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ARS Home » Pacific West Area » Pullman, Washington » Northwest Sustainable Agroecosystems Research » Research » Publications at this Location » Publication #90623


item Kennedy, Ann

Submitted to: Biological Agriculture Horticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: Practitioners of biodynamic agriculture have claimed that the biodynamic preparations increase microbial activities in composting and yield a better product, yet reliable scientific investigation of this claim is scarce. This study examined the effects of biodynamic compost preparations on the maturation of compost from farm waste. The biodynamic preparations are fermented herbs and minerals, used in very small amounts as additions to compost and as field sprays on biodynamic farms. Six of these preparations (numbered 502 through 507), when added to composting dairy manure and bedding, caused consistent changes in the developing compost. Biodynamically treated composts showed higher temperatures, faster maturation, and more nitrate than composts that had not received the biodynamic compost preparations but had received an inoculation of field soil. This research impacts farmers, particularly livestock farmers, who recycle their farm wastes as fertilizer. This research also impacts industrial composting and bioremediation companies. The findings of this research support the idea that use of the biodynamic compost preparations could speed the composting process, better destroy pathogens and weed seeds in the material by maintaining high temperatures longer, and change the value of the resulting compost as a fertilizer by increasing the amount of nitrate.

Technical Abstract: Biodynamic (BD) compost preparations 502 through 507 were applied to compost piles made of dairy manure and bedding. Alternate piles received the same additions of soil and water as biodynamic piles received, but no biodynamic preparations. Biodynamic-treated composts maintained higher temperature throughout the period of active composting and reached chemical stability at an earlier time than untreated composts, suggesting faster development of mature compost with biodynamic treatment. At the end of the active composting period, when the piles entered a ripening stage, the biodynamic-treated piles showed higher dehydrogenase activity, lower CO2 release, and thus a higher ratio of dehydrogenase / CO2. Finished composts were similar in all measurements, except that biodynamic-treated composts had 65% more nitrate.