Characteristics of E.coli Loss under Different Fertilization of Manure

Abstract

Approximately 90 million tons of dung is produced annually from cattle farms all over Japan. Considering the proper treatment of this waste product, applying manure to farmlands has been focused from a viewpoint of popularizing organic agriculture. However, pathogenic bacteria known as E.coli may possibly be released from the immature fermented manure that was applied in farmlands. In this study, model experiments were conducted employing slope plots under artificial rainfall simulator to investigate the E.coli loss. The slope plots were filled with soil and then applied 3 types of manure such as cow dung, manure fermented for 2 weeks and for 12 weeks. Additionally, two methods of application were proposed such as broadcasting method and incorporating method to differentiate the loss of E.coli from farmlands applied manures. The experimental results showed the amounts of E.coli loss by the broadcasting method were significantly higher than that by the incorporating method in the plots applied cow dung. Also in both methods, surface runoff showed higher amounts of E.coli loss compared to percolation. In addition, there was a tendency the loss of E.coli decreased with fermentation stage of manures. Therefore, it was concluded that the loss of E.coli, being affected by the fermentation stage of manure, was remarkably influenced by surface runoff in both broadcasting and incorporating methods.