Desenvolvimento, produção e nutrição de trigo adubado com nitrogênio e potássio

Abstract

The wheat (Triticum aestivum L.) is a cereal widely used in feeding of human (mostly) and animal for their nutritional properties. Due to their adaptation, is grown both subtropical as tropical regions. Grain yield and technological quality characteristics are strongly influenced by climatic and meteorological conditions each region during the crop. Along with appropriate management of nitrogen and potassium fertilization is need the correct and efficient use of water, which is essential for the transport of these nutrients. The objective was to evaluate the effects of combined rates of nitrogen and potassium in the development, production and nutrition of wheat plants. The experiment was carried out a greenhouse in pots of 8 dm3. The soil used was Oxisol, collected at a depth of 0 a 0,2 m. Conducted the liming the soil to 60% of base saturation and incubating for 30 days to 60% of field capacity. Was adopted randomized block design in factorial 5x5 with five doses of nitrogen (0, 100, 200, 300 e 400 mg dm-3) and five doses of potassium (0, 90, 180, 270, 360 mg dm-3), with four replications. Soil moisture was maintained by autoirrigante system (controlled tension in 3 kPa). At 50 days after emergence, was taken reading the SPAD index in the diagnostic leaves (+1 and +2), being these removed from the plant to posteriorly nutritional analyzes in the laboratory. At 95 days after emergence, were harvested and separated in the shoot was dried in an oven with air forced ventilation 65 °C until constant weight, this material were separated the cobs for counting the grains. In a Willey mill were crushed the grains for the determination of nitrogen and potassium. The root system was cleaned and dried in an oven with air forced ventilation 65 °C until constant weight. The vegetative growth of plants was affected by nitrogen and potassium singly, the maximum leaf production was obtained at a dose of nitrogen of 278,1 mg dm-3. The diameter linear response to potassium fertilization. It was no interaction between the factors for production dry mass of shoots and total wheat plants. The efficient use of water increased linearly with nitrogen and potassium. Nutritional characteristics were influenced by the nutrients singly, where the potassium increased the concentration nitrogen and crude protein in grain. The supply of nitrogen and potassium in the soil promoted development gains, production and nutrition of wheat plants.