Unlikely Riches

Manure is a highly valuable soil additive for nutrients and organic matter.

What is the value of a load of manure? I often smile when I think about describing my work to people. Writing manure management plans, designing manure storage facilities, taking manure samples, calibrating manure spreaders – sounds like a crappy job! Working with farmers to improve management, stewardship, and profitability is actually pretty sweet.

Why is all this attention given to manure? Because it’s a valuable resource. Most agricultural land in Bradford county is low in the fertility necessary to produce a profitable crop. Manure is the most preferred additive because of its many soil benefits, namely nutrients and organic matter. All growing plants need nutrients while organic matter supports the living soil creatures that make nutrients available. Soil pH is another major indicator of soil productivity.

The major nutrients needed for healthy crop growth are nitrogen, phosphorus, and potassium. For a field to produce four tons of dry hay in a year, each acre of soil will need to provide 200 pounds of nitrogen, 60 pounds of phosphorus, and 200 pounds of potassium. If this is not already in the soil, then farmers look for ways to add it. The most common options are manure and commercially produced fertilizers in dry and liquid forms. This can be expensive and is a major factor in farm profitability.

How these soil additives are managed can also impact natural resources of interest to the larger community, like air and water. Farmers have a weighty responsibility in feeding us while we expect them to do it in an environmentally responsible manner. We need to be ready to adequately appreciate them for it.

Let’s just say that a typical load of manure weighs five tons. On average this might contain 50 pounds of nitrogen, 20 pounds of phosphorus, and 40 pounds of potassium. When considering the cost of nutrients commercially, this load of manure is worth $43 simply for its nutrients not counting the other soil health benefits it has over commercial fertilizers.

If I spread this manure on a field at a rate of 20 tons per acre (4 loads spread over one acre), I will have given this field about a third of the nitrogen it needs (all is not available to plants immediately), about ¾ of the potassium requirement, and a little excess phosphorus. In most Bradford County farm fields, phosphorus levels are significantly low, so applying some excess beyond crop needs is good to build soil levels. When nutrient levels are optimum, applying excess becomes a poor use of valuable resources and can have detrimental effects in the watershed.

Every farmer, especially these days, wants to make good use of $43. A typical Bradford County dairy farm may manage approximately $17,000 worth of manure nutrients each year. You can see why they care to make good use of every pound, finding value in unlikely places.