nas características físicas, químicas e biológicas do solo, além da contribuição para os estoques de carbono e nitrogênio do solo. O experimento teve por objetivo quantificar o estoque de carbono e nitrogênio, a emissão de CO2 e a decomposição da serrapilheira de pastos de capim-xaraés submetidos a diferentes resíduos pós- pastejo nas condições edafoclimáticas de Jaboticabal, SP. A área total de capim-xaraés era de 2.795,9 m², formada em dezembro de 2004 e foi dividida em 12 piquetes para alocação do experimento. Os tratamentos consistiram de quatro resíduos póspastejo, definidos por índice de área foliar residual (IAFr = 0,8; 1,3; 1;8 e 2,3). O IAFr foi estimado com auxílio do aparelho analisador de dossel – AccuPAR Linear PAR/LAI ceptometer da Decagon. A entrada dos animais nos piquetes de pastejo ocorreu quando o dossel atingiu 95% de interceptação de luz (IL) e a saída sempre que o IAFr pré determinado fosse atingido. As avaliações de estoque de carbono e nitrogênio no solo foram realizadas na profundidade de 0 a 30 cm, com três repetições em cada área. Os estoques de carbono e nitrogênio foram calculados com base na massa de solo equivalente. As medidas de emissão de CO2 foram realizadas semanalmente utilizando-se o aparelho de câmara de fluxo LI-COR (LI- 8100). As avaliações das atividades enzimáticas do solo foram feitas a cada 30 dias na profundidade de 0-20 cm durante os meses de janeiro a outubro de 2011, e nestas amostras, foram realizadas as determinações da: atividade das proteases, arilsulfatases, celulases e desidrogenases. A avaliação da decomposição da serrapilheira seguiu a técnica de sacos de “nylon”, sendo incubados por 0, 4, 8, 16, 32, 64, 128 e 256 dias...Residual leaf area index (LAIr) is an important tool in pasture management, but little is known about its influence on physical, chemical and biological soil properties, in addition to the contribution to carbon and nitrogen stocks in the soil. The experiment aimed to quantify carbon and nitrogen stocks in the soil, CO2 emissions and litter decomposition in Xaraés grass pastures under different post-grazing residues in environmental conditions of Jaboticabal, SP. Total area of Xaraés grass was 2795,9 m², formed in December 2004 and was divided into 12 paddocks for experiment allocation. The treatments consisted of four post-grazing residues, defined by residual leaf area index (LAIr = 0,8, 1,3, 1,8 and 2,3). LAIr was estimated with aid of canopy analyzer equipment - AccuPAR Linear PAR / LAI ceptometer the Decagon. The animals starting grazing in the paddocks when the canopy reached 95% light interception (LI) and the end of grazing occurred when the LAIr predetermined was reached. Evaluations of carbon and nitrogen stocks in soil were realized at depth 0 to 30 cm, with three replications in each area. Carbon and nitrogen stock were calculated based on the equivalent soil mass. Measurements of CO2 emissions were performed weekly using an equipment flow chamber LI-COR (LI-8100). Evaluations of soil enzymatic activities were made every 30 days at a depth of 0-20 cm during ten months (January to October 2011), and these samples were analyzed: proteases, arylsulfatases, cellulases and dehydrogenases activity. Evaluation of litter decomposition followed the litter bag technique and incubated for 0, 4, 8, 16, 32, 64, 128 and 256 days. Dry matter (DM), organic matter (OM), nitrogen (N), phosphorus (P) and carbon (C) contents was determined and calculated the C: N ratio in the remaining material. Soil C and N contents, soil C: N ratio, and C and N stocks in the soil were different... (Complete abstract click electronic access below

Acúmulo e desaparecimento de forragem e variações na estrutura de pastos de capim-xaraés submetidos a intensidades de pastejo em lotação intermitente

The aim of this study was to evaluate the effects of residual leaf area index (rLAI), years of evaluation and grazing cycles on the accumulation and disappearance of forage, and changes in the pasture structure of xaraes palisadegrass submitted to grazing intensities and intermittent stocking in two summers. The experiment was carried out at the Faculdade de Ciencias Agrarias e Veterinaria of Unesp, Campus of Jaboticabal, SP and the intensities of grazing were defined by four rLAI: 0.8, 1.3, 1.8 and 2.3. When the canopy intercepted 95% of incident light, the animals were placed on the pasture for grazing and kept until the rLAI target has been reached. Pastures were grazed by non-lactating Holstein cows (Bos Taurus Taurus L.), using the technique of mob-stocking. It was evaluated the canopy height, accumulation, disappearance and morphological components of forage and rest period. Residual leaf area index from 1.3 to 1.8 are the best in the accumulation and disappearance of forage and pasture structure. It is observed variability of the accumulation and disappearance of forage and pasture structure for years of assessment and grazing cycles within each year

Características morfogênicas e estruturais do capim-xaraés submetido a intesidades de pastejo

The aim of this study was to evaluate the effects of residual leaf area index (rLAI), years of evaluation and grazing cycles on the morphogenetic and structural characteristics of xaraés palisadegrass subjected to grazing intensities in two summers (years of evaluation). The experiment was carried out at the Universidade Estadual Paulista Júlio de Mesquita Filho - UNESP, Campus de Jaboticabal, São Paulo, Brasil and the intensities of grazing were defined by four rLAI: 0.8, 1.3, 1.8 and 2.3. When the canopy intercepted 95% of incident light, the animals were placed on the pasture for grazing and kept until the rLAI target has been reached. Pastures were grazed by non-lactating Holstein cows (Bos Taurus Taurus L.), using the technique of mob-stocking. The morphogenetic and structural characteristics of xaraés palisadegrass respond effectively to weather conditions. There is variability in morphogenetic and structural characteristics in response to years and grazing cycles within years

Agronomic and chemical characteristics of hybrid corn to ensiling

Our aim was to evaluate agronomic and chemical characteristics of corn hybrids to ensiling. It were evaluated nine corn hybrids (MX 300, RB 9308, 2B655, XB 6012, GNZ 2500, PL6890, PRE 32D10, PRE 22T10 e AG 1051), with three replicates. The higher fresh matter yield were observed in the hybrids PL6890 and PRE 32D10, while the dry matter yield was observed in the hybrid PRE 32D10 (13.43 t ha(-1)). The hybrids PRE 32D10 and PRE 22T10 stood out to present higher percent of leaf in relation to whole plant, while the lower percent of stems was found in the hybrids MX 300, 2B655 and XB 6012, however the higher leaves: stems relation was found in XB 6012 (0.49). There was higher CP content in the hybrid PRE 32D10 (9.10% of DM), while the lower NDF (57.78% of DM) and cellulose content (24.27% of DM) were observed in the hybrid GNZ 2500. The hybrid PL6890 presented higher ADF and lignin contents, the others hybrids had values lower. The lower NDIN content was observed in the hybrid RB 9308, while the lower AIDN content occurred on the hybrid 2B655. The lower buffer capacity was observed in the hybrid 2B655 (0.29). There are some differences on chemical composition among the corn hybrids used in this study, however, it is recommended to use the hybrids MX 300, PL6890 and PRE 32D10 for showing higher dry matter yield, which may reflect in the amortization of silage production costs.Our aim was to evaluate agronomic and chemical characteristics of corn hybrids to ensiling. It were evaluated nine corn hybrids (MX 300, RB 9308, 2B655, XB 6012, GNZ 2500, PL6890, PRE 32D10, PRE 22T10 e AG 1051), with three replicates. The higher fresh matter yield were observed in the hybrids PL6890 and PRE 32D10, while the dry matter yield was observed in the hybrid PRE 32D10 (13.43 t ha-1). The hybrids PRE 32D10 and PRE 22T10 stood out to present higher percent of leaf in relation to whole plant, while the lower percent of stems was found in the hybrids MX 300, 2B655 and XB 6012, however the higher leaves: stems relation was found in XB 6012 (0.49). There was higher CP content in the hybrid PRE 32D10 (9.10% of DM), while the lower NDF (57.78% of DM) and cellulose content (24.27% of DM) were observed in the hybrid GNZ 2500. The hybrid PL6890 presented higher ADF and lignin contents, the others hybrids had values lower. The lower NDIN content was observed in the hybrid RB 9308, while the lower AIDN content occurred on the hybrid 2B655. The lower buffer capacity was observed in the hybrid 2B655 (0.29). There are some differences on chemical composition among the corn hybrids used in this study, however, it is recommended to use the hybrids MX 300, PL6890 and PRE 32D10 for showing higher dry matter yield, which may reflect in the amortization of silage production costs.Objetivou-se avaliar as características agronômicas e químico-bromatológicas de híbridos de milho para ensilagem. Os tratamentos avaliados foram nove híbridos de milho (MX 300, RB 9308, 2B655, XB 6012, GNZ 2500, PL6890, PRE 32D10, PRE 22T10 e AG 1051), com três repetições. As maiores produções de MV foram verificadas nos híbridos PL6890 e PRE 32D10, enquanto a maior produção de MS foi observada no híbrido PRE 32D10 (13,43 t ha-1). Os híbridos PRE 32D10 e PRE 22T10 destacaram-se por apresentarem maior porcentagem de lâminas foliares em relação à planta inteira, enquanto a menor porcentagem de colmos foi encontrada nos híbridos MX 300, 2B655 e XB 6012, entretanto a maior relação folha:colmo foi verificada no híbrido XB 6012 (0,49). Observou-se maior teor de PB no híbrido PRE 32D10 (9,10% da MS), enquanto o menor teor de FDN (57,78% da MS) e celulose (24,27% da MS) foram verificados no híbrido GNZ 2500. O híbrido PL6890 apresentou maior teor de FDA (39,20 % da MS) e lignina (8,63% da MS), os demais híbridos apresentaram valores inferiores. Verificou-se menor N retido na FDN (NIDN) no híbrido RB 9308, enquanto a menor retenção de N em FDA (NIDA) ocorreu no híbrido 2B655. A menor capacidade tampão (CT) foi verificada no híbrido 2B655 (0,29). Embora haja diferenças na composição químico-bromatológica dos híbridos de milho avaliados neste estudo, recomenda-se utilizar os híbridos MX 300, PL6890 e PRE 32D10 por apresentarem produção de matéria seca mais elevada, os quais podem refletir na amortização dos custos na produção das silagens

Espécies de plantas do banco de germoplasma forrageiro da FCAV/UNESP Jaboticabal

The choice of forage species is extremely important to animal production systems implementation. Germplasm collection from the Forage and Pastures sector at Agriculture and Veterinary Sciences College, UNESP, Jaboticabal, this germplasm collection aims to preserve and disclose the plant species used in animal feeding or green fertilization. Germplasm collection is currently composed of 99 sites covering an area of approximately 0.6 hectares. Germplasm collection includes 69 grass species, 29 legumes species and only one species of cactaceae family. Germplasm collection is used for teaching, research, exchange of materials and disclosure for farmer and others educational meanings.A escolha da espécie forrageira é de extrema importância na implantação de um sistema de produção animal a pasto. O banco de germoplasma do Setor de Forragicultura e Pastagens da Faculdade de Ciências Agrárias e Veterinárias, UNESP, Câmpus de Jaboticabal, tem como objetivo preservar e difundir as espécies de plantas que podem ser utilizadas na alimentação animal ou em adubação verde. O banco atualmente é composto por 99 canteiros que ocupam uma área de aproximadamente 0,6 hectares. A coleção conta com 69 espécies de gramíneas, 29 espécies de leguminosas e uma espécie da família cactaceae. O banco é utilizado para aulas práticas, pesquisas, intercâmbio com outras instituições e divulgação do banco para produtores

Consorciação, uma alternativa de manejo de pastagens e de melhoria do meio ambiente

Consortium is a way to add grass and legumes species in the same area of cultivation. This method can decrease costs in nitrogen fertilization by nitrogen fixation, pastures ecosystem diversification and improving the nutritional characteristics of forage produced among other benefits. Implementation of this project used Marandu palisade grass and a legume (Arachis pintoi cv. Amarillo). This project aim to determine an appropriate management for the successful establishment of legumes in consortium with grass in pastures and to detect the mitigation capacity of greenhouse gases mitigation by the system.A consorciação de pastagens é uma maneira de agregar em uma mesma área espécies de gramíneas e leguminosas forrageiras. Com a utilização deste método podemos obter: vários benefícios: economia nos gastos com adubação nitrogenada através da fixação biológica de nitrogênio, diversificação do ecossistema de pastagens e melhoria nas características nutricionais da forragem produzida entre outros benefícios. Na implantação deste projeto foi utilizada capim Marandu e uma leguminosa (Arachis pintoi). O projeto tem como principal objetivo determinar o manejo mais apropriado para o sucesso do estabelecimento de leguminosas em consórcio com gramíneas em pastagens, além de demonstrar a capacidade de mitigação de gases de efeito estufa pelo sistema