Effects of Vermicompost and Chemical Fertilizers on Phonological and Phytochemical Traits of Soybean (Glycine max L.)

Abstract One of the basic principles of sustainable agriculture is the use of organic fertilizers in agricultural ecosystems with the purpose of eliminating or substantially reducing the use of chemical inputs. To evaluate the effect of different amounts of vermicompost on some phonological and phytochemical traits of soybean, an experiment was conducted at Agriculture and Natural Resources Research Center of Shahrekord in 2013. The experiment was conducted in a randomized complete block design including vermicompost treatments (10, 20, 30, 40 and 50 ton.ha-1), chemical fertilizer based on soil testing analysis in the amount of 300 (kg.ha-1) (N.P.K: 20.20.20), and control (no fertilizer). The results showed that 40 ton.ha-1 vermicompost had a positive and significant effect on the soybean phonological stages, the content of chlorophyll a and b and carotenoid. Significant reduction of the required GDD from planting to germination, flowering, and pod stage, but required GDD was observed from increased the pod stage to full maturity was significantly increased. In addition, the chlorophylls a and b content and carotenoid were increased in comparison with control treatment. It appears that due to the positive effects of organic fertilizers on soil physical and chemical properties and gradual releasing of the soil’s required elements along with the high capacity of the humidity perseverance, they can be appropriate alternatives for chemical fertilizers.   Keywords: Soybean, Vermicompost, Photochemistry, Phonological, GDD, Chlorophyll a and b, Carotenoid