Evaluating the forage potential and financial viability of grazing diverse annual forage crops in a tradition corn/soybean rotation

View the project final report

Commodities

• Animals: bovine, sheep

Practices

• Animal Production: feed/forage, feed management, free-range, grazing management, grazing - multispecies, grazing - rotational, stocking rate
• Crop Production: cover crops, cropping systems, crop rotation
• Production Systems: holistic management, integrated crop and livestock systems

In our area, most fields are exclusively corn/soybean rotations with very few hay fields. We want to explore the potential of adding a diverse annual forage crop mix as a third crop rotation. An annual forage crop would be more fluid in the rotation than a 3-5 year alfalfa field, and would provide new grazing opportunities in a traditional corn/soybean rotation.

We rotationally grazed cattle and sheep across a mixture of biennial small grain forages, summer annual and fall cool-season cocktail mixes. We wanted to explore improved farm profitability by allowing expansion, or by allowing existing pastures to stockpile for winter grazing--thus reducing hay inputs. Also, by grazing the forages, equipment is not needed for making hay. Livestock were also perfectly content grazing at times when machinery couldn't make hay--reducing the stress of timing the harvest and improving quality of life.

While many producers want to incorporate grazing cover crops into their operations, most are deterred by the task of hauling water and attempting to keep it "open" through winter. By grazing summer annuals and stockpiling existing pastures, winter grazing can be done near heated fountains that are already established--thus improving farmer quality of life and profitability simultaneously. 

Research Methodology

Paddock sizes were estimated to target ~2 days of grazing per paddock based on the previous paddock's carrying capacity. We used the NRCS Web Soil Survey tool to approximate acreage. 

What we learned from the biennials: Initially we followed local cover crop planting recommendations for the winter cereal rye/triticale, however if the plan is to graze rather than simply cover the ground, one should plant at least 100#/acre. Grazing the biennials in larger paddocks would help move the animals faster and keep ahead of the rapid early maturity. It is better to clip each plant lightly and return than to try to graze down the plant to 2-3" and risk a heatwave sending the rest of the field to seed.

What we learned from the summer annuals: You CAN drive a JD no-till drill through 2-3' tall sorghum/sudangrass and get solid seed contact without plugging. The winter cereal rye used up significant soil moisture by going to seed, and may not be the best small grain biennial for a project like this in a drought year. Also, the generic sorghum/sudangrass tillered significantly AFTER being grazed. Knowing this, I would've used larger paddocks and let the cows cover more ground faster once the plants reached the 18-24" height in order to get every plant's tillering ability triggered, thus increasing yields through the rest of the year. Instead, we used the 'slow growth, slow moves' philosophy and likely sacrificed some yield potential.

What we learned from the fall grazing: Even though the sorghum/sudangrass turned brown after freezing, it still had sufficient nutrition for 2nd trimester dry beef cows and dry ewes; we could easily increase the rate of tillage radish seeding to get more soil health benefits and preferred biomass for the cattle; having the biennial small grains go to seed can produce sufficient seedbank to not need to buy more biennial small grains for fall seeding

Economic Analysis

Biennials: ~16,078lbs dry matter in 1st rotation, ~20,046lbs dry matter in 2nd; ~860lbs dry matter per acre worth ~$78.69/acre at $140/ton hay (15% moisture, 10% storage/handling loss)

Summer Annuals: ~34,398lbs dry matter in 1st rotation; ~819lbs dry matter per acre worth ~$74.94/acre at $140/ton hay (15% moisture, 10% storage/handling loss)

Fall grazing: ~20,491lbs dry matter; ~488lbs dry matter per acre worth ~$44.65/acre at $140/ton hay (15% moisture, 10% storage/handling loss)

Planting Costs: $20/acre*3 passes=$60/acre

Seed Costs: Biennials: $35.50/acre; Summer Annuals: $40.47/acre; Fall Mix: $40.77

Forage value less seed and planting costs: $21.54/acre, excluding rent and labor

Of note, grazing the summer annuals did help us achieve the goal of stockpiling existing perennial pastures for winter grazing. We have ~20 acres of cool-season improved pastures that have not yet been grazed as of December 11th, so we will be able to save more hay than the direct savings listed above. There are other ways to acquire this perennial pasture (such as destocking the herd), so assigning an economic value to this is difficult, but it is worth considering. 

In addition, several species in these forage mixes are known for "nutrient scavenging" and likely will contribute additional N, P, K, and S nutrients for the subsequent crops. Given the cost of fertilizers in 2021, this is great timing and absolutely carries some value. However, further research is needed to determine the amount of nutrients in a diverse mixture such as these.

Conclusions:

Overall, the forages are not likely to compete with corn or soybean row crops in a purely cash-flow analysis. However, given the hay savings outweighed the Variable Costs (excluding labor), there is potential for this 3rd crop rotation. It is important to recognize this year was a drought with the region entering D1 (moderate drought) in May, and D2 (Severe drought) in August. This impacted the forage yields significantly, and would have certainly impacted corn/soybean yields on the same land. While we will never know for sure what the yields would have been, these particular fields only produce ~180 bushel corn or 40 bushel beans in a normal year, so there's no guarantee these crops would have generated more profit (or less loss) than the forages in the severe drought.  Further, by incorporating the lessons learned above, forage yields/carrying capacity could have been much higher and generated a better cash-flow in identical growing conditions.

Farmer Actions from the Education Program:

One individual at the field day was in the planning stages of starting a grazing enterprise, and during conversations with him it sounds like he will potentially adopt some cover crop grazing in the transition between purchasing row crop ground and converting it to perennial pastures. 

1. Explore forage potential of diverse annual forages planted throughout the growing season
2. Estimate the economic feasibility of adding diverse summer forages to a corn/soybean rotation in order to expand grazing opportunities and reduce the need for harvested forages
3. Share findings with other graziers through the Land Stewardship Program, social media websites, and via regenerative grazing group discussion