Eficiência de utilização de nitrogênio, fósforo e potássio por plantas de papuã submetidas a diferentes intensidades de pastejo e níveis de nitrogênio
Nitrogen fertilization is usually noticed as an efficient nutritional factor offered to the plant with the aim to improve its production, being necessary to understand the nitrogen behave (N) in the system. The experiment was carried out at the Agronomist institute of Paraná (IAPAR), experimental...
| Autor principal: | Sartor, Laércio Ricardo |
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| Formato: | Dissertação |
| Idioma: | Português |
| Publicado em: |
Universidade Tecnológica Federal do Paraná
2012
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| Assuntos: | |
| Acesso em linha: |
http://repositorio.utfpr.edu.br/jspui/handle/1/255 |
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| Resumo: |
Nitrogen fertilization is usually noticed as an efficient nutritional factor offered to the plant with the aim to improve its production, being necessary to understand the
nitrogen behave (N) in the system. The experiment was carried out at the Agronomist
institute of Paraná (IAPAR), experimental unit of Pato Branco with the aim to evaluate the dynamic of N in the soil-plant system of a Brachiaria plantaginea. The experiment was laid out as random block design with two replications. The treatments were arranged in a split-plot model. At the plots were allocated the periods and at the sub-plots the combination of three levels of nitrogen and two grazing intensities (High mass and Low Mass), making six treatments in a factorial scheme. The levels of nitrogen used were composed of 0, 200 and 400 kg of N.ha-1 and the grazing intensities characterized by the low forage mass (LM) with 1.500 kg of DM.ha-1 and high forage mass (HM) with 3000 kg of DM.ha-1 in a continuous stocking rate. Were used goats half blood Boer with five months old and average life weight of 21 kg of live weight (LW) at the beginning of the experiment with the aim to adjust the forage mass (FM) wanted. Was evaluated the accumulate and total forage production of the papuã aerial biomass at the experimental periods, the nutritional indices of nitrogen, phosphorous and potassium and also the dilution curve,
efficiency of N recovery and behave of nitrogen in the soil. The Brachiaria
plantaginea forage production was higher at the nitrogen intermediate level (200 kg
of N.ha-1), reaching an production of 19.834 kg of DM.ha-1, 31% more then treatment
without nitrogen. The N levels found in the plants that received nitrogen fertilization
showed higher values than the ones recognized as deficient, resulting in adequate contents of this element in the plant and, in the other hand, the plants cultivated without nitrogen showed levels below the one recognized as sufficient, showing with that the dilution curve of N is an adequate tool to diagnose the forage nitrogen nutrition. The highest production was limited by the lack of phosphorous showed by the phosphorous indices obtained according to the pasture element levels and the absorption of K increased with the nitrogen application, showing satisfactory level of the element. The 200 level of N.ha-1 showed to be the most efficient with recovery N levels 63% higher than the 400 kg.N.ha-1. There was no inorganic (NO3
- e NH4 +) N leaching found in the soil profile and was noticed higher quantities of NO3 - and mineral-N at the lower forage mass after finishing the total N applied. |
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