Absorção de nitrogênio pelo algodoeiro herbáceo em dois sistemas de cultivo

The study of nutrient uptake is of fundamental importance to plant nutrition, as well as tell the time (growth stage) being absorbed by the culture, also signals to the levels of fertilizer to be used. Aiming to establish the uptake of nitrogen for cultivation of cotton (Gossypium hirsutum L. r. latifolium Hutch.) led to an experiment in a Alfissol under randomized block design with two treatments, sowing conventional tillage and after tillage on the straw of previous crop (millet), with five replicates. Samples were taken according to the phenology and plants development. The dry matter accumulation in cotton is linear and increasing until the period of large boll, being more intense with the appearance of flowers and boll, or 50 to 100 days after emergence. The nitrogen content is higher in newly emerged plants, having peaks at the beginning of the appearance of squares and flowers, and from the appearance of small boll, the nitrogen content in the plant decreases linearly. The extraction of nitrogen is bigger from the appearance of flowers (55-60 days after emergence).

Deposição de sílica e teor de nitrogênio e silício em arroz

The nitrogen fertilization is an important practice to reach high productivity, however, nitrogen high level can cause lodging and make the plants more sensitive to disease. Numerous studies has demonstrate that a lot of grasses accumulate silicon at its tissues, and the biggest part of this element is deposited on the leaf, that would work like a mechanical barrier to diseases come in. However, high levels of nitrogen can reduce the silica deposition at the plants. The objective of this study was to evaluate silicon and nitrogen content in shoot and silica deposition in upland rice leaf as a result of Si and N levels. The experimental design used was completely randomized in factorial schema 3 x 2 with five replications. The treatments consisted from levels of N (5, 75 and 150 mg dm-3 of soil) in urea form and two levels of SiO2 (0 e 400 mg dm-3) in calcium silicate form (Wollastonita). The increased of urea fertilization reduced the silicon content of rice plants and the silica deposition at the external cells wall the epidermal rice leafs.

Produção de matéria seca da braquiária de acordo com os atributos químicos de um Latossolo em Selvíria, Mato Grosso do Sul

Rustic forages as the signal-grass are predominant in areas of Cerrado in extensive livestock systems that favor soil degradation. However, with time, not even these forages can have a good development in those areas. The objective of this study was to analyze the variability of plant and soil attributes; to define the linear and spatial correlations between signal-grass yield and the chemical attributes of the studied soil, and to evaluate, among the chemical attributes of the soil, which one that best explain the variability in this forage yield. The experiment was conducted in an area that had been under pasture for more than 30 years, belonging to UNESP - Ilha Solteira Campus, located in Selvíria - MS. A geostatistical grid was installed in an oxisol, for soil and plant data collection, with 121 sampling stations, consisted of eleven transections with 160 m width in the direction of the Cartesian axes. The dry mass yield of signal-grass was low, presenting high variation. The attributes MSr, N, PB, MO1, MO2, pHa1, pHa2, pHk1 and pHk2 did not vary at random. They presented data variability from low to high and followed clearly defined spatial patterns, ranging between 17.7-162.9 m. There was significant linear correlation at 1% between MSr and N leaf, and between MSr and PB. The cross semivariograms MSr=f(N) and MSr=f(PB) confirmed that the dry matter can be estimated from data of nitrogen leaf and crude protein content of this forage.

Resposta do feijoeiro (Phaseolus vulgaris L.) à adubação nitrogenada de cobertura em dois sistemas de manejo de solo

Pós-graduação em Agronomia (Agricultura) - FCA

Estimação de variáveis físico-químicas de solo por espectroscopia no visível e no infravermelho próximo através de sistemas inteligentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos ecológicos de um minador foliar em Erythroxylum tortuosum Mart. (Erythroxylaceae): qualidade da planta, anatomia das minas e variação hierárquica de traços vegetais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da suplementação da dieta com ácido fólico na colestase obstrutiva: estudo experimental em ratos jovens

Pós-graduação em Pediatria - FMB

Influência do despendoamento e da desfolha na produção e qualidade de sementes de milho

Pós-graduação em Agronomia - FCAV

Fertilização com lodo de esgoto e vinhaça e influência nas frações de nitrogênio do caldo e qualidade da cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Plantas de cobertura, fontes de nitrogênio e fornecimento de molibdênio no cultivo de arroz de terras altas em sistema de plantio direto

Pós-graduação em Agronomia - FEIS

Lâminas de água, inoculação de sementes com Azospirillum brasilense e doses de nitrogênio em arroz terras altas

Pós-graduação em Agronomia - FEIS

Resposta do feijoeiro ao preparo do solo, manejo de água e parcelamento da adubação nitrogenada

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

Fontes e épocas de aplicação de nitrogênio em feijoeiro de inverno em sistema plantio direto

Pós-graduação em Agronomia - FEIS

Uma abordagem baseada em redes neurais artificiais para a estimação de densidade de solo

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Investigação do processo de fixação biológica de N2 atmosférico na fermentação de fécula de mandioca

Pós-graduação em Agronomia (Energia na Agricultura) - FCA