Crescimento, desenvolvimento e qualidade nutricional de cultivares de aveia branca sob níveis crescentes de nitrogênio cortadas em intervalos fixos

Abstract

The Southwest region of Paraná presents the well-developed agrarian sector, with emphasis on dairy production from family farming. The nutritional base of these properties are pastures formed by tropical grasses, which present a decrease in their phytomass production at a given time of year, with the decrease in luminous intensity and temperature. The implementation of temperate pastures, mainly of oats, is a common strategy in the region for the activity. The effects of nitrogen levels on growth, development, phytomass accumulation, chemical composition, ruminal kinetics and greenhouse gas production were evaluated. The work was conducted in UTFPR-DV in the years of 2013 and 2014, in randomized blocks with four levels of N fertilization (0.60, 120 and 240 KgN.ha-1) with 3 replications, in cut-off times every 21 Days, using white oats (Avena sativa L.) URS Guapa and IPR126. Were analysed CO2 assimilation rates, intracellular CO 2 concentration, transpiration rate, leaf temperature, chlorophyll content, phytomass production, protein, NDF, lignin, EE, gas production in relation to fast-degraded carbohydrate. In the year of 2013, there was a significant effect on the variables PB, CT, k1, water use efficiency, transpiration and foliar temperature, while for the year 2014, Variables were CT, vf1, k1, vf2, number of tillers and water use efficiency. For the cultivar URS Guapa, in the year 2013, there was a significant effect for the variables leaf weight (in grams) and leaf tempreture, while in the year 2014, number of tillers, transpiration and leaf temperartura were significant. It was observed that The cultivar IPR 126 was more influenced by levels of fertilization than the cultivar URS Guapa, in all years and greenhouse gases were not affected.