INFLUENCE OF NITROGEN FERTILIZER APPLIED IN WINTER ON ALFALFA YIELD AT THE FIRST CUTTING IN SPRING

Some growers feel that nitrogen (N) fIXing nodules found on the roots of the alfalfa plant are ineffective in cold soil during the winter and early spring. Thus, starter N fertilizer is commonly applied in late winter to established alfalfa to enhance growth until spring when the soil warms up and alfalfa begins actively fIXing atmospheric Nz. Established alfalfa normally does not benefitfrom applications of N fertilizer since it is a leguminous crop that is capable of fIXing its own N from atmospheriC Nz. Afield experiment was conducted to determine the effect ofN fertilizer applied in winter on alfalfa hay yield at the first cutting in spring. Two treatments consisted of an unfertilized check plot and VAN 32 water run at a rate of35lbs. N/acre to three year old 'CVF 101 ' alfalfa grown on a silt loam soil testing deficient in nitrate-No Maximum alfalfa hay yield (J tonlacre) was obtained at the first spring cutting without N fertilizer application. However, since thefield has a known yield potential of 1.5 toniacreJactors other than fertility influenced the alfalfa hay yields observed in this study