Effect of nitrogen application on nitrogen absorption,distribution and yield of Strawberry

Pot experiments were conducted to examine the effects of nitrogen application time and rate on nitrogen absorption and distribution using labeled(15N) isotope technique.The treatment applying N at fix planting and before anthesis with half dose got the highest nitrogen utilization rate equivalent to 52.5%;while the nitrogen utilization rate of the treatment applying N before anthesis with full dose was the lowest being 34.2%.The ratio of N-distribution in various organs existed significant difference when fertilizer was applied at different stages.The ratio of N-distribution of nutritive organs to genital organs was 5.7 to 1,while the ratio was 2.6 to 1 when N was top addressed with half dose at fix planting and before anthesis.Top addressing N before anthesis could increase the N distribution rate of genital organ significantly(equivalent) to 31.3%. By all appearances,the absorption and distribution of(15N) were transfused with the change of organic centre of strawberry.The competition ability of genital organs on(15N) at the later growing period was higher than nutritive organs.Field test results indicated nitrogen application influenced significantly nitrate concentration and SPAD reading of ripe leaf.Applying N with dose of 225 kg/ha by means of top addressing at fix planting and before anthesis with half dose separately could accelerate blossom buds differentiation and get the highest forepart and total yield of strawberry.