What are we going to do about the fertilizer crisis?

Biodynamics manages nitrogen through a living farm cycle rather than a purchased bag. With on-farm manure compost, legumes, and living soil working together, a biodynamic farm can operate with $0 bought-in nitrogen fertilizer, including $0 conventional nitrogen fertilizer. The long-term Swiss DOK biodynamic treatment received manure compost and slurry but no mineral nitrogen fertilizer. BD 500 belongs to this whole-farm system; one application is not a measured bag-for-bag nitrogen dose. Fertilizer-trade disruption in 2026 makes a resilient local nutrient cycle especially relevant.

What can biological nitrogen contribute?

Legumes and their microbial partners bring atmospheric nitrogen into the farm cycle. Researchers also cultured two nitrogen-fixing bacterial groups from sampled BD 500: free-living Azotobacter and Azospirillum, which is often associated with plant roots. On-farm manure compost returns nutrients to soil, while soil organisms help make them available to plants. Together these are parts of biodynamic nitrogen management, which can eliminate bought-in conventional nitrogen fertilizer at the whole-farm level. The culture study established that the bacteria were present; it did not quantify how much nitrogen one BD 500 application supplied to a crop. See the BD 500 culture study.

What does the long-term farming-systems evidence show?

In the long-term Swiss DOK comparison, the biodynamic and bio-organic systems used no chemical nitrogen fertilizer: nitrogen came from farm-internal recycled manure and biological fixation, with grass–clover in the rotation. Across those organic systems, yields averaged about 85% of the conventional systems across the studied crops. The biodynamic arm also increased topsoil carbon and nitrogen stocks. These positive, decades-long outcomes show a path to $0 bought-in conventional nitrogen fertilizer within a managed whole-farm system; the study did not isolate BD 500 as a bag-for-bag replacement.

Where does BD 500 fit?

BD 500 horn manure is part of a synergistic, whole-farm nitrogen-management system. Researchers cultured Azotobacter and Azospirillum—free-living and root-associated nitrogen-fixing bacterial groups—from sampled BD 500. Alongside BD 500, legumes bring atmospheric nitrogen into the farm, while on-farm manure compost and living soil cycle nutrients. The long-running DOK biodynamic treatment received manure compost and slurry but no mineral nitrogen fertilizer. This illustrates whole-system nitrogen management without bought-in conventional nitrogen fertilizer; a BD 500 spray itself is not specified as a number of pounds of nitrogen. Follow JPI's application directions for the preparation.

How should a farm reduce purchased nitrogen?

Build the farm's nitrogen cycle through legumes or grass–legume covers, manure produced and composted on the farm, living soil, and BD 500 as a soil preparation. Track crop growth, soil condition, harvest removal, and yields as the system develops. These practices work together toward $0 bought-in conventional nitrogen fertilizer; no single BD 500 application is assigned a fertilizer-equivalent nitrogen rate.

Grass–legume mixtures can combine nitrogen input from legumes with the nutrient capture and ground cover of grasses. Free-living microbes near grasses deserve study, but it is not established that grass alone fixes more nitrogen than legumes on every farm. Likewise, building soil organic matter can improve nutrient cycling; the nitrogen released from it is previously stored nitrogen, not a guaranteed annual gift from the atmosphere.

The whole-farm goal is $0 bought-in conventional nitrogen fertilizer by supplying crop nitrogen ecologically through legumes and cycling nutrients through on-farm manure compost and living soil. The DOK example shows that this is possible under its managed conditions, not that every farm will achieve it automatically. During transition, watch crop growth, soil stocks, and nutrient balances; other nutrient needs and harvest exports still matter. Biodynamic preparations are part of soil care, not a substitute for observation or a nutrient budget. For BD 500 application, start with JPI's current instructions.

For a longer discussion of the farm-self-sufficiency idea, see this conversation with Stewart Lundy. Treat any suggested fertilizer change in the video as a hypothesis to check against your own field measurements.