IMPACT OF GENOTYPE AND NITROGEN FERTILIZER RATE ON YIELD AND NITROGEN USE BY OAT (Avena sativa L.) IN TURKEY

Efficient nitrogen (N) use is one of the most crucial issues for crop management in developing countries. Since Turkish agricultural practices tends to use lower inputs of N fertilizers, a field trial was carried out in 2007-08 and 2008-09 cropping years to determine response of six oat genotypes (Seydisehir, Apak, Yesilkoy-330, Amasya, Checota and Yesilkoy-1779) to three N rates (0, 100 and 200 kg ha(-1)). According to the results, differences between the years were significantly important for all investigated traits except soil nitrogen content at planting (NCP), nitrogen content at maturity (NCM) and nitrogen accumulation in grain (NAG). Genotypes significantly varied for all traits except NCP, nitrogen in grain (NG) and NAG. However, differences among N rates were significant for all traits except NCP.Among the genotypes Checota had the highest nitrogen use efficiency (NUE) and grain yield (GY) (20.6 kg kg(-1) N and 2590 kg ha(-1), respectively).