Metabolismo comparado de jardins de fungo de formigas Attini

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

Extração e exportação de nutrientes pelo feijoeiro adubado com nitrogênio, em diferentes tempos de implantação do sistema plantio direto

Common bean grown in no-tillage (NT) systems has increased markedly in Brazil. Thus, to optimize the fertilizer recommendations, it is important to know the nutritional requirements of this crop when grown under new and established NT systems, which can change the nutrient availability and crop response to nitrogen (N) fertilization. The objective was to evaluate the extraction and exportation of nutrients by common bean as function of N fertilization on soil under new and established NT systems. The experiment was carried out in two agricultural years, on a Red Nitosol (Alfisol) in Botucatu, São Paulo State, Brazil. A randomized complete block design was used in a split-plot scheme with four replications. The plots consisted of areas under NT systems after different periods of adoption and the subplots of four forms of N application to common bean (T0: control, without nitrogen; T1: 60 kg ha-1 before sowing; T2: 60 kg ha-1 sidedressed at V4 stage; and T3: 60 kg ha-1 before sowing + 60 kg ha-1 sidedressed). The following properties were evaluated: shoot dry matter, nutrient concentration and accumulation in the shoot, grain yield, and nutrient concentration and exportation in the grains. The NT age did not affect common bean yield, nutrition and response to N management. Nitrogen application, especially before sowing, led to higher dry matter and nutrient accumulation by common bean. The nutrient concentration in grains was little influenced by N fertilization. Grain yield and nutrient exportation were highest after double N application (before sowing and sidedressed) or only sidedressed at V4.

Simple agrometeorological models for estimating Guineagrass yield in Southeast Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Produção de forragem e composição estrutural de pastos de Brachiaria brizantha cv. Xaraés manejados em diferentes alturas de pastejo

The objective of this study was to analyze the production of dry mass, forage accumulation rate and the structural composition of Brachiaria brizantha cv. Xaraes pastures, managed under different grazing heights in continuous stocking. The experimental area was 12 hectares, divided in paddocks of one hectare each. The treatments were 15, 30, 45 and 60 cm of defoliation heights. Nellore steers were used to reach the desired heights. Every 28 days four cut samples and eight visual samples were collected for comparative performance in the experimental plots. Two grazing exclusion cages were used per treatment to estimate accumulation rates kg.ha(-1) DM. The cut material was taken to the laboratory for separation of the botanical components (green leaf, stem and senescent material), weighing and determination of dry matter. The experimental design was the completely randomized with three replicates. There were treatments effects at all seasons for the production of total mass, except in the spring. In summer and spring seasons it was observed the highest values for leaf blades (1.100 kg DM.ha(-1)). In the winter, the highest values of senescent material was observed, as expected. The average accumulation showed no significant difference among the treatments, except for stem and total mass in the summer and stem in the fall. The tillers were heavier and higher values for number of green leaves per tiller occurred in the fall, but for senescent leaves per tiller ocurred in the winter. Swards grazed at heights between 45 and 60 cm of defoliation, had good production of forage mass and leaf constituent.

Marcha de acúmulo de matéria-seca e de nutrientes pelo milho superdoce

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Leaf gas exchange and yield of three upland rice cultivars

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

Interferência das plantas daninhas na nutrição e produtividade da cultura da berinjela cultivar 'Nápoli' com e sem tutoramento e desbrota

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Acúmulo de nutrientes e tempo de decomposição da palhada de espécies forrageiras em função de épocas de semeadura

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

Acúmulo de matéria seca e macronutrientes por cultivares de sorgo sacarino

Nutrient accumulation curves help us understand the nutritional demands of a crop. The aim of this study was to evaluate the growth and accumulation of macronutrients by the sweet sorghum cultivars CVSW80007, CVSW80147, CVSW82028, CVSW82158. The experiment was conducted in a renewal sugarcane ratoon area at Uchoa county, SP, being deployed in January 2012. The plants were collected in 15 days intervals from the 10th after emergence (DAE). The greatest content of dry matter, N, P, Mg and S, was due to by the CVSW82028 cultivar, while the CVSW82158 extract the greatest amount of K and the CVSW80147 of Ca. The stalks represented the highs percentage of dry matter and nutrient content, except nitrogen and phosphorus, in which grains corresponded to the higher percentage of total absorption. The CVSW80007, CVSW82028 and CVSW82158 cultivars showed the following decreasing nutrient extraction N>K>Ca>Mg>P>S and the CVSW80147, K>N>Ca>Mg>P>S. Considering only the stalks harvest, the decreasing nutrient exportation is the same for all cultivars: K>N>Ca>Mg>S>P. Whereas the decreasing nutrient exportation sequence considering stalks and grain harvest is the following for the CVSW80007, CVSW80147 and CVSW82158 cultivars: K>N>Ca>Mg>P>S and K>N>Ca>Mg>P>S for the CVSW82028.

Relação amônio e nitrato, mitigação da toxicidade amoniacal com silício e curva de acúmulo de nutrientes em mudas de maracujazeiro

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Adubação potássica na produção e qualidade pós-colheita do rabanete

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Soil fertility, nutrition and early growth of physic nut as affected by nitrogen fertilization

The initial growth and mineral nutrition of the physic nut (Jatropha curcas L.) as a function of nitrogen (N) fertilization was investigated. The transplanting of seedlings was carried out in plastic pots filled with 50 dm3 of a Rhodic Hapludox, under a plastic greenhouse. In addition to a control treatment, the dosages of 0, 40, 80, 120, and 160 mg dm−3 N were tested. The results demonstrated that N fertilization for the cultivation of physic nut could be added as top dressing from 60 days after planting with a dosage of 65 mg dm−3. A SPAD index of 46 can be used as a nutritional reference to its initial development. Furthermore, the results suggested that the order of nutrient accumulation by the physic nut plants is as follows: potassium (K) > N > magnesium (Mg) > calcium (Ca) > phosphorus (P) > sulfur (S) > iron (Fe) > manganese (Mn) > boron (B) > zinc (Zn) > copper (Cu).