The Value of Wheat Straw

August, 2019

The Value of Wheat Straw

We are looking at heavy crop residues in much of our crops in the Peace Region this fall. The value of that crop residue is often forgotten when considering whether to chop, till, bale or burn. All a person can think of is the issue of seeding through the heavy mat of crop residue in the spring. While I do not have the value of all the different crop residues, I have found a recent article in the North Dakota State University Agricultural Newsletter that puts a value on wheat straw. The following contains excerpts from that article.

Wheat straw contains some of all essential plant nutrients, but nitrogen (N), phosphorus (P) and potassium (K) are the only nutrients in sufficient amounts to be considered. Wheat straw contains some of all essential plant nutrients, but nitrogen (N), phosphorus (P) and potassium (K) are the only nutrients in sufficient amounts to be considered. There is also calcium and magnesium in similar amounts, but all regularly cropped and productive soils in North Dakota have very large amounts of each of these, so they are not considered a value that needs to be considered in the fertilizer value of the wheat straw.

Generally, there are about 13 lb N per tonne, 1.7 lb P 2 O 5 (phosphate fertilizer equivalent) and 33 lb K 2 O (potassium fertilizer equivalent) in a tonne of straw. At present day local retail fertilizer price estimates, the value of these is:

N (13 lb) at $.23 per lb ($515/tonne) = $ 2.99 P 2 O 5 (11.7 lb) at $.31per lb ($680/tonne) = $.53

K 2 O (33 lb) at $.23 per lb ($510/tonne) = $7.59 Total fertilizer value = $ 11.11 / tonne

The average straw yield per acre from a 60-bushel crop of wheat would be from 1.5 to 2.0 tonnes (3,000 – 4,000 lbs) per acre. Using these yields, with the strike of a match or hauling off crop residue for livestock, you could be losing;

$2 667 - $3 555 per quarter section

Eastern growers (Stutsman county and east) have grown soybeans especially, and also corn, for more than 20 years and have depleted their native potassium supply. The new corn potassium recommendations result in a higher soil test critical level (200 ppm instead of the old 150 ppm recommendation in highly smectitic clay soils) to sustain corn production in drier summers. However, western growers have very high K tests as a rule. Many western fields have soil test K levels over 400 ppm, and these growers probably would not put a value on the K since they do not consider K in their fertilizer budget, except as a carrier for chloride. Eastern growers have to consider the K value of the straw or experience decline of soil test K requiring fertilization. Failure to do so will result in yield losses in alfalfa, sugar beet and corn production particularly.

The historical use of the land could also affect how you value crop residues and the above calculation on value does not account for other benefits. Other benefits, such as improved soil health from keeping the soil covered, moisture conservation, erosion reduction, and wildlife habitat, to name a few are things you may consider based on your own ideology and values.

This article contains excerpts from:

• Dave Franzen, Extension Soil Specialist

North Dakota State University https://www.ag.ndsu.edu/cpr/soils/the-value-ofwheat-straw-07-25-19

• and Shelleen Gerbig, P.Ag., SARDA