Compost tea production methods affect soil nitrogen and microbial activity in a northern highbush blueberry system

The use of compost tea has increased in organic agriculture as a substitute for herbicides and inorganic fertilizers, but the relative effects of compost tea produced via different methods are largely unknown. We examined the effects of compost tea on soil and plant chemistry and microbial community enzyme activity on an organic blueberry farm in Minnesota, USA. We randomly assigned plants to one of three compost tea treatments: aerated compost tea under ambient temperature, heated and aerated compost tea, and a control treatment. Heated and aerated compost tea increased soil percent nitrogen compared to the other treatments, and decreased activity of β-1,4-N-acetylglucosaminidase, an enzyme involved in chitin degradation, compared to the aerated-only treatment. We propose that the production method of compost tea has a significant effect on its efficacy as an organic soil amendment.