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The objective of this study was to evaluate the ability of savanna thinning and enrichment with grasses to maintain local biodiversity and intensify biomass production in an area of Caatinga. The study was carried out in a Caatinga area thinned into savanna and an unmanipulated area during the rainy and rainy-dry transition seasons of 2016. The herbaceous biomass production, diversity, and equability of the thinned and unmanipulated areas were evaluated by calculating values of the Shannon-Weaver (H') and Pielou (J') indices. The establishment of massai and buffel grasses in the savanna-thinned area was also evaluated. The area thinned into savanna produced more native herbaceous forage biomass in both the rainy (1,940.55 kg ha-1) and rainy-dry transition seasons (1,918.55 kg ha-1) than that in the unmanipulated area in the same periods (78.42 and 37.40 kg ha-1, respectively), without compromising biodiversity, as the Shannon-Weaver and Pielou indices for the savanna-thinned area (H' = 1.48 and J' = 0.62, respectively) and for the unmanipulated area (H' = 1.29 and J' = 0.72) were comparable. The frequency of species with a known forage value in the area thinned into savanna was still able to increase by 141% in the rainy season and 1,700% in the rainy-dry transition season. Massai grass became better-established in the savanna-thinned area that buffel grass, where it produced up to 3 t of dry matter ha-1. The thinning and enrichment treatments promoted an increase in the biodiversity of the area, and moreover contributed to increases in forage biomass in the Caatinga. [O manejo da pastagem natural incrementa a biomassa herbácea nativa e exótica e a biodiversidade na Caatinga no Brasil]. Resumo: Objetivou-se avaliar o raleamento em savana e o enriquecimento com gramíneas em uma área de Caatinga mantendo a biodiversidade local e intensificando a produção de biomassa. Os estudos foram conduzidos numa Caatinga raleada em savana e numa área não manipulada no período chuvoso que foi dividido em duas épocas em 2016. Avaliaram-se a produção de biomassa herbácea, a diversidade e a equabilidade pelos índices de Shannon - Weaver (H') e de Pielou (J') das áreas raleada em savana e não manipulada. Foi ainda avaliado o estabelecimento dos capins massai e búffel na área raleada em savana. A área raleada em savana produziu mais biomassa de forragem herbácea nativa tanto na época das águas (1.940,55 kg ha-1) quanto na época de transição águas-seca (1.918,55 kg ha-1) do que a área não manipulada nas mesmas épocas (78,42 e 37,40 kg ha-1, respectivamente), sem comprometer à biodiversidade, conforme os índices de Shannon-Weaver (H' = 1,48) e Pielou (J' = 0,62) para a área raleada em savana e H' (1,29) e J' (0,72), para a área não manipulada. A área raleada em savana foi ainda capaz de aumentar em 141% na época das águas e 1.700% na época de transição águas-seca, a frequência de espécies de conhecido valor forrageiro. O capim-massai apresentou melhor estabelecimento do que o capim-búffel, na área raleada em savana produzindo até 3 t de MS ha-1. O raleamento e o enriquecimento promovem um aumento da biodiversidade da área, além de contribuir para o incremento de biomassa de forragem. Made available in DSpace on 2019-04-26T00:47:38Z (GMT). No. of bitstreams: 1 cnpc2019Management.pdf: 2200302 bytes, checksum: 9acb401145267b6e0927099dc715dd86 (MD5) Previous issue date: 2019

The objective was to evaluate the chemical composition and in situ degradation of Maasai, Mombasa and Tanzania grasses belonging to the genus Panicum, at 22, 34 and 46 days after regrowth. The contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF) were determined. For the evaluation of ruminal degradation, 4 g sample were placed in nylon bags and incubated in the rumen of a fistulated animal, for 6, 24 and 72 h. The experiment had a completely randomized design for chemical composition analysis and a split-split plot completely randomized design for in situ degradation, with means compared by Tukey test at 5%. There was an increase in the contents of DM (+ 1.69%) and NDF (+ 5.06%) (P

The objective of this study was to evaluate the thinning into strips and the enrichment with exotic grasses in a Caatinga area in order to maintain and increase the biodiversity of native vegetable species and forage production. Two studies were carried out?one in an area of Caatinga thinned into strips and one in an unmanipulated Caatinga area?during the rainy and rainy-dry season transition periods in 2016. The production of herbaceous biomass was evaluated, and the diversity and equability of the two areas were assessed through Shannon-Weaver (H') and Pielou (J') indexes. The establishment of massai and buffel grasses at the center and edges of the area thinned into strips was also evaluated. During the rainy season, the production of herbaceous biomass in the area thinned into strips and the unmanipulated area was 1,228 kg ha-1 and 833.33 kg ha-1, while during the rainy-dry transition period, it was 1,973 kg ha-1 and 836.00 kg ha-1, respectively. The indexes remained similar: H' (1.86) and J' (0.74) for the area thinned into strips, and H' (1.77) and J' (0.85) for the unmanipulated area. The massai grass presented better establishment and development than that by the buffel grass in the center and edges of the area thinned into strips. Thus, thinning into strips increases the biodiversity of an area, and this combined with enrichment through grasses increases the biomass of herbaceous forage. Resumo: O objetivo deste estudo foi avaliar o raleamento em faixas e o enriquecimento com gramineas exoticas em uma area de Caatinga, de modo que fosse possivel manter e ou aumentar a biodiversidade de especies vegetais nativas, e intensificar a producao de biomassa de forragem. Dois estudos foram conduzidos em uma area de Caatinga raleada em faixas e em outra area de Caatinga nao manipulada no periodo chuvoso e transicao aguas-seca no ano de 2016. Avaliou-se a producao de biomassa herbacea e, a diversidade e equabilidade pelos indices de Shannon-Weaver (H') e Pielou (J') das areas raleada em faixas e nao manipulada. Foi ainda avaliado o estabelecimento dos capins massai e buffel ao centro e na lateral da area raleada em faixa. Na epoca das aguas a producao de biomassa herbacea na area raleada em faixas e nao manipulada foi de 1.228 kg ha-1 e 833, 33 kg ha-1, enquanto o periodo de transicao aguas-seca 1.973 kg ha-1 contra 836, 00 kg ha-1, respectivamente. Os indices permaneceram proximos H' (1, 86) e J?(0, 74), para a area raleada e H' (1, 77) e J' (0, 85) para a nao manipulada. O capim-massai apresentou melhor estabelecimento e desenvolvimento que o capim-buffel no centro e na lateral da area raleada em faixas. O raleamento em faixas aumenta a biodiversidade da area contribuindo juntamente com o enriquecimento no incremento de biomassa de forragem herbacea.

The objective of this study was to evaluate the thinning into strips and the enrichment with exotic grasses in a Caatinga area in order to maintain and increase the biodiversity of native vegetable species and forage production. Two studies were carried out?one in an area of Caatinga thinned into strips and one in an unmanipulated Caatinga area?during the rainy and rainy-dry season transition periods in 2016. The production of herbaceous biomass was evaluated, and the diversity and equability of the two areas were assessed through Shannon-Weaver (H') and Pielou (J') indexes. The establishment of massai and buffel grasses at the center and edges of the area thinned into strips was also evaluated. During the rainy season, the production of herbaceous biomass in the area thinned into strips and the unmanipulated area was 1,228 kg ha-1 and 833.33 kg ha-1, while during the rainy-dry transition period, it was 1,973 kg ha-1 and 836.00 kg ha-1, respectively. The indexes remained similar: H' (1.86) and J' (0.74) for the area thinned into strips, and H' (1.77) and J' (0.85) for the unmanipulated area. The massai grass presented better establishment and development than that by the buffel grass in the center and edges of the area thinned into strips. Thus, thinning into strips increases the biodiversity of an area, and this combined with enrichment through grasses increases the biomass of herbaceous forage. Resumo: O objetivo deste estudo foi avaliar o raleamento em faixas e o enriquecimento com gramíneas exóticas em uma área de Caatinga, de modo que fosse possível manter e ou aumentar a biodiversidade de espécies vegetais nativas, e intensificar a produção de biomassa de forragem. Dois estudos foram conduzidos em uma área de Caatinga raleada em faixas e em outra área de Caatinga não manipulada no período chuvoso e transição águas-seca no ano de 2016. Avaliou-se a produção de biomassa herbácea e, a diversidade e equabilidade pelos índices de Shannon-Weaver (H') e Pielou (J') das áreas raleada em faixas e não manipulada. Foi ainda avaliado o estabelecimento dos capins massai e búffel ao centro e na lateral da área raleada em faixa. Na época das águas a produção de biomassa herbácea na área raleada em faixas e não manipulada foi de 1.228 kg ha-1 e 833, 33 kg ha-1, enquanto o período de transição águas-seca 1.973 kg ha-1 contra 836, 00 kg ha-1, respectivamente. Os índices permaneceram próximos H' (1, 86) e J?(0, 74), para a área raleada e H' (1, 77) e J' (0, 85) para a não manipulada. O capim-massai apresentou melhor estabelecimento e desenvolvimento que o capim-búffel no centro e na lateral da área raleada em faixas. O raleamento em faixas aumenta a biodiversidade da área contribuindo juntamente com o enriquecimento no incremento de biomassa de forragem herbácea. Made available in DSpace on 2019-09-19T00:34:52Z (GMT). No. of bitstreams: 1 CNPC2019Forage.pdf: 887858 bytes, checksum: da078c7976c2c1e5c7477e5c068cec88 (MD5) Previous issue date: 2019

To evaluate the tillering dynamics of massai grass under rotational sheep stocking and fertilized with nitrogen (control - 0; 400; 800 and 1200 kg ha-1 year-1), this study was carried out, in a completely randomized design with repeated measures over time. The mob-grazing technique was applied to perform the grazing by employing groups of animals for rapid defoliation. The tiller appearance, survival and mortality rates, tiller biomass, and green/dead tillers ratio, have presented increase responses to nitrogen levels, with the three rates and the tiller biomass varying between evaluation periods. There was a quadratic response for the tiller flowering rate, population density of vegetative and reproductive tillers, reaching maximum values (0.051 tiller 100 tiller-1 day-1; 4,818 and 35 tillers m-2, respectively) under the nitrogen levels of 613.5; 993.5 and 623.9 kg ha-1 year-1, respectively. For the tiller flowering rate and population density of reproductive tillers, it was verified a fluctuation between periods. The nitrogen fertilization promotes positive changes in tillering dynamics of massai grass, allowing the use of up to 800 kg ha-1 year-1 for maintaining the pasture stability. The tillering demography of the forage had varied little between assessment periods.

O objetivo deste trabalho foi avaliar as características anatômicas e morfofisiológicas de lâminas foliares de genótipos de Panicum maximum e determinar quais as mais relevantes para a discriminação precoce do valor nutritivo de genótipos promissores. O experimento foi realizado entre janeiro de 2006 e novembro de 2007, em Dourados, MS. Foram avaliados 23 genótipos de P. maximum pré-selecionados do programa de melhoramento da Embrapa Gado de Corte. Utilizou-se o delineamento experimental de blocos ao acaso, com três repetições. Foram avaliadas 27 características anatômicas e morfofisiológicas de lâminas foliares em cada genótipo. Para cada característica estudada, os resultados foram agrupados pelo teste de Scott-Knott. A importância relativa das características avaliadas para a avaliação da divergência genética foi determinada pelo método de Singh. As características que melhor discriminaram os genótipos foram as proporções – na seção transversal das lâminas – das epidermes adaxial, abaxial, adaxial + abaxial, do mesofilo e do tecido vascular + esclerênquima. A área foliar específica, a área foliar e o comprimento de lâmina foram as características morfofisiológicas que mais contribuíram para a discriminação dos genótipos; porém, sua importância relativa foi muito menor que a das características anatômicas. A proporção ocupada pela bainha parenquimática dos feixes e a largura das lâminas apresentam instabilidade fenotípica. The objective of this work was to evaluate anatomical and morphophysiological traits of the leaf blade of Panicum maximum genotypes, and to determine which ones favor an early discrimination of promising genotypes for nutritive value. The experiment was carried out in Dourados, MS, Brazil, between January 2006 and November 2007. Twenty-three P. maximum genotypes, which were pre-selected from the Embrapa Gado de Corte breeding program, were evaluated. The experimental design was a randomized block, with three replicates. Twenty-seven anatomical and morphophysiological leaf blade traits were evaluated in each genotype. For each trait, the results were grouped by the Scott-Knott test. The relative contribution of the traits to genetic divergence was determined by the Singh method. The traits that best discriminated the genotypes were the proportion – in the leaf blade cross-sections – of upper, lower, and upper + lower epidermis, and of mesofile and vascular bundles + sclerenchyma. Specific leaf area, leaf area, and leaf blade length were the morphophysiological traits that showed higher contribution to genotype discrimination; however, their relative importance was much lower than that of the anatomical traits. The proportion of parenchymatic bundle sheath cells and blade width show phenotypic instability.