Daily Rotational Grazing, Changing Soil Health on 12 acres
Our sixteenth Profiles of Soil Health Heroes is Mike McElroy. Mike is the District Conservationist with the Natural Resources Conservation Service (NRCS) in Greeneville, Tennessee. Mike bought his current place in 1991. The original 4.7 acres of pasture had 5-strand barb wire fence. The farm needed quite a bit of cleaning up to prepare it for grazing. Mike began grazing in the early 1990s. He read about rotational grazing but did not understand it well enough to practice it. He bought some calves and began rotating calves once a week in 1996. Richard Spain a local farmer found out about grazing clubs from his brother in Missouri. In 1996, Richard Spain influenced Mike and a few others to start the Four Seasons Grazing Club in Greeneville, Tennessee (grazing club continues to meet 4-6 times per year). Greg Brann, State Grazing Specialist with NRCS also provided a lot of guidance to Mike.
Mike took his 4.7 acres and began moving calves from field to field once a week. He said, "I had no idea what I was doing." Still early in Mike's experiences into a rotational grazing, he began to research tools needed to practice rotational grazing. He said, "I will not recommend anything until I have proven it myself." He tried components of grazing management such as fencing, energizers, step-in posts, spring gates, and high tensile wires. He also has an abundance of poly wire with different types of reels. Mike weeds out what does not work.
Mike has a low input philosophy. He believes if one will manage grazing on the current grass and build up the fertility the diversity of species will take care of themselves. His current forages consist of Kentucky-31 tall fescue, orchardgrass, crabgrass, bermudagrass, dallisgrass, Johnsongrass, Kentucky bluegrass, bromegrass, white clover, red clover. Mike only seeds 2 pounds white clover and 4 pounds red clover every three years. He broadcasts his clover in February.
Early in 2000, he bought additional 1.5 acres. He installed 4-strand high tensile electric fence. In 2013, he built a 3-stand high tensile electric fence through woods on the property line and used white vinyl tee post. He uses step-in posts for his multiple temporary paddocks. In 2010, Mike acquired more fields by leasing. He currently grazes 12 acres. Mike has evolved from steel posts to vinyl T-posts. He testified that recently he had some bad weather, and trees fell on his fence in the woods. He made repairs in less than half an hour. If it had been 5-strand barb wire, it would have taken half day to a day for repair. Mike preaches to others what works on his farm.
Mike talks with a gleam in his eye on how he evolved to his current system of contract grazing for dairy heifers. In 2000, he took fecal samples in one year from April through October. His lowest crude protein was 11.4% crude protein, and his highest tested crude protein was 17.4%. The total digestive nutrients ranged from lowest, 66.8% to the highest, 74.4%. Mike transitioned to moving the calves daily in 2001. He also began a trial contract with a local dairyman. The dairyman asked Mike to prepare the dairy heifers the traditional way by feeding them grain. Mike shared with him the results of his 2000 test of crude protein and total digestive nutrients. With some skepticism, the dairyman agreed to let Mike pasture the dairy heifer calves from April to December. The agreement was a trial run. Mike would return the calves in December, and the dairyman would decide if the agreement would continue.
Beginning in 2001, Mike started taking full-weight class dairy heifers (Holstein breed) between 400-425 pounds. He began daily rotation of the 10 calves. He normally receives them last week of March to around the first day of April. He utilized intensive grazing for short duration, one day. By the middle of December, Mike delivered that first group of calves at about 800 pounds each. The dairyman remarked as Mike backed up the trailer, "those calves are bigger and healthier looking than his other calves." He also stated to Mike; "would you be interested in doing again next year." Mike is going into his 16th year with this agreement. Mike's management is improving the soil health which I will illustrate later. His management first and foremost improves grass growth and then animal health. The healthy grass affects the soil which continues to produce healthy grass.
As Mike has continued to contract with this same dairyman. The dairyman has said "every heifer that returns from Mike's farm has always bred." When you are in the milk business, breeding heifers are an essential. Mike asked himself, why is this the case? He has thought of the following factors:
- Good genetics
- Good environment
- Grazing management - good nutrition from forages
- Social movement of the animals, daily rotation
- City water, clean water
- Spray for flies as needed, three times a year
- Abundant free choice of minerals
So Mike is going on his 16th season with intensive rotational grazing for short duration and long rest periods (up to 46 days). His soil and forages have steadily improve over this time period. Mike keeps detailed records. His bottom line depends on daily gain that ultimately doubles the weight of the dairy heifers in 8 months. His records shows average daily gains since 2001.
Average Daily Gain
Mike has seven fields that he normally uses poly tape to create 0.25 acre paddocks, intensively grazes starting heights that will vary from eight inches to 24 inches and grazes down to 4 inches. Mike is following basic biological principles. Intercepts solar energy with green plants through photosynthesis. The plant produces carbohydrates. As the plant sloughs off roots and forage is left as cover after short rotations, soil microbes and macro life feed off roots and forage remains. Carbon from plants are slowly but surely converted to soil carbon or soil organic matter. Mike is following principles to build soil organic matter and thus, soil health: 1. minimize disturbances; 2. keep the soil covered; 3. keep roots growing nearly 365 days; and 4. promote diversity. The short duration, high intensity grazing follow those four principles.
Mike began soil testing in 2001. Results are shown for 201, 2005, and 2016 below in Tables 2-4. Fields 4 and 5 were not obtained until 2005, so no comparisons in 2001.
Table 2 (2001).
|Field||pH||Phosphorus (P)||Potassium (K)||Soil Organic Matter (SOM)|
|1||5.7||14 lbs/ac Low||244 lbs/ac Medium||1.2%|
|2||6.8||20 lbs/ac Low||152 lbs/ac Low||1.3%|
|3||6.2||50 lbs/ac Low||128 lbs/ac Low||1.7%|
Table 3 (2005).
|1||6.0||16 lbs/ac Low||200 lbs/ac Medium||1.9%|
|2||6.1||56 lbs/ac Low||296 lbs/ac Optimum||2.2%|
|3||6.6||32 lbs/ac Medium||222 lbs/ac Medium||1.8%|
|4||6.3||62 lbs/ac Optimum||178 lbs/ac Low||2.3%|
|5||6.4||34 lbs/ac Medium||64 lbs/ac Very Low||1.9%|
Table 4 (2016).
|1||6.5||48 lbs/ac Medium||248 lbs lbs/ac Medium||4.1%|
|2||6.6||62 lbs/ac Optimum||256 lbs/ac Medium||4.0%|
|3||6.0||110 lbs/ac Very High||296 lbs/ac Optimum||5.6%|
|4||6.2||92 lbs/ac Optimum||298 lbs/ac Optimum||4.4%|
|5||6.6||66 lbs/ac Optimum||176 lbs/ac/low||4.4%|
Results of the soil tests show steady increases in P and K. The pH levels have significantly improved to mid 6s with the exception of field 3, 6.0. Mike has applied lime once in 25 years, 1997. Soil organic matter which is the best indicator of soil health has climbed to impressive numbers ranging from 4.1 - 5.6%. This increases in SOM by almost 2% is improving the field’s ability to provide nitrogen (N). Mike has not fertilized since 2008. His production has increased as shown in Table 1, average daily gain. Soil structure is granular and sub-angular blocky which translates into good pore space resulting in better infiltration and root growth. Earthworms are plentiful with every digging. Soil has a strong earthy smell indicating healthy soil biology. Soil is easily penetrated with shovel, again showing good structure without any stratified layers. Mike easily grazes 10 animals on 12 acres without the need of any hay.
Mike's intense grazing over short duration has paid off economically by consistent increases in average daily gains, Table 1. Mike also has not applied any fertilizer since 2008. This is a total savings of $600 or nearly $100.00 per acre. In 2015, he bought 5 bales at 700 pounds per bale due to a drought and an estimated 10 days grazing remaining. He ended up not using them, so he sold them. Prior to using his current system since 2001, Mike would use two 700 pounds of bales. His savings now are $40.00/bale or $80.00/year. Mike use to clip multiple times per year, but now he lets the calves harvest 100 percent of forages. He no longer clips, and sees no agronomic advantages in clipping his pastures.
In 2015, Mike’s grass became very tall by June due to precipitation. Mike was rotating 0.25 acre per day. Mike is planning to increase the size of paddocks to 0.5 to 0.6 acre this grazing season, 2016 and try to cover the entire 12 acres in 20-24 days to keep the grass somewhat lower height. He will adjust based on precipitation and may do this a total of three times. He will then go back to his 0.25 acre after 60-72 days grazing. This should keep the grass at vegetative stage during spring growth.
As I visited Mike's farm on Monday March 21, we noticed his grass is at about 6 inches in height nearly tall enough to begin grazing. Mike received his calves on March 28, 2016 and began training his calves by putting small portions of feed in the paddocks. The calves train quickly.
On my visit, we dug many holes and saw dark colors, with excellent earthy aroma, good crumbly structure. The soil as well as the bottom line has changed for Mike. Intensive grazing for short duration, daily movement of the heard has resulted in the results shown previously. Farmers can improve soil health by following the four principles: reduced disturbances, keep the soil covered, keep roots growing, and add diversity. Mike is changing the landscape at 12 acres at a time.