The effect of nitrogen fertilization of permanent pastures on seasonal distribution of yields and on nitrogen recovery in the herbage
1942
Robinson, R.R. | Pierre, W.H.
Studies were conducted over a 7-year period of the effect of nitrogen fertilizers on the yield, seasonal distribution of yield, and percentage of the fertilizer nitrogen recovered in the herbage from clipped plots in permanent pastures. Although summer applications of nitrogen did not give satisfactory increases in yield during the summer unless soil moisture was adequate, the plots that received part of the nitrogen during the summer produced about the same total yield during the 7-year period as the plots that received all of the nitrogen in the spring. This favorable response to summer applications of nitrogen was obtained at each of two rates, namely, 100 and 200 pounds of nitrate of soda per acre per year. These results indicate that summer applications of nitrogen may have a definite place in a program of intensive dairying. During favorable summers, the nitrogen would help to maintain uniform pasture during the season. During unfavorable years, the effect of the nitrogen would be carried over until growing conditions became more favorable. The values for percentage nitrogen recovery ranged from plus 92 to minus 51, with an average of 21 for one pasture and 25 for another. These differences were discussed in relation to the season, the botanical composition of the pasture, and the fertility level of the soil.
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