What is Your Corn Fodder Worth?

 

There are three main strategies to manage fodder (also called stover or residue) after corn grain harvest: keep it in the field; bale it; or graze it. This article explores the advantages and disadvantages of each strategy and the impacts to farmers’ bottom line.

 

 

One of the benefits of keeping corn fodder in the field is soil conservation. The NRCS recommends keeping soils covered as much as possible for improved soil health. High levels of soil cover and roughness reduce soil loss according to RUSLE2, a tool used by NRCS to estimate erosion potential. Corn fodder left on the soil surface after grain harvest can easily provide 90-95% cover; additionally, the remaining standing cornstalks increase field roughness. Conversely, removing fodder through baling or grazing can reduce cover by 25 to 80% depending on the method used (chopping, raking, and baling vs. baling combine wind rows only vs. strip grazing, etc.), leaving the soil more vulnerable to erosion, especially on sloping ground.

 

We know that soil conservation does not just help the environment—it also makes financial sense. Iowa State University Extension summarized in a 2012 factsheet that soil erosion can cost farmers more than $20 per acre (adjusted for inflation) per year. This estimate accounts for a number of factors, including nutrients in the soil that are unavailable to the next crop, resulting in increased fertilizer costs; reduced crop yield when topsoil moves and poorer soil remains as substrate for crop growth; loss of land value; potential damage to property and roads; and water body impairment from moving soil.

 

Beyond keeping soil and soil-bound nutrients in place via erosion protection, maintaining corn fodder in the field allows nutrients tied up in leaves, stalks, and cobs to become available to subsequent crops as the residue breaks down. It is important to consider the value of these nutrients, and their cost of replacement, when deciding how to manage fodder. Corn fodder dry matter yield is approximately the same as corn grain yield—so, for 150 bu/A corn, we estimate approximately 3.5 tons of dry fodder (150 bu/A x 56 lb/bu x 84.5% DM / 2,000 lbs/Ton).

 

Table 1 shows the approximate nutrient content of corn fodder per dry ton (based on calculations by Michigan State University Extension). Current national average prices are listed in the table—these are for demonstration purposes only. You should use your own local prices for your calculations, as fertilizer prices vary widely depending on the time of year, location, and volume purchased.

 

 

Using the values from Table 1, the value of nutrients contained in the fodder is $21.76 per ton.

 

Considering corn fodder as a nutrient and conservation resource reveals the value of keeping it in the field. However, doing so may be a missed opportunity for an economical feed or bedding source. Additionally, corn fodder can harbor pathogens that may harm the next crop, and slow soil drying and warming in the spring.

 

 

Removing fodder from the field, through baling or grazing, can be an economical way to feed cattle and extend the grazing season.

 

When deciding if grazing corn fodder is right for an operation; first consider its nutritive value (Table 2 and Table 3). The nutrient content of the fodder depends on which part of the corn plant cattle selectively graze or what fodder is mechanically collected during baling.

 

Table 2. Nutritional Content of Corn Crop Fodder

 

In Vitro Dry Matter Digestibility (IVDMD) is approximately equal to total digestible nutrients (TDN). Adapted from: University of Nebraska – Lincoln, Extension (document EC278)

 

Table 3. Average Composition of Corn Stover

 

 

Mechanical harvest of corn fodder can provide winter feedstuffs in the form of baled corn stover. Nutrient availability in corn stover varies and can depend on the harvesting process. The mechanical harvesting process generally captures more of the stalk and cob than grazing, which are less palatable and less nutritious. There have been improvements in technology that make it easier to harvest more husk, leaves, and cob; read more about selective mechanical harvesting from the University of Nebraska-Lincoln.

 

 

Grazing corn fodder left in the field after harvest is one way to extend the grazing season and lower feed costs. For every bushel of corn taken from the field, there are approximately 18 lbs. of stem, 16 lbs. of husk and leaves, and 5.8 to 6.0 lbs. of cobs left as fodder (all on a dry matter [DM] basis).

 

If given free access to an entire field of fodder, cattle will first select any grain remaining, followed by the husk and leaf, then cob and stalk. Adaptive grazing techniques (like using strip grazing) can optimize the amount of fresh fodder available and structure what the cattle are able to selectively graze. This can create a more uniform diet. Because cattle will selectively graze on remaining grain first; it is important to scout the field for excess grain piles that can cause grain overload and related animal health issues. Fields with more than 8 to 10 bushels on the ground should be managed in a way that moderates grain intake. Adapting cattle to grain supplementation before turnout is another way to minimize digestive upset.

 

It is important to recognize that the quality of the fodder will change as the season progresses. The rate of quality decline is depending on stocking rate and environmental factors like moisture, precipitation, and field condition. It can be advantageous to graze during the first months after harvest (October, November, December) instead of using the field in late winter (January, February). Nutrient composition of the fodder at the start of the grazing period is approximately 6-7% crude protein and 65-70% TDN compared to lower levels (5% crude protein and 40% TDN) at the end of the grazing period.

 

Availability of fodder for cattle can be dictated by snow depth and especially ice cover, plan to have alternative sources of forage available to prepare for weather-related limitations.

 

 

According to research from Iowa State University, corn fodder can replace approximately 25 lbs. of hay equivalent per day for a medium-sized cow (not nursing) or 0.375 tons per month. Depending on the class of cattle consuming corn fodder, additional supplementation may be required. Salt, mineral, and Vitamin A supplements are recommended for cattle grazing crop fodder. To read more about supplementation for different classes of cattle and develop stocking rates, see Grazing Corn Stalks with Beef Cattle .

 

The overall cost of grazing corn fodder will depend greatly on rental rates (if needed), and associated costs of fencing, water, and transportation. Iowa State University has an electronic spreadsheet to assist producers with estimating a price for grazing fodder. To access the spreadsheet, to download the tool scroll to the bottom and select Decision Tool A1-70 Corn Stover Pricer.

 

 

From the approximate 56 lbs of fodder left in the field per bushel of corn, cattle will remove close to 25% during feeding activities, with other losses related to animal movement and weather. Research on nutrient removal from the University of Nebraska – Lincoln found that a pregnant cow grazing at suggested stocking rates for 90 days on a 230 bu/ac cornfield will remove approximately half a ton of fodder, and 2 lbs of nitrogen (N) per acre. Potassium removal is negligible. The amount of phosphorus (P) and calcium (Ca) available in fodder is generally less than sufficient to meet nutritional needs. As a result, producers providing a free-choice mineral containing both would result in an addition of these nutrients through manure deposition. There were no significant changes in the status of nitrogen (N), phosphorus (P), potassium (K), and organic matter (OM) in studied fields that were grazed compared to un-grazed.

 

Additional studies, coming from the University of Nebraska-Lincoln, showed no detrimental impact on soil properties like bulk density and penetration resistance (a measure of compaction). Continuous grazing of fodder did not change corn yields in rotation, and slightly improved soybean yields by 3.4 bu/ac. In wet conditions, researchers noted rough soil surfaces that dried unevenly. This has the potential to impact seed set and yields due to difficulty planting. Removing animals during spring months, when soils are saturated and no longer frozen can prevent impacts to our seedbed.

 

During dry years, the potential for increased nitrate concentrations are a risk when grazing (or baling) corn fodder. Corn fodder should always be tested for nitrates to guide decision making. Generally, the more palatable grain, husk, leaves, and cob will be consumed first. The lower portion of the stalk (ie. that 6 to 8 in. closest to the ground) is typically highest in nitrates. If nitrates are a concern, cattle can be supplemented with hay or grazed to minimize stalk consumption to reduce the risk of nitrate poisoning.

 

 

You may choose not to graze fodder for any number of reasons; perhaps fields lack fencing or water infrastructure, there are no livestock on or in proximity to the farm, or you have an established market for harvested forages or bedding. Baling corn stover is another option worth considering.

 

 

The preceding section demonstrates that stover can provide economic forage for cattle. But how much do you get, and is it worth it? Let's again assume a 150 bu/A corn yield and 3.7 dry Ton/A stover. Depending on whether the stover is baled from combine windrows; raked and baled; or chopped, raked and baled, an expected 50%, 65%, or 80% of the stover will be harvested, or approximately 1.8, 2.4, or 3, 1,200-pound bales per acre, respectively.

 

This could replace part of the medium-quality hay in a feed ration when supplemented with additional protein. For example, following this Iowa State University Extension calculation, corn stover can replace about 1.16 tons of grass-legume mix hay, with an additional 0.22 tons of whole soybeans needed to bring up protein levels (this is a 1:1 replacement for DDGs [dried distillers grains]). Using the current mixed-hay price of $198 per ton, and soybeans currently at $316 per ton, the value of the feed replaced per ton of stalks is approximately $160. At 0.6 tons per bale, that’s $96 of feed replaced per bale.

 

Before logging a net gain from selling bales or saving money on your feed ration, remember account for the cost of baling and transporting stover in addition to the fertilizer replacement cost mentioned in Table 1. Baling and transportation cost can vary widely depending on if custom operators are hired, or personal machinery and labor costs included. Iowa State University has another factsheet that can help and drill down specifically on the economics of harvesting and transporting corn stover, whether custom hire or on-farm machinery and labor are used. As always, use current local values for accurate estimates. Most recent custom rates are linked for Pennsylvania, Maryland, and Ohio.

 

For example, custom hire for stalk chopping, raking, and baling, and transporting bales 25 miles to end location using approximate current local prices adds up to $27 per bale. Accounting for nutrient replacement per 0.6 ton bale brings the total to produce one bale to approximately $40.

 

The total cost to the producer per bale is the minimum amount farmer should be willing to accept, while the feed value is maximum the livestock producer would be willing to pay—the actual price paid should be negotiated somewhere within this range. A realistic range would be from $40 to $96 per 1,200-pound bale for the scenario given above. It is important to consider current local pricing as well as reports from local hay auctions. Remember the above values include custom work and hauling, which increase the cost of production significantly. Baling stover with your own equipment and keeping it on-farm will drastically reduce the cost of production per bale.

 

 

Initial moisture of stover at harvest and storage conditions can influence dry matter retention and nutritional composition. Plan for losses of material related to storage and feeding. If stover bales are fed free-choice anticipate feed refusal of less palatable components. Bale feeders can be moved to allow cattle to access and utilize refused feed as bedding.

 

If you choose to bale stover, the University of Minnesota Extension recommends not removing fodder from the same fields every year; using manure to replace organic matter; reducing tillage; and planting cover crops as best practices.

 

 

Keeping fodder in the field is best when:

Grazing fodder is best when:

Baling stover is best when:

The choice to leave fodder in the field, bale, or graze after corn grain harvest should be based on each farm’s individual needs and goals. The value to the buyer, cost to the seller, and local forage market should all be considered. If you are unsure, reach out to your local Extension Educator for a second opinion. Always take the time to critically weigh the costs and benefits of different management strategies to make the most informed decision for your farm.