Root system and root and stem base organic reserves of pasture Tanzania grass fertilizer with nitrogen under grazing

The goal of this study was to evaluate the concentrations of non-structural carbohydrate (NSC) and of total nitrogen (N), as well as, to evaluate the root system in Tanzania-grass pastures fertilized with doses of urea in fall, spring and summer. The experiment was conducted at the Experimental Farm of Iguatemi, Maringa, Parana, Brazil, from March 2007 to March 2008. The experimental design was complete random blocks with subplots and four repetitions. The plots showed doses of N (50, 100 e 150 kg ha(-1) of N) plus the control (no N fertilization), and the subplots the season of the year. Root samples were taken at depths of 0-10, 10-20 and 20-40 cm. Root biomass showed a trend for mass accumulation up to a dosage of 100 kg ha(-1) for all seasons evaluated. Also, about 80% of the root system of Tanzaniagrass plants was found on the 0-10 cm layer for all dosages of N. Nitrogen fertilizer above 100 kg ha(-1) may foster fast forage plant growth reducing its NSC root storage capacity although favoring NSC and total N storage at stem base. NSC and total N concentrations were highest in fall, demonstrating that its usage is greater in spring due to the weather conditions being favorable to plant growth. In the regrowth, the largest reserve of total N was at the 0-10 cm root layer and the largest NSC reserve is at stem base.

Germoplasma do gênero Paspalum com potencial para produção de forragem

This study was carried out in Fazenda Canchim in Sao Carlos-SP, physical base of Embrapa Southeast Livestock, aiming to select, based on the agronomic characteristics of productivity of dry matter and quality of the forage, the accesses of suitable gender Paspalum for possessing potentiality of use as foraging plants. Were evaluated for 3 years, with 22 forage grasses, being 19 of Paspalum and three more of control species: Brachiaria decumbens, Andropogon gayanus cv. Baet and Panicum maximum cv. Tanzania, submitted to two intensification levels: high (fertilizer after each cut and supplemental irrigation) and low (only fertilizer of annual replacement without irrigation). The experimental design was of split blocks subdivided in the space and time with two replications. The studied variables were: dry matter production, in vitro dry matter digestibility and crude protein content. The results show that the accesses responded to the intensification level minimizing the negative effect of the stational production. Based on the studied variables, the selected accesses were: BRA-011401 (Paspalum glaucescens); BRA-011681 (P. atratum); BRA009661 (P. atratum) and BRA-019186 (P. regnellii).

Cover crops affecting levels of ammonium and nitrate in the soil and upland rice development

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise comparativa da produção e composição físico-química do leite considerando a utilização de diferentes volumosos na alimentação de vacas Girolando

Pós-graduação em Medicina Veterinária - FMVZ

Corn production for silage intercropped with forage in the farming-cattle breeding integration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determinação da melhor dose de virginiamicina em suplementos para bovinos Nelore em pastejo

Pós-graduação em Zootecnia - FCAV

Características morfogenéticas, perdas de nitrogênio por volatilização, reservas orgânicas e sistema radicular do capim-Tanzânia fertilizado com doses de nitrogênio

O objetivo do trabalho foi estudar as características morfogenéticas e estruturais do capim-Tanzânia, a produção de forragem, as perdas de nitrogênio (N) por volatilização, reservas orgânicas e a avaliação do sistema radicular sob doses de nitrogênio sob pastejo. O experimento foi instalado na área Fazenda Experimental de Iguatemi da Universidade Estadual de Maringá, no período de março de 2007 a março de 2008. O delineamento experimental utilizado foi de blocos completos ao acaso, com parcelas subdivididas com quatro repetições. Nas parcelas, encontravam-se as doses de N (0, 150, 300 e 450 kg ha-1 de N) e, nas sub-parcelas, as estações do ano. As perdas de N por volatilização foram quantificadas depois da adubação N (1, 2, 3, 6, 9, 12 e 15 dias). As amostragens das raízes foram realizadas nas profundidades de 0-10, 10-20 e 20-40 cm. A aplicação do fertilizante N na pastagem foi parcelada em três aplicações. A produção de massa seca total e de lâmina foliar de forragem respondeu linearmente até 282 kg ha-1 de N na estação do verão. A adubação nitrogenada exerce efeito positivo nas taxas de alongamento e aparecimento foliar, e no número de folhas vivas em plantas de capim-Tanzânia nas estações da primavera e verão. Elevadas adubações nitrogenadas associada a intervalos menores de pastejo promovem uma maior porcentagem de lâmina foliar; no manejo de pastos de capim-Tanzânia sob lotação rotacionada com altura de 70 cm na entrada dos animais para o pastejo e saída com 30 cm de altura do resíduo. A interação entre o nível de adubação e o período depois da aplicação de uréia foi significativa para a variável volatilização acumulada de N-NH3. A aplicação da uréia acarreta perdas percentuais mais elevadas de N nos três primeiros dias após a aplicação. A perda média acumulada de N-NH3 no período para as três estações do ano... (Resumo completo, clicar acesso eletrônico abaixo)

Simple agrometeorological models for estimating Guineagrass yield in Southeast Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Valor nutricional de silagem de capim-mombaça com aditivos agroindustriais

It was aimed to evaluate the chemical composition of grass silage-mombasa associated with different additives in four times of opening the silo. The experiment was conducted in UFGD. After harvesting the forage, biomass in natura crushed, was taken to the lab, homogenized and enriched on the basis of natural mass, with the following additives: 5% wheat bran, 5% of waste (broken grain and soy ice cream cone) of soybean, 5% urea in natural matter and the witness (without additive). The silos were opened after (unprocessed material), 15, 30 and 45 days, for the analysis of chemical composition. The data obtained were analyzed through the statistical programme SISVAR and averages were compared to 5% of probability, by Skott-Knot. The grass silage-mombasa without additive presented major (P<0.05) dry matter content compared to other treatments at time 0 and 30 days of silage and did not differ (P>0.05) of grass silage- mombasa associated with 5 of urea in 15 days and 45 of silage. The grass silage-mombasa with 5% urea showed the highest crude protein content at time 0 and differed from other treatments. The silage of mombasa associated with 5% urea provided greater in vitro digestibility of dry matter to 15 days of silage.

Degradação de palhada e liberação de nitrogênio por plantas de cobertura sob plantio direto

Crops used to cover the ground may also release nitrogen into the soil during mineralization. However, it is necessary to identify species that combine fast nutrient release and longer permanence of the straw on the soil surface. The aim of this study was to investigate straw degradation and nitrogen release from cover crops under no-tillage cropping systems. The field trial was performed during two growing seasons in summer (2008/2009 and 2009/2010) in the Cerrado region of Brazil. The experimental design was a randomized block in factorial arrangement. Treatments were the combination of five plants (four cover crops species, 1 - Panicum maximum, 2- Brachiaria ruziziensis, 3. Brachiaria brizantha and 4. Pennisetum glaucum [millet], and fallow as a control) with six sampling times (first six weeks after application of glyphosate on the cover crops). Pennisetum glaucum and fallow showed faster straw degradation and nitrogen release. The cover crops Panicum maximum, Brachiaria brizantha and Brachiaria ruziziensis stood out in biomass production and in the amount of nitrogen in their shoots but had the lowest coefficients of degradation and persisted longer on the soil surface than Pennisetum glaucum and fallow.

MORPHOGENESIS AND PRODUCTION OF TANZANIA, MOMBACA AND MULATO GRASSES UNDER NITROGEN FERTILIZATION

A field trial was conducted designed in a completely randomized block in a 4 x 3 factorial arrangement to evaluate the application of nitrogen doses (N) (0, 40, 80 and 160 kg/ha) on the morphogenical characteristics and dry matter partition of three forage grasses (Panicum maximum cvs. Mombasa and Tanzania and Brachiaria sp. Hybrid Mulato). The leaf appearance (LAR, leaf/day) and stretching (LER; mm/day) rates, the number of green leaves per tiller (NLT) and the average weight of tillers (MTW; g) presented s positive linear response to the N dose while the phyllochron (Phil; day/leaves) showed a negative linear response. The highest LER, IAL and final leaf length (FLL; cm) occurred in the Mombaca and Tanzania grasses, while the highest LAR occurred in the Mulato grass. There was a negative quadratic effect of the N dose on the stem elongation rate (SER; mm/day) and LF. The Mombaca and Tanzania grasses presented the highest SER; however, in just two forages. The production of total dry matter (TDM; kg/ha), leaves (LDM; kg/ha) and stems (SDM; kg/ha) increased linearly and quadratically with the N dose, respectively, for the Mombaca and Tanzania grasses. There was a high positive correlation among DM, LDM and SDM and the Mombaca grass MTW. The dry matter production and morphogenic characteristics were influenced by the nitrogen fertilization as a result of the substantial increase in the flow of tissues stimulated by fertilization, proving the importance of N for forage biomass accumulation.

Desempenho, qualidade de carcaça e da carne de cordeiros alimentados com dietas contendo silagens de milho consorciadas ou não com capins tropicais

Pós-graduação em Ciência e Tecnologia Animal - FEIS

Eficácia de óleos minerais aplicados como adjuvantes auxiliando na selitividade de herbicidas na cultura de cana-de-açúcar

Pós-graduação em Agronomia - FEIS

Performance and parasite control of different genetic groups of lambs finished in irrigated pasture

The aim of this study was to compare the following four genetic groups of hair sheep: Santa Inês (SI), Morada Nova (MN), Brazilian Somali (BS), and the F1 1/2Dorper x 1/2Morada Nova crossbreed on traits related to growth and parasitic infection. Thirty-three male lambs of the same age and of simple birth, under the same pre-weaning management conditions were used in the experiment. After weaning the animals were housed in a completely randomized design in paddocks made of Panicum maximum cv. Tanzania. Along the course of the research, the performance of the four groups of sheep was observed to be negatively affected by gastrointestinal parasites, but there was a genotype effect to the average daily weight gain (ADWG), where the SI and F1 genotypes presented higher values. The effects of genotype, time and genotype x time interaction were significant in weight and corporal score (CS) measurements. The BS lambs had the highest CS values throughout the experiment despite not presenting greater weight gain when compared to the SI and F1 breeds. There were also significant effects of time and genotype x time interaction for packed cell volume (PCV) and FAMACHA© score (FAM) and only the time effect was significant in the total number of eggs per gram (EPG) and total plasma protein (TPP). The MN lambs showed higher PCV values and unlike the other groups, presented a FAMACHA© score below 3 and PCV above 23% even having a higher EPG tendency, especially in the initial phase, indicating a possible higher resilience to infection caused by gastrointestinal parasites.

Interferência de plantas daninhas no desenvolvimento inicial de mudas meristemáticas de cana-de-açúcar

Pós-graduação em Agronomia (Produção Vegetal) - FCAV