ABSTRACT
EVALUATION OF NITROGEN FIXATION BY A MIXED RED CLOVER-ORCHARD GRASS PASTUrRE IN THE SOIL SERIES "SANTIAGO"

Elías Letelier A.1 y Maximiliano Martínez V.1
 
By using data from a long term rotations x fertilization experiment carried out at La Platina Experimental Station, the simbiotic fixation of nitrogen made by a Trífolium pratense-Dactylis glomemta pasture has been calculated; this has been accomplished by estimating the nitrogen extracted from the soil by the pasture and by the erops. Considering that only in the two first years of the sward there was clover in significant amounts, the balance indicates a fixation of 322 Kg of N in each of this two first years. From the 644 Kg fixed in these two years, 233 are transfered to the following crops. A very similar figure of transference of N to crops was obtainded by an estimation based in the yields of the crops with and without added nitrogen.
Keywords:
1Ings. Agrs., Programa Ecología y Manejo. lnstituto de Investigaciones Agropecuarias, Estación Experimental La Platina (INIA), Casilla 5427, Santiago, Chile.