Nitrogênio, fósforo e potássio na produção de massa seca e no acúmulo de nutrientes em mudas de limeira ácida 'tahiti'

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Crescimento de mudas de Schizolobium amazonicum (Huber ex Ducke) em substrato fertilizado com nitrogênio, fósforo e potássio

The nutritional management of seedlings in the nursery is one of the most important practices that influence seedling quality. The aim of this work was to evaluate the effect of nitrogen, phosphorus and potassium on the development of Schizolobium amazonicum seedlings grown in 250 cm containers with a commercial substrate in the North of Mato Grosso State, Brazil. The experimental design was completely randomized design with five treatments and five replications, each replication being represented by 24 seedlings. The treatments were: control (only commercial substrate); nitrogen fertilization (150 g m-3 N using ammonium sulfate + 1.0 kg of ammonium sulfate dissolved in 100 L of water and applied in coverage); phosphorus fertilization (300 g P2O 5 m-3 using simple superphosphate); potassium fertilization (100 g m-3 K2O using potassium chloride + 0.3 kg of potassium chloride dissolved in 100 L of water and applied in coverage) and; complete (a mixture of the three nutrients, 150, 300 and 100 g m-3 N, P2O5 and K2O, respectively + 1.0 kg of ammonium sulfate + 0.3 kg of potassium chloride). The commercial substrate was composted milled pine bark plus vermiculite. Evaluations of the seedlings were performed at 90 days after sowing. The complete treatment (NPK) gave the highest values for biometric and best plant indices, which express the quality. When analyzing nutrients in isolation; potassium had the lowest effect. Based on these results it can be recommended to fertilize Schizolobium amazonicum seedlings in nurseries with 150, 300 and 100 g m-3 of N, P2O5 and K2O, respectively, plus 1.0 kg of sulfate ammonium and 0.3 kg of potassium chloride applied in coverage.

Desenvolvimento, produtividade e composição bromatológica da primeira soqueira da cana-de-açúcar em função de fontes de fósforo

The aim of this study was to evaluate the development, yield and chemical composition of the first ratoon sugar cane, depending on the residual effect of phosphorus sources. The study was conducted in the municipality of Alta Floresta - MT. The experimental design was randomized blocks in factorial scheme 4x2, with four replications. The phosphorus sources were used: bone meal, Arad phosphate and triple superphosphate, and a control without the application of the nutrient. The varieties of sugar cane were planted IAC86-2480 and SP79-1011. We evaluated the plant height, stalk diameter, mass of a plant, number of stems, dry matter yield, P content of the plant and the chemical composition of the forage. The residual effect of fertilization, using different sources of phosphorus, no significant alterations in the development, yield and chemical composition of the first ratoon sugar cane, with little reduction in NDF and ADF when using the bone meal. The variety IAC86-2480 showed better results, providing a higher content of crude protein and phosphorus in the plant and increased production of dry mass.

Efeito residual de fontes de fósforo nos atributos químicos do solo, nutrição e produtividade de biomassa da cana-de-açúcar

In tropical regions, the residual effect of phosphate fertilizer source is of crucial importance. This study aimed to evaluate the effects of application of P sources in chemical properties of soil, nutrition and productivity of sugarcane plant and during the first and second ratoon. The sources of P applied in furrows at planting were, triple superphosphate, Arad phosphate, bone meal (100 kg ha-1 P2O5 total) and a control without P, the varieties of sugarcane studied were IAC86-2480 and SP79-1011. A randomized block design in a 4 × 2 factorial was used, with four replications. The study was conducted in the municipality of Alta Floresta-MT, Brazil, in Typic Hapludox. After each cutting, in soil P content, pH and Ca were evaluated. In the plant, the production of green and dry matter of shoots, the concentration of P in the biomass harvested, the export of P and agronomic efficiency of the sources of P were determined. The bone meal had a higher agronomic efficiency resulted in greater accumulation and export of P by crop, higher content of available Ca and P and increase soil pH. The Arad reactive phosphate increased its agronomic efficiency between crop cycles.

Formas de fósforo no solo após o cultivo de braquiária e tremoço branco

Phosphorus is one of the major factor that limits agricultural productivity in most tropical soils. The objective of this study was to assess P transformations and availability in a soil cropped to brachiaria (Urochloa ruziziensis) and white lupin (Lupinus albus L.). The study was carried out in a greenhouse at Botucatu, State of São Paulo, Brazil. Brachiaria and white lupin were grown in pots with soil fertilized with 0, 20, 40, 60 and 80mg dm-3 P. The plants were grown for 60 days, when they were harvested and the soil was sampled. Dry matter yields of both species were increased with P rates. Soil bioactive P is increased with P fertilization, but is not affected by the plant species. White lupin is more effective in taking up the organic soil P, but Brachiaria was more effective in reducing the soil maximum P adsorption capacity.

Remoción de fósforo de diferentes aguas residuales en reactores aeróbios de lecho fluidizado trifásico con circulación interna

The wastewater discharge produces impacts on receiving water bodies. Nutrients as P produce implications on lentic systems because they accelerate the eutrophication processes. Several technologies for P removal from the wastewater have been used: physic chemical treatment systems with important effects by coagulant products addition; biological processes based on anaerobic and aerobic conditions with great implications on the required volume; natural systems as stabilization ponds and irrigation require bigger areas and post-treatment processes. The aerobic fluidized bed reactors with internal circulation (AFBRIC) are compact options with high concentrations of active biomass that have demonstrated their capacity for organic matter and N removal. For sewage from the wastewater pumping station of Ilha Solteira city and effluents of a recirculation aquaculture system (RAS) for semi-intensive tilapia farming, the reactive P and total P removal efficiency in three AFBRIC with 250 mm external tube diameter and different internal tube diameter (ITD), for two different support media at different concentrations was evaluated. The average reactive P removal efficiency for domestic wastewater to hydraulic retention time (HRT) of 3 hours and 125 mm ITD reactor varied from 25,6 to 38,4% and with 150 mm ITD reactor varied from 27,5 to 32,5%; the average total P removal for the RAS wastewater at a HRT of 0,19 hours and 100 mm ITD was of 32,7%.

Doses e modos de aplicação de fósforo na nutrição e produção do feijoeiro cultivar Pérola

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos do glyphosate sobre o crescimento e absorção de fósforo pela soja

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Disponibilidade de fósforo em função da aplicação de calcário e silicatos em solos oxídicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Gesso de minério associado a fontes de fósforo na cultura do milho em sistema plantio direto no Estado de Alagoas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ciclagem e disponibilidade de fósforo para a soja em rotação com braquiária como espécie de cobertura

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variabilidade vertical de formas de fósforo em função de fontes e doses de fosfatos em semeadura direta

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

Disponibilidade de fósforo para a soja cultivada sobre braquiária

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

Eficiência agronômica de fertilizantes organominerais sólidos e fluidos em relação à disponibilidade de fósforo

Pós-graduação em Agronomia (Agricultura) - FCA

Efeito de dietas e altura da coluna d’água na sobrevivência de larvas de Betta splendens e o aporte de nitrogênio e fósforo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)