FERNÁNDEZ GRECCO, R.¹
In the Buenos Aires’s Depressed Pampas, tall wheatgrass Thinopyrum ponticum (Bark and Dewey) pastures are usually considered crops that concentrate growth during late spring to midsummer, with poor forage production and of low nutritional value for animal production. We conducted two trials at the EEA INTA Balcarce on a tall wheatgrass pasture in order to evaluate the effect of nitrogen fertilization on the dynamics of growth and accumulation of forage during two seasons: autumn-winter and spring. We used 6 doses of nitrogen (DN) N0 to N250, with increments of 50 kgNha-1 and we used urea as nitrogen source. The winter period extended from May 18th to September 3rd, while in the spring evaluations were conducted between August 28th and December 4th. In both periods forage accumulation showed significant differences (p <0.05) to the addition of N. Maximum values were recorded during springtime (6200 kg DMha-1), with growth rates of 84 kg DMha-1day-1, while in winter the maximum achieved value was 4600 kg DMha-1 with maximum growth rates of 43 kg DMha-1day-1. The results obtained show that wheatgrass pastures may increase the forage accumulation through proper
mineral nutrition in both seasons.
Keywords: tall wheatgrass, fertilization, nitrogen, winter, spring.