Establishment of Miscanthus (Miscanthus x giganteus) as an Alternate Bedding Supply

Final Report for FNE11-719

Project Type: Farmer
Funds awarded in 2011: $7,350.00
Projected End Date: 12/31/2014
Grant Recipient: Central Manor Dairy
Region: Northeast
State: Pennsylvania
Project Leader:
Steven Harnish
Central Manor Dairy
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Project Information

Summary:

Our goal in this 3 year project was to analyze the feasability of using chopped Miscanthus x giganteus as dairy cow bedding. In the 2011 growing season we successfully established a stand of miscanthus on a 2 acre plot. We selected a plot that surrounded the wellhead of a nearby elementary school. Growing miscanthus instead of a corn/soybean/alfalfa rotation allows us to maintain soil fertility in the well setback without manure application. After a very dry early summer in 2011 we still had 75% of our plants growing in the fall. The plot experienced excellent growth in 2012 yeilding 5.25 tons/acre at 15% moisture.  We ran a bedding trial with the product from that harvest finding that the miscanthus compared favorably with kiln dried wood shavings in our compost bedded pack barn.  Yields increased during the 2013 growing season with a harvest 6.5 tons/acre at 13% moisture.

 

Introduction:

Kiln-dried shavings have been the bedding material of choice for dairy producers in the Northeast. On dairies that are not equipped to handle sand bedding, shavings support less bacterial growth than other bedding alternatives. The shavings are a byproduct of woodworking operations and require significant hauling expense to reach most farms. In recent years the emergence of wood pellets as a heating source has increased the price and reduced the availability of wood shavings, especially in winter months. I propose that locally-grown Miscanthus canes could replace much of the sawdust and shavings currently trucked to dairy farms. 

Miscanthus is a high-yeilding perennial grass that produces tall canes through the spring and summer. The plants lose their leaves in the fall and dry out over the winter. The dried canes can be harvested using either a forage harvester or baler. Once established, a stand of Miscanthus x giganteus needs no tillage, no replanting, no fertilizer and no herbicides or pesticides. Some European fields have been harvested for decades with no management needed between harvests. Most trials in the US report a 10-15 ton/acre yield after the stand reaches maturity. (Some commercial marketers claim much higher yields.) Miscanthus x giganteus is a sterile hybrid, so there are no viable seeds produced and no opportunity for it to be invasive. The major drawback of Miscanthus as a bedding source is the cost of establishment. Additionally, a new stand produces little or no yield in the first year and will not reach maximum yield until the third year. The typical method of propagation is to plant rhizomes cut from either potted plants or 1-2 year-old stands. The rhizome dividing and planting is either very labor intensive or requires very expensive, specialized equipment. The interest in Miscanthus as a biomass crop has led to the availability of this equipment in the United States. A recent development that would lower the cost of establishment for a medium-scale project like this is the marketing of a plug produced from rooted stem cuttings. 

At Central Manor Dairy we selected a plot of land surrounding a well that supplies drinking water to an elementary school adjacent to the farm. The nutrient management plan for our farm prohibits manure application within 100 feet of a wellhead. Selecting miscanthus for this field allowed us to avoid any fertilizer application near the well.

Project Objectives:

Our goal was to produce enough dried, chopped miscanthus stems to do a bedding comparison trial after the second growing season.  The bedding trial took place in our compost bedded pack barn and compared miscanthus with kiln dried shavings. The goal is for the chopped miscanthus to absorb cow manure and urine and then dry out after aeration.  Common bedding materials like corn fodder and straw are unsuitable in compost barn because they retain the moisture and don't dry out again.

The two types of bedding were applied weekly with a manure spreader to two halves of the bedded pack barn.  From February 17 to March 19, 2013 the pack was aerated three times per day.  On the 19th I blended samples from eight locations on each half and took temperatures at 8 locations in each.  The miscanthus averaged 37% moisture and 129°F.  The wood shavings averaged 42.5% moisture and 120°F.  By both measures the miscanthus proved to be an excellent replacement for wood shavings.

Cooperators

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  • Dan MacFarland

Research

Materials and methods:

The establishment phase of the project is by far the most expensive and labor intensive part of this project. We selected plug plants instead of rhyzomes in order to use a 3-row mechanical transplanter. This was supposed to automate much of the work and enable us to plant the field in 2-3 hours. We communicated to our supplier the need for small plants that would fit through the transplanter and were assured that we would get the youngest plants available. When the plants arrived it was obvious that they were too large. Some plugs had leaves up to 14 inches long. We purchased an old, single row manual transplanter from a relative instead. 

In 2011, After a week of wet weather, we were finally able to plant on May 27-28. It took about 14 hours to plant the 2 acre field with the old planter. We didn't have the ability to add water during planting, but the ground had received 3 inches of rain from May 16-20. The only significant rainfall we had in the next 6 weeks was an inch on June 10 and less than an inch on july 8th. The miscanthus that had long leaves was wilting and the plugs that did not have leaves were not emerging. Plugs that were only half buried by the transplanter dried out and died. Finally steady, frequent rain begain on July 25th and continued through the month of August. Plants with wilted leaves that had shown no growth since May started growing rapidly. All of the submerged plugs put up multiple shoots. It appeared that the plugs survived the dry spell if they were completely buried during planting. By September each plug had formed a clump of dozens of leaves. The larger plants grew thick stems, which dried out into the canes that stay standing over the winter.

We used a single-row tractor mounted cultivator for weed control in mid-June and then 1 application of pendimethalin (Prowl) herbicide in July. Our agronomy consultant suggested that cultivation might not have been necessary if we had applied Prowl before planting. 

For the second growing season, in 2012, the only work our miscanthus plot needed was weed control. We applied Prowl in April to prevent weed emergence in the spring and summer. The results were excellent, no further applications were necessary. From May to October the miscanthus plants experienced rapid growth, they sent out new rhizomes that expanded each clump of stems. We planted the miscanthus plugs 30" apart, after two growing seasons they were 14-16" in diameter. The plants reached their maximum height of 11' by October. During November and December the stems began drying out and the leaves fell off as expected. On December 10 the moisture content was down to 30%, by February 17th it was at 15% and ready for harvest.

We harvested the second growth of miscanthus on February 17th, 2013 using a Claas self-propelled forage harvester and row-independent corn head.  The only adjustment needed was to shorten the length of cut to make the miscanthus suitable for bedding.  The forage harvester drove slower than in corn in order to keep the head from plugging.  It would be possible to harvest faster by making adjustments to the header speeds, but we only had 2 acres to harvest. The plot yielded 5.25 tons per acre (at 15% moisture) as weighed on a certified truck scales. 

From February 17th to March 19 I bedded the compost barn with chopped miscanthus on one side and kiln dried shavings on the other.  It's important to note that the miscanthus side was previously bedded with shavings, so the miscanthus never made up more than 50% of the bedding as we were daily mixing the pack with a harrow. After a month of bedding I took samples and temperatures from 8 locations on each half of the barn.  The miscanthus stayed drier (37% moisture vs. 42.5%) and significantly hotter (129°F vs 120°F).  I don't have any doubts about the suitability of miscanthus for a compost bedded pack.

For the third growing season of our miscanthus plot absolutely no work was needed before harvest.  Weeds were nonexistent except a few Morning Glories outside the plot that sent runners up one clump of Miscanthus stems. From May to October the miscanthus plants experienced the same rapid growth as the prior year.  Rhizome clumps were 20-24 inches in diameter.  Stems reached an average of 12' in height with some spots reaching 13' and others 10-11'.  Moisture levels were checked monthly on 11/20 it was 43%, on 12/20 32%, on 1/20 25.5%, on 2/20 16.5%, and 3/14 13%.  Deep snow delayed harvest until March 14.  Yield per acre increased to 6.5 tons (at 13% moisture). 

Research results and discussion:

When applying for this grant, one of the benefits of miscanthus bedding was it's availability when wood shavings were scarce.  Good bedding simply wasn't available from regular suppliers at the end of winter.  In the years since we have been able to find wood shavings year round.  The security of having a homegrown bedding supply may be valuable in the future, but was not a great advantage in 2013 or 2014. 

The bedding trial showed that miscanthus works extremely well in a compost bedded pack barn.  It's suitability for other bedding programs wasn't analyzed, but the physical nature of the particles leads me to belive that it is too prickly to use in freestall dairy barns to replace shavings.

The cost per ton could be calculated in a number of ways.  For this trial we used prime farmland (that would cost $500/acre to rent) but selected an area excluded from manure calculation (which would bring the rental value down).  The establishment costs are prohibitive for making a quick return on investment, but if you can dedicate acreage for decades of harvest the cost/per ton will eventually approach land rental rates plus the cost of harvest.

For the purpose of estimating a payoff period I am providing a per acre expense and income for each year assuming a miscanthus value of $240/ton for bedding purposes:
Growing season 1
  Land rent                    $-500.00
  Soil preparation               -45.00
  Preemergence herbicide   -50.00
  Miscanthus plugs          -4242.40
  Miscanthus planting        -450.00
  Post-emergence spray      -50.00
                                    -5337.40

Growing season 2
  Land rent                    $-500.00
  Post-emergence spray      -50.00
  Harvest                         -150.00
  Value of miscanthus      1260.00
                                       660.00

Growing season 3
  Land rent                    $-500.00
  Harvest                         -150.00
  Value of miscanthus      1560.00     
                                       910.00

Assuming a return of $1000/acre in future years the project would break even at the end of year 7.  This could easily be shortened with finding higher value uses for the miscanthus or the adoption of lower cost planting techniques like automated rhizome transplanting machinery.

Participation Summary

Education & Outreach Activities and Participation Summary

Project Outcomes

Assessment of Project Approach and Areas of Further Study:

Future Recommendations

The yeilds observed in this trial represent the potential for miscanthus in highly productive soils.  It's likely that the cost can be reduced by using marginal cropland that is available for a lower cost per acre.

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.