996 resultados para Mineral nutrition
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The objective was to evaluate the effects of omitting macronutrients in the nutrients solution on growth characteristics and nutritional status of eggplants. The treatments were complete nutrients solution and solutions with nutrient omission: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). The experiment was carried out under greenhouse conditions with three replicates in a completely random design. Plant height, number of leaves per plant, leaf area, relative chlorophyll index, photosynthesis rate, stomatal conductance, dry matter, concentration levels of macronutrients in plant aerial part and root system, and nutritional disorders were evaluated. Omitting elements interfered in the concentration of elements in the various plant tissues and this had as consequences limited vegetative growth, reduced dry matter and led to the development of the typical deficiency symptoms of each element. Although potassium was the most demanded of all elements, nitrogen and calcium were the most growth limiting ones.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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This study evaluated the effects of organic and inorganic sources of minerals in diets for mid-lactation dairy cows on milk yield and composition, intake and total apparent digestibility of dry matter and nutrients, blood parameters, microbial protein synthesis, and energy and protein balances. Twenty Holstein cows averaging 146.83 +/- 67.34 days in milk and weighing 625.30 +/- 80.37 kg were used. The experimental design was a crossover. Diets were composed of corn silage (50%), ground grain corn, and soybean meal, differing with regard to the sources of trace minerals, plus an organic and inorganic mix. The organic mineral source increased milk fat and fat-corrected milk yield without changing milk yield, intake, or total apparent digestibility. Blood parameters, microbial protein synthesis, and energy and protein balances were not affected by the sources of minerals. Organic sources of minerals improve milk fat yield without affecting other parameters.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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The soil acidity in no tillage system could be resolved by lime superficial application, improvement to crop mineral nutrition and yield. The experiment carried out on a Rhodic Kandiudalf in Botucatu, São Paulo State, Brazil, in dry conditions, aiming to evaluate the agronomic development and leaf diagnosis of black oat plants, under superficial liming in no tillage system. A randomized complete block design was used, with four replications, the treatments were superficial application of different dolomítico lime rates (R0 = zero – without lime; R1 = 1,8 t ha-1 – lime to increase the base saturation at 50%; R2 = 3,6 t ha-1 – lime to increase the base saturation at 70% and R3 = 5,4 t ha-1 – lime to increase the base saturation at 90%), in October 2002. The black oat Common cultivar was seed in April 2004, in to second year, after the crop rotation of millet (spring) – common bean (summer) – black oat (autumn-winter). The results showed that: the black oat had yield increase by superficial liming, mainly to most dry matter and grain per panicule. Beyond, the superficial liming application did not prejudice leaf diagnosis of culture.
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Information on improved cultivars of fall panicum and cultural practices concerning its cultivation is scarce in Brazil. So, the objectives of this research work were to evaluate root length and the mineral nutrition of fall panicum plants as influenced by liming in an acidic soil. The experiment was conducted in vases containing 13 dm3 of soil under greenhouse conditions up to 44 days after seedling emergence. The experimental units were distributed inside the green house according to a completely random design in a 2 X 4 factorial scheme, that is, two fall panicum cultivars (‘AL Mogi’ and ‘AL Tibagi’) and four doses (0.0, 1.67, 2.91, and 4.15 t ha-1 ). The experimental units were replicated 4 times. ‘AL Tibagi’ plants root system showed more tolerance to soil conditions of low base saturation. That cultivar also absorbed more efficiently P, N, Ca, Mg, and K from the acidic soil. Liming brought about increments of P, N, Ca, Mg, and S absorption by the fall panicum cultivars.
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The aim of the work was to evaluate the productivity, leaf nutrient content and soil nutrient concentration in maize (Zea mays L.) grown in sequence with black oats (Avena strigosa Schreb.) under Leucaena diversifolia alley cropping agroforestry system (AFS) and traditional management system/sole crop (without trees-TS), after two years of cultivation following a randomized block design. The experiment was carried out in the Brazilian Association of Biodynamic Agriculture, in Botucatu—S?o Paulo, Brazil. Treatments were: control (C), chemical fertilizer application (F), biomass of L. diversifolia alley cropping application (B), biomass of L. diversifolia alley cropping + chemical fertilizer application (B + F). In the second year of management it was observed that black oat yield was higher in treatments B + F and F with significant difference in relation to the others treatments in both systems, followed by treatment B. Between systems, only treatment B showed significant difference, with higher yield value corresponding to AFS, reflecting the efficiency of AFS to promote soil fertility. Maize production presented the second year of cultivation an increasing trend in all treatments in both production systems. This result may be due to the cumulative effect of mineralization and maize straw and oats, along the experiment. How productivity was higher in the AFS system, could also be occurring effect of biological nitrogen fixation, water retention and reduction of extreme microclimate through the rows of L. diversifolia. Comparing the AFS and TS, it was observed that the concentration of N in leaf tissue was higher in the AFS treatments, probably due to nitrogen fixation performed through the rows of L. diversifolia, that is a nitrogen fixing tree species. After two years, carbon stocked in soil show higher values in the treatments biomass + fertilizer and biomass application, in both systems, AFS and TS.
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O trabalho teve como objetivo avaliar o efeito da aplicação do Stimulate e Forth Seed associados a cinco doses de fósforo(P) no desenvolvimento do sistema radicular e parte aérea de plantas de feijão. O experimento foi desenvolvido em condições de casa de vegetação nas dependências do Departamento de Recursos Naturais – Ciência do Solo, da Faculdade de Ciências Agronômicas (FCA), UNESP, Campus de Botucatu, SP. O solo usado foi um Latossolo Vermelho Escuro de textura média. As unidades experimentais foram vasos contendo 8 dm3 de solo mantendo-se a umidade correspondente a 60% do Volume Total de Poros (VTP) ocupados por água. Utilizou-se a cultivar de feijão IAC-Carioca, em um delineamento experimental inteiramente casualizado, sendo os tratamentos constituídos de dois produtos (Stimulate e Forth Seed) nas respectivas doses 5 e 3 mL Kg-1 de sementes e uma testemunha sem biofertilizante, e 5 doses de P (0, 16, 32, 64 e 128 mg dm-3), com três repetições. Foi avaliada, também, a qualidade fisiológica das sementes usadas no experimento por meio de: a) primeira contagem do teste padrão de germinação; b) emergência; c) vigor, mediante a contagem de emergência; d) velocidade de emergência e determinação do crescimento das plântulas. O uso de Stimulate e Forth Seed agregados a doses de P causou redução no peso seco final das plantas.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Sewage sludge has been used to fertilize coffee, increasing the risk of metal contamination in this crop. The aim of this work was to study the effects of Cd, Zn and Ni in adult coffee plants growing under field conditions. Seven-year-old coffee plants growing in the field received one of three;loses of Cd, Zn or Ni: 15,45 and 90 g Cd plant(-1); 35, 105 and 210 g Ni plant(-1); and 100, 300 and 600 g Zn plant(-1), with all three metals in the form of sulphate salts. After three months, we noticed good penetration of the three metals into the soil, especially in the first 50 cm, which is the region where most coffee plant roots are concentrated. Leaf concentrations of K, Ca, Mg, S, B, Cu, Fe and Mn were nor affected. N levels did not change with the application of Ni or Zn but were reduced with either 45 or 90 g Cd plant(-1). Foliar P concentrations decreased with the addition of 45 and 90 g Cd plant(-1) and 600 g Zn plant(-1). Zn levels in leaves were not affected by the application of Cd or Ni. The highest concentrations. of Zn were found in branches (30-230 mg kg(-1)), leaves (7-35 mg kg(-1)) and beam (4-6.5 mg kg(-1)); Ni was found in leaves (4-45 mg kg(-1)), branches (3-18 mg kg(-1)) and beans (1-5 mg kg(-1)); and Cd was found in branches (0-6.2 mg kg(-1)) and beans (0-1.5 mg kg(-1)) but was absent in leaves. The mean yield of two harvests was not affected by Ni, but it decreased at the highest dose of Zn (600 g plant(-1)) and the two higher doses of Cd (45 and 90 g plant(-1)). Plants died when treated with the highest dose of Cd and showed symptoms of toxicity with the highest dose of Zn. Nevertheless, based on the amounts of metal used and the results obtained, we conclude that coffee plants are highly tolerant to the three metals tested. Moreover, even at high doses, there was very little transport to the beans, which is the part consumed by humans. (C) 2011 Elsevier B.V. All rights reserved.