Effect of Application Methods of Vermicompost and Chemical Fertilizers on Tuber Yield and Some Morphological Traits of Potato (Solanum tuberosum)

To investigate the effect of vermicompost, chemical fertilizers and their application methods on tuber yield and some morphological traits of potato (Agria cultivar) an experiment was carried out in Mahidasht Agricultural and Natural Resources Research Center in Kermanshah Province during 2012-2013 cropping season. The experiment was carried out in a split plot factorial using a randomized complete block design with four replications. Levels of vermicompost (0, 1.5, 2.5, 3.5 t/ha) were assigned to main plots, and chemical fertilizers with three levels (0, 50 and 100 % chemical fertilizer recommended) of the amount of 225 kg/ha of urea, 150 kg/ha of potassium sulfate, 105 kg/ha of triple super phosphate and 52 kg/ha zinc sulfate and on 50% level respectively 112.5, 75, 52.5 and 26 kg/ha and fertilizer application methods at 3 levels (broadcast, one band and two band application) to subplots. The results showed that increasing the amount of vermicompost about 3.5 t/ha and reducing chemical fertilizer by 50% and applying it in two band increased plant height, number of stems per plant and tuber yield. The highest tuber yield was obtained from application of 3.5 t/ha of vermicompost, 50% chemical fertilizer and two band fertilizer applications (37 t/ha). This study indicated the positive effect of vermicompost on potato tuber yield. Thus, it can be suggested that combined application of chemical fertilizers and organic fertilizers may reduce chemical fertilizers usage and reduce also the environmental pollutions.