Ask HN: Biodegradable electronic tracking

Are there any start-ups operating in this space or someone know of products that meet these general requirements:

Biodegradable (one time use) | Cheap (must scale to millions) |Easy to connect to mobile devices

Example--tracking individual cabbage plants (millions +) by embedding some chip (RFID?) when seedlings are planted. Each cabbage plant can then be hand-harvested and traceable to the consumer.