Toxicity

• Uncomposted manure may have pathogens, such as E.coli or Salmonella, that are dangerous for humans. These pathogens may pollute food crops, potentially causing serious illness. Vegetable seeds grown directly in steer manure may be at greater risk of contamination than those grown in soil amended with manure. Amend vegetable garden soils with 2 to 3 inches of steer manure and compost at least 120 days before harvesting food crops to prevent illness. Manure must be heated to at least 131 degrees Fahrenheit for 15 days while composting to kill pathogens. Additionally, raw manure can burn crops when applied to the garden. Seeding plants directly in steer manure may cause plant damage.
  
  

Cost and Availability

• For most gardeners, high-quality compost and steer manure is a precious commodity, much less available and more expensive than garden soil. Even if you compost at home and have access to free manure, chances are you'll want to conserve those resources by using them as an amendment, rather than a planting medium.
  
  

Salinity

• Steer manure is usually high in salts, and composted manures are typically higher in salt than raw manures. Planting seeds in steer manure and compost may cause reduced rates of germination, leaf burn or reduced vigor, due to the high salt levels.
  
  

Texture

• Many potting mixes contain a combination of compost or manure, perlite, peat moss and vermiculite without the addition of soil. These soil less mixes are weed and disease free, but have the necessary ingredients for good drainage, moisture retention, and light texture that seedlings need to thrive. Compost and steer manure alone has a lightweight texture and drains well, but doesn't hold moisture. Use it as an amendment in the garden, or as an ingredient in homemade potting mix.