Effect on Soil Chemical Properties

The long-term soil amendments caused significant changes in soil physical-chemical properties (Table 1). Soil bulk density and pH were significantly (p < 0.05) lower in the two compost plots than in the control plot. Moreover, soil pH was significantly (p < 0.05) lower in the EM compost plot than in the traditional compost plot. Soil organic matter, total N, alkaline-hydrolysable nitrogen, and available K content was significantly (p < 0.05) higher in the two compost plots than in the control plot. Soil available P and K content was significantly (p < 0.05) higher in the EM compost plot than in the traditional compost plot.

Another trial (Lim, Pak, & Jong, 1997) conducted in Korea, looked at the effect of EM treatment on the content of nutrients in the soil. The EM treatment increased the content of soluble nutrients. The contents of soluble nitrogen, phosphorous and potassium increased 4.4, 3.6 and 2.8 mg/100g soil, respectively. The increase of soluble N, P and K contents might be attributed to activity of nitrogen fixers and organic acids excreted by the different organisms in EM. 

Lim, Y. D., Pak, T. W., & Jong, C. B. (1997). Yields of Rice and Maize as Affected by Effective MIcroorganisms. Institute of Agrobiology and Institute of Soil Science, Academy of Agriculural Sciences.