Elephant grass treated with alkali Capim-elefante tratado com compostos alcalinos

The objective was determine dry matter (DM), crude protein (CD), neutral detergent fiber (NDF), acid detergent (ADF), cellulose, hemicellulose, lignin, ash and digestibility of elephant grass, in advanced maturation stage, submitted to the application of alkali compounds with calcium oxide (CaO), sodium hydroxide (NaOH) and CaO+NaOH, in two periods of treatment. The experiment was conducted according to a project of subdivided parcels that had been constituted by the controlled treatments, 3% of CaO, 3% of NaOH and 1.5% of CaO + 1.5% of NaOH, and subparcels for the two periods of treatment (24 and 48 hours). The treatment did not have any effect and nor neither for period of DM (35,8%) nor of CD (2,7%). The contents of NDF, ADF and cellulose were lesser in the treatments with the addition of CaO, NaOH and CaO+NaOH, mainly to the treatment period of 48 hours. The lignin content was not affected by the applied treatments 10.2%. The application of 3% of CaO, 3% of NaOH and 1.5% of NaOH + 1.5% of CaO increases the digestibility of elephant grass, and the most significant effect occurs when using NaOH.<br>Objetivou-se estimar os teores de matéria seca (MS), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), celulose, hemicelulose, lignina, cinza e digestibilidade do capim-elefante em estádio de maturação avançado, submetido à aplicação com óxido de cálcio (CaO), hidróxido de sódio (NaOH) e CaO+NaOH, em dois períodos de tratamento. O experimento foi conduzido segundo um esquema de parcelas subdivididas em quatro tratamentos e quatro repetições, em que as parcelas foram constituídas da seguinte forma: sem aditivo, 3% de CaO, 3% de NaOH, e 1,5% de CaO + 1,5% de NaOH, com base na matéria natural. Já as subparcelas foram determinadas pelos períodos de tratamento (24 e 48 horas). Não houve diferença para teor de MS (35,8%) e de PB (2,7%). Já os teores de FDN, FDA e celulose foram menores nos tratamentos com adição de CaO, NaOH e CaO+NaOH no período de tratamento de 48 horas. O teor de lignina não foi afetado, e o valor médio observado de 10,2%. A adição de 3% de CaO, 3% de NaOH e 1,5% CaO + 1,5% NaOH aumenta a digestibilidade in situ do capim-elefante, com efeito mais marcante quando se utiliza o NaOH

Dynamics, production and quality of “Brachiaria brizantha” subjected to water diet and nitrogen fertilization Dinâmica, produção e qualidade da "Brachiaria brizantha" submetida a regime hídrico e adubação nitrogenada1

The experiment was conducted in vegetation house of the area of Forragicultura and Pasture of the State University of Southwest Bahia, from January to June 2009. The treatments were 4 diet water (20, 40, 60 and 80% of field capacity) and 2 nitrogen levels (0 and 150kg N/ha) with four replications. We used a completely randomized design in a factorial 4 x 2. The studied morphogenical characteristics were: leaf appearance rate, leaf elongation rate, phyllochron, leaf life span and rate of stem elongation; and the structural were: final leaf length, total number of leaves, number of leaves in senescence, number of dead leaves, maximum height of plant, number of tillers per plant and number of tillers per pot than the dry matter production of shoots and roots as well as the chemical components of air stop. The results had demonstrated that the interaction between diet water x doses of nitrogen was significant for the productions of natural matter, dry matter of the aerial part and roots. The results had evidenced that the practical of the nitrogen fertilization and the irrigation contributes positively in the forage production and development of the Brachiaria brizantha cv. MG-5.<br>O experimento foi conduzido em casa de vegetação da Universidade Estadual do Sudoeste da Bahia, de janeiro a junho de 2009. Os tratamentos utilizados foram quatro regimes hídricos (20, 40, 60 e 80% da capacidade de campo) e duas doses de nitrogênio (0 e 150kg de N/ha) com quatro repetições. O delineamento utilizado foi o inteiramente casualizado, em esquema fatorial 4 x 2. As características morfogênicas avaliadas foram: taxa de aparecimento foliar, taxa de alongamento foliar, filocrono, duração de vida da folha e taxa de alongamento do colmo; e as estruturais: comprimento final da folha, número total de folhas, número de folhas em senescência, número de folhas mortas, altura máxima da planta, número de perfilhos por planta e número de perfilhos por vaso, além da produção de matéria seca da parte aérea e das raízes bem como a composição químico-bromatológica da parte aérea. A interação entre regime hídrico x doses de nitrogênio foi significativa para as produções de matéria verde, matéria seca da parte aérea e de raízes. Os resultados evidenciaram que a prática da adubação nitrogenada e da irrigação contribui positivamente no desenvolvimento e na produção forrageira em gramíneas da espécie Brachiaria brizantha cv. MG-5

Chlorophyll and carbohydrates in Arachis pintoi plants under influence of water regimes and nitrogen fertilization

In this experiment the chlorophyll and carbohydrate contents of Arachis pintoi were evaluated to verify if the presence of nitrogen in the soil could contribute to the effectiveness of the establishment of this legume. The design was completely randomized, in a 4 × 4 factorial arrangement, with four N rates (0, 40, 80 and 120 kg ha-1) and four irrigation levels (25, 50, 75 and 100% of field capacity), with four replications. The biochemical evaluations of chlorophylls a and b and total chlorophyll and total soluble sugars, sucrose and starch were performed. The highest contents of chlorophyll a and b and total chlorophyll in leaves were found at the dose of 120 kg ha-1. The water regime of 25% of field capacity was responsible for the lowest content of reducing sugars and total soluble sugars in leaves, stolons and roots. In the roots, the sucrose contents were higher in these conditions, which can be associated with a slight tolerance of the plant to water stress. The water deficiency was responsible for the decrease of reducing sugars and total N in the whole plant and positively influenced the levels of chlorophyll and sugars in the stolon, promoting growth, especially of shoots, at the beginning of establishment