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

Final report for FNC21-1283

Project Type: Farmer/Rancher
Funds awarded in 2021: $9,000.00
Projected End Date: 01/31/2023
Grant Recipient: Knutson Shorthorns
Region: North Central
State: Minnesota
Project Coordinator:
Zachary Knutson
Knutson Shorthorns
Expand All

Project Information

Description of operation:

Our operation is a 4th generation family farm with ~20 beef cow/calf pairs, 10 yearling heifers, and 10 breeding ewes at the time of this research. The land base was 27 acres of pasture with 100 acres tillable at the start of the research. We have been rotationally grazing perennial pastures since 2018 gradually increasing rotation frequency until we adopted daily moves in 2020. We now balance daily and every-other-day moves for a mixture of work-life balance and grazing efficiency. The field used in this research was in conventional corn/soybean rotation (minimum tillage/no-till, respectively) for many decades leading up to the research.

Summary:

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. 

Project Objectives:
  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

Research

Materials and methods:

We used a no-till drill for planting because the terrain is mostly 12-18% slopes (per NRCS) and we wanted to minimize soil disturbance. We planted the triticale and winter cereal rye in October 2020 following soybeans because it was too late to plant anything else in our climate. The summer mix we used was a pre-mix of Buckwheat (20%), cow peas (20%), Proso Millet (15%), sorghum/sudangrass (10%), Sunn Hemp (10%), and Sunflowers (5%) The fall mix was a combination of a premix (80% winter cereal rye, 15% hairy vetch, 5% daikon radish) and oats for increased fall grazing tonnage. 

In total, the field was approximately 42 acres. The perimeter was fenced on 3 sides with 5 strands of high-tensile wire. One side runs along the driveway and has not been fenced to maintain easy field access. This open side and all interior fencing was done with electrified Kiwitech poly wire. The livestock were already familiar with the poly wire because we used it during summer and fall 2020 for rotational grazing, so 2 strands was sufficient for both cattle and sheep (1 strand when sheep were elsewhere). 

To water the sheep/cattle, we used a 50 gallon poly tank with a Jobe water valve. We ran garden hoses with Y-valves every 125' around the perimeter of the field. The hoses were cheaper than HDPE, however we're losing ~25% of them annually to rodents and heat swelling which makes HDPE the better long-term investment.

Research results and discussion:

Carrying capacity varied significantly, ranging from 3.1 to 35.1 animal units per acre per day. The most extreme variation was observed while grazing the winter biennials (30# triticale + 30# winter cereal rye mix). On April 16, carrying capacity was approximately 3.47 Animal Units/Acre/Day. This increased to 13.5-16.5 from April 22 through May 7. From May 8 through June 1 the carrying capacity ranged from 22.9 to 28.9 AU/Ac/D, dropping off significantly to 12.7 and then 3.1 AU/Ac/D on June 4th and June 6th. This was due to the air temperature exceeding 90 degrees Fahrenheit the last week of May. This abnormal heat wave (our soil temps were still below 55F at the time) caused the small grains to rapidly mature and the livestock became uninterested in grazing the mature cereal rye/triticale.

The summer annuals (20% each: buckwheat, cowpeas, soybeans; 15% Proso Millet; 10% each: sorghum/sudangrass, Sunn Hemp; 5% sunflowers; total 47.6#/Ac) struggled to get established due to the drought conditions. We tried to time the planting with rain, but the seeds waited over 2 weeks for their first rainfall. After waiting 32 days, and receiving under an inch of rainfall, the carrying capacity was approximately 28 AU/AC/Day on the summer annual mix. The plants only received another 2 inches of rain over the span of the first rotation, so stocking density held steady between 28-35 AU/AC/Day. Due to the lack of rain and soil moisture, we had to wait until October for the 2nd grazing pass (discussed in next section).

The fall mix (residual summer annuals; 40#/AC winter rye; 7.5#/AC hairy vetch; 2.5#/AC Tillage Radish; 30#/AC oats) performed well in areas where the sorghum/sudangrass was grazed harder. Tillage radishes seemed to grow everywhere, but produced the most above-ground biomass in open areas (including spots that were higher-traffic earlier in the grazing season). Grazing of the fall mix started in October, but was interrupted by subsequent frosts that made the sorghum/sudangrass potentially dangerous and required removal for a period. The oats/radishes appeared to maintain their quality into the first week of December through several freezes, and didn't show negative impacts until after a day that dropped to single digits (Fahrenheit) around Thanksgiving. However, during the subsequent 2 weeks, the cattle still favored the radishes over everything else and they maintained textbook-perfect manure consistency from the dead sorghum/sudangrass and underlying green forages. Carrying Capacity for the (2nd round summer annuals/fall mixture) grazing cycle ranged from 26-35 AU/AC/Day up until the frost event, then falling to 22.9 and 19.4 AU/AC/Day from the 1st of December to the final grazing day, December 10th.

See the Project Summary for the full Economic Analysis

General Observations of Specific Forages: 

Due to the drought, it took approximately 6 weeks for the sorghum-sudangrass to reach the recommended 18-24" start-grazing height. Certain spots (where hay bales were fed in the spring to increase rest periods) had exceptional growth in excess of 4 feet at 9 weeks, however the surrounding areas only reached approximately 3 feet before going to seed. Sunnhemp performed best later in the season when the drought subsided. Sunflowers bloomed throughout the season at a range of heights (from 4" to 3' tall) indicating a benefit to pollinators even when conditions were not suitable to developing significant forage for livestock. Small grain biennials that got ahead of us laid down a strong seedbed that contributed a significant amount of plants for the fall grazing. These plants have stayed green through the grazing events and will likely provide an increased benefit of living roots and "armor" through winter with a density that could not be achieved with a drill/planter. The tillage (daikon) radishes were a definite favorite amongst the cattle, who would seek them out first when entering a new paddock. Cattle were consistently seen chewing on the tubers, thus spreading out the nutrient-scavenging benefit of each plant.

Participation Summary
1 Farmer participating in research

Educational & Outreach Activities

3 Curricula, factsheets or educational tools
1 On-farm demonstrations
1 Tours
1 Workshop field days

Participation Summary:

24 Farmers
1 Ag professionals participated
Education/outreach description:

We had a field day with ~2 dozen graziers in attendance. We conducted a species-identification exercise with the summer annuals and walked amongst the field at ~9 weeks post-planting to evaluate species performance. The largest benefit of the field day was the numerous thought-provoking questions, and side conversations, discussing ways to improve the implementation of a project like this. In addition, several posts were made in the Regenerative Grazing and Cover Crops groups with positive feedback. Posts reached thousands of people, for example: four separate posts each reached 5,026, 5,803, 6,355, and 13,089 people as of the date of this report. Posts can be found on the Knutson Shorthorns Facebook page, and they will remain there for reference indefinitely.

Facebook Post Compilation 

This PDF compilation includes each post written and published about the SARE project on the Knutson Shorthorns Facebook Page. Posts included photos, which were not included for data file size purposes but can be seen on the Facebook Page.

Learning Outcomes

2 Farmers reported changes in knowledge, attitudes, skills and/or awareness as a result of their participation
Lessons Learned:

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

By incorporating the lessons learned above, forage yields/carrying capacity could have been much higher and generated a better cash-flow, even under identical growing conditions. In a more average year, the summer annuals would have yielded significantly more forage, and the return could've been adequate to cover rent. Overall, I think this system is much more applicable as an extension of an existing grazing enterprise, or as an opportunity to sublease a field to a grazier for a season as part of a crop rotation. Attempting to manage stocking rates solely on this field without another pasture to offset the volatility in yields from week to week would expose a stocker enterprise to significant marketing risk, or increase costs of buying hay to mitigate the variations--thus eliminating economic feasibility altogether.

Project Outcomes

1 Farmers changed or adopted a practice
1 New working collaboration
Recommendations:

Further research tracking changes in soil nutrients following grazed cover crops would be beneficial and provide valuable insights into the potential economic value this adds to the forage value analyzed in this study.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.