Effects of Fertilization on Seed Production in oat (Avena sativa) on the Tibetan Plateau

Being a forage grass with high nutrient value,oat(Avena sativa) is well adaptive for the climatic condition on the Tibetan Plateau.Low seed production of oat on the Tibetan Plateau was found due to high altitude and hard climatic condition.Nitrogen fertilizer application affected both seed yield and quality.Protein content of seed had a highly positive liner correlation to nitrogen level(R=0.896 8,P0.01).Available tillering and spikelet numbers,yields fro forage and seed showed a quadratic regression relationship to fertilization level(P0.01).The highest seed yield(4 358.5 kg/hm2) gained at application rate of N 6 kg/hm2.N fertilizer rate over 60 kg/hm2 did not produce positive effect to seed yield,but decreased output to input ratio.It suggested that ideal nitrogen fertilizer rate for oat seed production was N 60 kg/hm2 and 75 kg/hm2 for forage production.