Skip to main content

The Value of Wheat Straw

Current economics may have you ponder whether it’s worth selling the straw to generate extra income from your wheat acreage. To put a value on something, we generally look at the marketplace and let supply and demand determine the value of the goods in question. To determine the value of straw, we can look at local or regional hay auctions to get an idea of what livestock producers are willing to pay.

However, we could also look at it from a different angle. Opportunity costs are defined as the costs of using a resource based on what it could have earned if used for the next best alternative. One way to determine the value of straw left in the field is to look at the nutrients that are available in the straw. There are several online tools available to estimate the amounts of N, P, and K that will be removed if the straw is bailed.

Removing straw does not necessarily mean that you will mine your soils. Only if the amount of nutrient removed is greater than the amount of nutrients applied, will you mine the soil. You can estimate how much you are mining by subtracting the total amount of nutrients removed in the grains and straw from the amount of fertilizer applied. For every bushel of wheat, you can assume that you will produce somewhere between 70 to 85 lbs. of straw. This estimate will be closer to the lower end of the range with shorter varieties and/or when grain yields are high and closer to the upper end of the range with taller varieties and/or when grain yields are low. The amount of N, P, and K removed in straw are listed in Table 1. For a 50 bushels wheat crop, you will remove about 2 ton of straw. This is equal to 28 lbs. of N, 6.6 lbs. of P2O5, and 48 lbs. of K20 or about $ 30.00 per acre. This does not account for the additional time, labor, and hauling costs.

Table 1 - Pounds of N, P, and K removed per 2000 lbs. of wheat straw.
Nutrient removal Estimated cost of
Opportunity cost of
nutrient removal
(per 2000 lb of straw) (per 2000 lb of straw)
N 14.0 $0.41 $5.74
P2O5 3.3 $0.35 $1.16
K2O 24.0 $0.32 $7.68

Wheat straw doesn’t just remove nitrogen, phosphorus, potassium but also small amounts of micronutrients and carbon. While applying fertilizer can replace all these different nutrients, it will not replace the carbon that is removed. Soil Organic Matter (SOM) is roughly 50% carbon. Quantifying the value of SOM is more difficult that the calculations for nutrient removal. Higher SOM levels mean better soil aggregation, improved water infiltration, better trafficability, less erodibility, and a generally higher level of productivity due to more available water and nutrients.

Each percent decrease in SOM equates to about a 1-inch decrease in water holding capacity, about a loss of 1,000 lbs. of N, and decreases in the availability of P and S. Soil carbon levels are maintained by returning residue to the soil, rotating crops with pasture or perennials, or by adding organic residues such as animal manure, green manure, or sewage sludge. Removing straw doesn’t immediately result in loss of SOM as you will never remove all organic matter when you bail. Figure 1 shows how much straw can be removed to maintain the SOM using reduced tillage and moldboard plow.

Figure 1. Amount of straw that can be removed
without loss of soil organic matter (Johnson et al. 2006).
While it is critical to maximize profitability from the land, you need to balance short-term economics with long-term sustainability. When harvesting wheat residue, use common sense and consider these guidelines to maintain soil organic matter levels and protect against erosion:
  • Rotate straw harvest among fields so that residue is not removed from the same field every year.
  • Reduce tillage following straw harvest.
  • Use manure instead or in addition to commercial fertilizer to add carbon back to the soil.
  • Consider winter cover crops. Roots from winter cover crops are extremely effective at scavenging residual soil nitrate and adding carbon to the soil.

Additional Resources

  1. NRCS nutrient removal calculator
  2. Central Minnesota Hay Auction

Print Friendly and PDF