Influence of Nitrogen Fertilizer Application Techniques on Winter Wheat (Triticum aestivum L.) Growth in Lorestan Province

In order to evaluate the effect of different nitrogen application methods on yield and yield components of winter wheat, a field experiment was conducted with split plot arrangement in completely randomized blocks with four replicates in 2006. Basal N was applied at three levels (no basal dressing, band application, and surface distribution) in the main plot. In the sub-plots, top dressing was applied at six levels (1-at tillering only, 2-at tillering and before spike appearance, 3- foliar application with herbicide application before spike appearance, 4-two foliar application at tillering and before spike appearance, 5-two application: at tillering and one foliar application before spike appearance, 6- three foliar application at tillering, before spike appearance, and at milking stage). The amount of fertilizer in strip application was 2/3 of distributing method. In the split application, the amount of applied fertilizer was two third of that used in the broadcasting method. Based on fitted peak equations, the maximum leaf dry matter estimated for no basal nitrogen fertilizer treatment was 30% lower than the mean of maximum leaf dry matter estimated for band and broadcasting application of basal nitrogen fertilizer. Band and broadcasting application of basal nitrogen fertilizer increased leaf dry matter per plant 46 and 64%, respectively, in comparison to no basal treatment. Basal nitrogen application, band or broadcasting, increased wheat stem dry matter by 31%. The highest stem dry matter per plant recorded for one top dressing at tillering (2/3 traditional treatment) plus one foliar application before spike appearance, that was 27.6% higher than traditional treatment. Wheat tiller number for broadcasting and band application of basal N was significantly higher than that for no basal nitrogen treatment by 20.5%. Top dressing at tillering (2/3 traditional treatment) plus one foliar application before spike appearance had the highest tiller number and flag leaf dry weight.