COLUMBIA, Mo. — With forage in short supply due to drought, some livestock producers are looking at wheat straw as feed despite its poor nutrient quality.
This leaves wheat farmers asking what the value of their wheat straw is, says University of Missouri Extension agricultural economist Ray Massey. Massey and agriculture economist Joe Horner developed a spreadsheet to help producers decide. Download it at http://muext.us/WheatStrawValue.
Several considerations determine the real cost and value of wheat straw, Massey says in an Extension news release. First, what nutrients leave the field when straw is baled? What are the effects on organic matter in the soil? Are there negative effects from soil compaction to the wheat field?
It is easiest to estimate the cost of nutrient removal. Massey recommends using published book values such as those from the International Plant Nutrition Institute, at tinyurl.com/56bc6dcb, on the quantity of nitrogen, potassium, phosphorus and sulfur in the straw to estimate the market value to replace removed nutrients with commercial fertilizers. Multiply the amount of nutrient by the value of the nutrient to estimate the value of the straw. Book values may vary by state.
When considering the value of straw to the soil’s fertility, look at the nutrient’s stability, Massey says. Phosphorus and potassium are stable nutrients that, if removed in the stubble, likely reduce soil fertility.
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On the other hand, nitrogen content of the straw may have less effect on soil fertility since it is a volatile element. If left on the surface, it may not be available to later crops. Valuing nitrogen may overestimate the cost of replacing the nutrients removed by harvesting the straw.
Massey gives the following example:
A farmer has wheat straw that can be baled and sold. Book values show that every ton of wheat straw contains 15 pounds of N, 3.7 pounds of P2O5, 29 pounds of K2O and 5.4 pounds of S. Local fertilizer prices indicate nutrient prices of 49 cents per pound for N, 69 cents per pound for P2O5, 52 cents per pound for K2O and 82 cents per pound for S.
If nutrients removed affect soil fertility, the total value of nutrients removed equals $29.32 per ton. However, this values all the N in the straw. If all the N in the straw adds nothing to soil N, the N in the straw would not be valued and the total value of nutrients removed becomes $22 per ton.
If the farmer is the person baling the hay, consider adding a custom baling charge to the value of the nutrients removed. If baling costs are estimated at $18 per bale and each bale weighs 1,200 pounds, the value of the straw now becomes $52 per ton ($22/ton for nutrients plus $30/ton baling charge).
Business transactions for creating a profit margin should reward the farmer for the risk and management of the activity. If the farmer wants 15% margin for profit and risk, the value of the straw becomes $59.80 per ton ($52/ton x 1.15 for margin).
“The process above tells the wheat farmer what the soil nutrient value of the straw is,” says Massey. “It does not tell the livestock farmer the feed value of the straw.”
The livestock farmer should research the feed value of the straw to ensure that it exceeds the price the wheat farmer is asking for the straw.