Épocas de semeadura de cultivares de feijoeiro no período de inverno sob diferentes palhadas no cerrado: produtividade e qualidade fisiológica de sementes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sugarcane trash management assessed by the interaction of yield with soil properties

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

Efeito da cobertura do solo com palhiço de cana-de-açúcar na emergência de monocotiledôneas infestantes em campo

Pós-graduação em Agronomia (Agricultura) - FCA

Evapotranspiração e eficiência do uso da água no primeiro ciclo produtivo da figueira 'Roxo de valinhos' submetida a cobertura morta

Evaluated the evapotranspiration (ETc) and the efficiency of water use (USA) by the fig tree 'Purple Valinhos' submitted to irrigation and mulching (bagacilho of sugar cane crushed) in the first production cycle, at conditions of Botucatu, St. Paul. We used the method of soil water balance and to obtain the reference evapotranspiration method was used Montheit FAO Penman 56. For the assessment of crop coefficients (kc) we adopted the following phenological distribution: phase 1 - between transplanting and 20% of the vegetative (DV), ii) phase 2 - 20 to 80% DV, and iii) phase 3 - fruiting. Observe the cumulative ETc 409.4 and 465.8 mm in 254 days after transplanting (DAT) and averages of 1.47 and 1.67 mm day(-1), with and without mulching (CC and SC). The crop coefficients (kc) mediums were 0.16, 0.43 and 0.49 for SC and 0.18, 0.44 and 0.50 for CC, in phases 1 and 3, respectively. The EUA values decrease with increasing the volume of water received and ranged between 1.65 and 3.32 kg of green figs per m(3) of water for irrigated SC and CC.

Rice-Straw Mulch Reduces the Green Peach Aphid, Myzus persicae (Hemiptera: Aphididae) Populations on Kale, Brassica oleracea var. acephala (Brassicaceae) Plants

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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

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

TANZANIA GRASS STRUCTURE GRAZED BY GOATS MANAGED WITH DIFFERENT RESIDUAL LEAF AREA INDEX UNDER INTERMITTENT STOCKING

The objective of this study was to evaluate the structure of Tanzania grassland grazed by goats managed with different residue leaf area index (RLAI) under intermittent stocking. The experiment was carried out from February to August, 2008. The treatments consisted of three different targets RLAI (0.8, 1.6 and 2.4) and 95% light interception (LI) criterion determined the rest period. Forage samples were collected at average height sampling points and weighed. Subsequently, a smaller sample was removed to separate the morphological components (leaf, stem and dead material) and to determine the structural and productive features. The canopy architecture was evaluated by the method of inclined point quadrat. The pre-grazing height in the paddocks were significantly different among treatments. RLAI influenced dry matter contents of green forage, leaf, stem and total, with the exception of dry matter of dead material, where the lowest values were observed for 0.8 RLAI. Thus, RLAI modifies canopy structure and is sensitive to canopy height changes throughout the year. Pasture regrowth is not compromised by residual leaf area indexes between 0.8 and 2.4, when climatic factors are not limiting.

Marandu grass management and supplementation on performance and methane mitigation of Nellore bulls

Pós-graduação em Zootecnia - FCAV

Aplicação em subdose do haloxyfop-methyl na aveia-preta

One of the major constraints to sustainable of the tillage is the rapid decomposition of dry the matter. One of the mechanisms known to facilitate this process is the interference in pathways of polymers of lignin from tests of application of low doses of herbicide based on the relation that higher the content of the lignin greater the resistance to degradation. With this purpose, the herbicide Verdict * R (haloxyfop-methyl) was used to verify the effect of low doses at the height of the plants, productivity of dry matter and in the metabolism of the lignin in plants of black oat. Preliminary tests in the greenhouse were realized for adjustments ​​to the best low doses to be applied in the definitive experiment in the production area. The results obtained were 24% of increase in productivity in the experiments conducted in greenhouse, from the application of 3.125g of the active ingredient of the haloxyfop-methyl per hectare, in this subdose no changes was observed in growth and content of lignin in plants of black oat. In the field, the concentration of 2.5g i. a. ha-1 of haloxyfop-methyl decreased in 9% the lignification rate without interfering with the height and productivity of the plants, this being favorable to the degradation rate of stubble tillage on outcome

Organic material decomposition and nutrient dynamics in a mulch system enriched with leguminous trees in the Amazon

As novas técnicas propostas para a agricultura na Amazônia incluem sistema de rotação de capoeira enriquecido com árvores leguminosas e transformando a queima da biomassa em cobertura morta sobre o solo. A decomposição e a liberação de nutrientes da cobertura morta foram estudadas usando sacos de liteira com malha fina que continham cinco tratamentos com diferentes espécies de leguminosas em comparação a um tratamento-controle com vegetação natural. As amostras para cada tratamento foram analisadas para conteúdos de C total, N, P, K, Ca, Mg, lignina, celulose e polifenóis solúveis em diferentes tempos de amostragem durante um ano. A razão constante de decomposição variou com a espécie e com o tempo. A perda de massa nos sacos de decomposição foi de 30,1 % para Acacia angustissima, de 32,7 % para Sclerolobium paniculatum, de 33,9 % para Inga edulis e para a vegetação secundária, de 45,2 % para Acacia mangium e de 63,6 % para Clitoria racemosa. Foi observada imobilização de N e P em todos os tratamentos, sendo a mineralização do N negativamente correlacionada com o fenol, razão C/N, razão (lignina + fenol)/N, razão fenol/P e o conteúdo de N nos sacos de liteira. Depois de 362 dias de incubação no campo, 3,3 % de K, 32,2 % de Ca e 22,4 % de Mg permaneceram no material em decomposição. Os resultados evidenciaram que a baixa qualidade mineral e a alta quantidade de carbono orgânico e aplicado como cobertura morta podem limitar a quantidade de energia disponível para os microrganismos resultando em uma competição por nutrientes com as plantas agrícolas.

RB25-207 The Spindle-Tuber Disease: One Cause of "Run-Out" Seed Potatoes

The spindle-tuber disease is one of the most prevalent potato diseases occurring in all parts of Nebraska. It has been found in all varieties tested. It does much damage to the potato crop, in that it reduces the yield and injures the market quality of the potatoes. This 1925 publication discusses the spindler-tuber disease also known as "running-out" or degeneracy of seed potatoes; the distribution of the disease; effect upon yield and quality; symptoms of the different potato varieties; transmission of the disease and experiments; rate of increase of the disease; dry land versus irrigation in western Nebraska; straw mulching versus cultivation in eastern Nebraska; planting times; harvesting; and control.

EROSION LOSSES FROM RUNOFF: INTERACTION OF SOIL COVER AND EROSION CONTROL PRACTICE

The flow of sediment from cropped land is the main pollutant of water sources in rural areas. Due to this fact, it is necessary to develop and implement technologies that will reduce water and sediment discharges. Accordingly, an experiment was conducted in the Department of Biosystems Engineering - ESALQ / USP, Piracicaba - SP with the objective to evaluate the effect of different soil cover (bean, grass and bare ground) and erosion control practices (wide base terraces and infiltration furrows in slopes (no practices to control erosion)) while measuring water losses in runoff. The statistical design adopted was randomized blocks in a 3x3 factorial scheme resulting in 9 treatments with 3 replicates (blocks). The period of rainfall data collection was December 6, 2007 to April 11, 2008. A 21.1 cm diameter rain gauge was installed in the experimental area. Terraces were the most efficient practices for reducing erosion losses in the treatments with infiltration furrows being better than the control treatment. Bean was more effective than grass in reducing erosion. Bare ground was the least efficient.

Perdas de água e solo sob diferentes padrões de chuva simulada e condições de cobertura do solo

Este trabalho foi realizado com o objetivo de determinar as perdas de solo e água em um Argissolo Vermelho-Amarelo, submetido a quatro diferentes padrões de precipitação de chuva simulada e duas condições de cobertura: área com solo descoberto e com palhada após plantio de milho. O experimento foi conduzido no Campo Experimental da Embrapa-Agrobiologia, localizado no município de Seropédica-RJ, e consistiu na aplicação de chuvas simuladas com diferentes padrões, caracterizados como avançado (AV), intermediário (IN), atrasado (AT) e constante (CT), em uma área amostral de 0,80 m de largura por 1,0 m de comprimento. Utilizando um simulador de chuvas portátil, foram aplicadas chuvas com 30 mm de lâmina total durante 60 minutos. Nos padrões com intensidade variada, o pico de precipitação foi de 110 mm h-1. Os resultados obtidos possibilitaram concluir que a cobertura do solo com resíduos de milho reduziu substancialmente as taxas e perdas de água e solo, principalmente para o padrão de chuva constante, indicando que a palhada deixada sobre o solo após a colheita auxilia de maneira efetiva no controle da erosão.

Escoamento superficial na interação: cobertura vegetal e práticas de controle de erosão

O escoamento da água oriunda das terras agricultadas é o principal fator poluente dos mananciais hídricos nas áreas rurais. Devido a esse fato, faz-se necessário o desenvolvimento e a aplicação de tecnologias que venham a reduzir descargas de resíduos indesejáveis. Nesse sentido, conduziu-se um experimento na área experimental do Departamento de Engenharia Rural - ESALQ/USP, Piracicaba - SP, com o objetivo de avaliar o efeito de diferentes condições de solo, (feijão, gramínea e solo nu) e diferentes práticas de controle de erosão (sulco de infiltração, terraço de infiltração e sem práticas de controle de erosão), buscando-se estimar o escoamento superficial. O delineamento estatístico adotado foi o em blocos aleatorizados, em esquema fatorial 3x3, perfazendo 9 tratamentos com 3 repetições. O período de coleta de dados pluviométricos foi de 06 de dezembro de 2007 a 11 de abril de 2008; para isto, utilizou-se de um pluviômetro, com 21,1 cm de diâmetro, instalado na área experimental. Observando-se as perdas de água, em relação às estruturas, tem-se em ordem decrescente de eficiência: Terraço, Sulco e Rampa; e com relação às coberturas, tem-se em ordem decrescente de eficiência: Feijão, Capim e Solo Nu.

Fluxes of CO2 above a sugarcane plantation in Brazil

Fluxes of CO2 were measured above a sugarcane plantation using the eddy-covariance method covering two growth cycles, representing the second and third re-growth (ratoons) harvested with stubble burning. The total net ecosystem exchange (NEE) in the first cycle (second ratoon, 393 days long) was −1964 ± 44 g C m−2; the gross ecosystem productivity (GEP) was 3612 ± 46 g C m−2 and the ecosystem respiration (RE) was 1648 ± 14 g C m−2. The NEE and GEP totals in the second cycle (third ratoon, 374 days long) decreased 51% and 25%, respectively and RE increased 7%. Accounting for the carbon emitted during biomass burning and the removal of stalks at harvest, net ecosystem carbon balance (NECB) totals were 102 ± 130 g C m−2 and 403 ± 84 g C m−2 in each cycle respectively. Thus the sugarcane agrosystem was approximately carbon neutral in the second ratoon. Yield in stalks fresh weight (SFW) attained the regional average (8.3 kg SFW m−2). Although it was a carbon source to the atmosphere, observed productivity (6.2 kg SFW m−2) of the third ratoon was 19% lower than the regional average due to the lower water availability observed during the initial 120 days of re-growth. However, the overall water use efficiency (WUE) achieved in the first cycle (4.3 g C kg−1 H2O) decreased only 5% in the second cycle. © 2013 Elsevier B.V. All rights reserved