Effect of different fertilizer treatment (N,P,K) on production of superior at four year short rotation system

Superior varieties of poplar wood production in 2,3 and 4-year short rotation systems have wood production efficiency many times as much of the customary systems. In the method, because of continuous harvesting, maximum use of the area unit and high produced biomass, soil is involved with organic and minerals shortage and if it not to be supplied, it will be expected reducing of the production in the fallowing rotations. In order to determination of the the best and most suitable combination of the chemical fertilizers and investigation of the effects of the fertilizers on the growth traits, it was performed an expriment using three superior clones of the short-term operating system ( Pe triplo, Pe 561/41, Pd 69/55) and 27 different combinations of the nitrogen, phosphorus and potassium fertilizers as a factorial design with three replications. In order to make equalation of the growth condition for the seedlings, it was applied no fertilizer treatment in the first year. At the end of the first year, all of the seedlings were cut off from the ground to lead to grow multiple and strong trunks. Fertilizer treatments were applied in the second growth year. Growth traits such as diameter, height, volume and number of the trunks were measured in the end of the each growth season. After three years, the results indicated that: - There were significant differences in diameter, height and volume between the poplar clones in every three years. Clone deltoids 69/55 was always superior of the clones. - Further amaunt of the nitrogen and phosphorus caused significant differences in the height and diameter of the clones. - In the second year, the significant difference was only obsorved in the highst nitrogen application. - In the third year of the experiment, none of the compounds were caused significant differences in the growth traits of the poplar clones.