Value of Manure in Landscapes is Not Just for Fertilizer

Q. What is the range of N-P-K value in cow manure that I see some landscapers use for grass?

Manure can be a valuable source of many different plant nutrients, good and bad microorganisms, 

and organics. It is best composted first but in a pinch you can use it raw. Just be careful.

A. The fertilizer content (N-P-K value) of steer or cow manure varies because of what they eat and how the manure is collected and processed. It is considered “low” in fertilizer content as far as fertilizers go. It would take a very small amount of bagged fertilizer to equal the fertilizer content in a ton of manure. Both manures contain about 4% nitrogen and lesser amounts of phosphorus (P value) and potassium (K value). They can both be high in salts and rich in both good and bad microorganisms.

Difference Between Cow and Steer Manure

There is a difference between steer and cow manure. Cow manure is typically derived from cows used for dairy farming. Steer manure is derived from cows fed for meat production. Steer manure typically contains more salt than cow manure and it is considered “hotter” when applying it to plants.

Value of Manure

The value in manure is due more to its potential for soil enrichment rather than its N-P-K content.  For that reason, it can be mixed into a “hot” compost pile. The heat from these compost piles will help to change the microorganism content and decrease or possibly eliminate those microorganisms which are a potential human health problem. 

Research has shown that applications of composted manure can reduce lawn diseases due to its high microorganism count. Application of dry manure is done best with a barrel-type compost spreader.