Growing and Propagating Giant Miscanthus Grass for Biomass Production and Natural Resource Conservation

Final Report for FNC10-806

Project Type: Farmer/Rancher
Funds awarded in 2010: $5,979.00
Projected End Date: 12/31/2011
Region: North Central
State: Iowa
Project Coordinator:
Co-Coordinators:
Dennis Kasparbauer
Kasparbauer family farm
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Project Information

Summary:

First of all the robustness and hardiness of miscanthus was impressive. We were pleased to see the growth over the first two years and how well the grass was able to hold up against the drought conditions of year two. There is no question that giant miscanthus can be grown successfully in western Iowa.

The level of effort involved to plant the miscanthus was extensive but reasonable. Any more labor requirements would be costly, but since planning only occurs once per field, the investment over time is reasonable. The labor required to harvest rhizomes is too intense for large plots and mechanical digging and collection would be required. This added expense may prohibit rhizome harvesting from loamy clay soils. Not being able to harvest rhizomes on a large scale greatly adds to the overall expense of miscanthus. If rhizomes can be propagated, harvested, and replanted, it reduces the unit cost of each original rhizome. Without harvesting rhizomes, the unit of all miscanthus plants is fixed and is a major expense for initial planning. It may be feasible for a custom operator to own and lease the proper equipment to do large scale planting and rhizome harvesting, but it would require hundreds of acres to justify such a machine.

The mid population level of 12,000 rhizomes per acre would cost just under $5,000 per acre to purchase and plant. Using our process, this would also require three people for close to three hours of time to plant each acre in addition to the rhizome cost. Beyond a few acres of area to be planted, this process would quickly become time and cost prohibitive.

From the establishment of the three plots, both the mid or high populations are recommended for quick establishment of miscanthus. The low population still did not fill in adequately after two years, and it is questionable how successful a harvest will be after year three on the low population plot. It is difficult to tell to what extent the drought stunted the growth of the miscanthus study, but it was clear the no real harvest could be expected from the entire field after both year one and year two. There were more small bunches of quality miscanthus to harvest after year two, but the ratio of sparse growth to hardy growth was still not at a desirable level. Regardless of the population, plant growth was successful. It will obviously take longer for the low population plot to completely fill in compared to the high population. Based on the first two years of growth, this is also why the medium population plot is ideal for plant spacing. We still expect to see more growth in years three and four if the plot will remain.

The higher population plot was only feasible economically to perform rhizome harvesting. The ratio of dirt to move compared to the number of rhizomes collected is maximized in high population plots and this would be recommended for rhizome propagation. Even greater populations than what was studied could be feasible, or double rows as was suggested separately.

We were not able to perform a full production harvest of the plot due to the very low quantity of grass that was produced after both seasons. Based on how the plots appeared to mature in late season and go dormant, we believe an early spring or late winter harvest would be appropriate. The grass was not dormant enough in late fall and early winter to perform a harvest, and the grass would be too moist.

Based on the best areas in the plot, after year two, a five-ton per acre harvest could be expected with a good stand throughout the plot. We feel this is limited data to base a final estimation off of due to the significant drought that occurred during year two that significantly stunted the growth of the grass. This does show a reasonable harvest can be expected even in years of extreme drought, but is short of the expected 10-20 tons per acre production yield.

The biomass market has not been mainstreamed in western Iowa at the conclusion of this grant. Cellulosic ethanol plants in Emmetsburg and Nevada Iowa have been commissioned and are under construction, but the market for biomass has not reached SW Crawford County. We were able to work with the local high school to donate biomass to the school to use for cellulosic ethanol experiments and to help educate the agronomy classes on alternative crops and biomass production.

Following the planting of the miscanthus grass, the plot was left as a no-till, minimum disturbance plot. The grass grew from early spring to late fall and went dormant over the winter. The habitat that the grass creates would be very beneficial to small and large wildlife during the growing season. We determined that an early spring harvest is the most realistic method to cut and harvest the grass for processing. This would keep the biomass in the field the longest to allow for natural drying, but it would also leave cover available through winter for any wildlife. Depending on the final realized profits available from miscanthus, it may be a better economic and environmental option when holistically compared to CRP.

Miscanthus grass is an environmental and sustainable crop that can effectively be grown on farmland in western Iowa. The economic benefits are yet to be realized as a valuable outlet market for the biomass has not yet been fully established in Iowa. Overall, the planting of one acre and maintenance for two years cost approximately $7000. The highest expense was the rhizomes required for planting. This cost alone was approximately $5500 an acre. The remaining costs would be reduced on a per-acre basis by including more acres in the operation. The only ongoing cost after the crop is established is the harvesting costs at the conclusion of each season.

The option of propagating miscanthus rhizomes is one effective way to reduce the unit price of rhizomes. This option does require additional equipment, and takes significant time to propagate rhizomes for new growth. This time delay coupled with the fact that three years of growth is required to achieve a profitable crop makes the miscanthus cost prohibitive on high value Iowa farmland.

If miscanthus is a viable crop option for some areas it could be an economical gain for a region, providing work planting and harvesting both the miscanthus grass and the rhizomes. The biomass could be converted to sustainable fuel replacements that also add to the increasing independence and sustainability of agriculture.

Introduction:

The Kasparbauer family farm is located just west of Aspinwall, Iowa, one half mile north of Highway 141 in Crawford County. It is part of the M and M Divide Resource Conservation and Development region. The farm’s total land measures over 700 acres and is used for traditional corn and soybean production in rotation with no-till practices. He remains very involved, lives on the farm, and in addition manages several large tracts of switchgrass for conservation and game and wildlife habitat management. His son, Randy Kasparbauer, graduated from Iowa State University where he performed research with biorenewable resources. Randy now works for John Deere and began farming biomass crops for renewable energy production in 2011.

Together, the Kasparbauers feel that there is promise in being early adopters of biomass production. Several areas of the farm’s land are currently in the Crop Reserve Program (CRP); thus, it is desired to transition the land to dedicated biomass crops. This will be done by replacing switchgrass with a more resilient and productive plant, while still conserving the land resource with limited agriculture.

The project was to grow and evaluate the cultivation of giant miscanthus grass on three 1/3 acre plots. The plot totaled one acre in area of the grass crop. The crop was grown according to conventional practice where herbicide control for weeds was performed, but was the only required pass. No additional fertilizer or tillage was done to the land following the planting of the crop.

The crop was evaluated for two years. Soil samples were taken from each plot and biomass analyses were done on the crop. An expansion of the miscanthus is desired, but based on the initial two years of miscanthus crop performance, prime farmland should not be a target cropland for miscanthus.

Project Objectives:
  • Is miscanthus grass a feasible crop to be grown in western Iowa?
    Are the labor, mechanical, and financial needs of growing miscanthus feasible for a small- to medium-sized farming operation?
    Is growing miscanthus an environmental benefit that can be comparable to ground currently in a CRP program?
    How does planting density affect growth and propagation of miscanthus grass?
    Will miscanthus be able to be harvested at alternative times in a year, how early can the grass be harvested when grown in western Iowa, and what is a realistic harvest volume to expect?
    Is there an established market to sell miscanthus grass?

Cooperators

Click linked name(s) to expand
  • Dr. Emily Heaton
  • John Klein
  • Rob Williams

Research

Materials and methods:
Planting

Miscanthus rhizomes were purchased from New Energy Farms. The rhizomes that we received in 2011 were delivered from Georgia and were of good quality. The rhizomes were of various sizes and color ranging from the size of a pinky finger to the size of a large carrot and color from bright white to dark brown.

Figure 1: Relative size of rhizomes
Figure 2: Rhizomes delivered by New Energy Farms

The rhizome order was placed after the grant was awarded, the rhizomes were shipped April 25, and arrived approximately five days later. The ground was wet and early planting was delayed. A few local row-crops were planted during mid-April but nothing substantial due to cold soil temperatures and wet conditions. Soil temperature as of April 18 was 42 Degrees F, which is warm enough for miscanthus to plant. We waited for the ground to dry up.

The miscanthus plants are noninvasive, asexual rhizomes of the Illinois clone family. The grass is determined to be the best high yielding biomass plants. The plants are also nutrient and water efficient. They use deep roots to access water reserves, and use the above ground foliage to soak nutrients from the atmosphere. When the plant goes dormant in the late fall, the nutrients return to the roots ready for the next season.

We decided to use one area on a North side-hill that is between two terraces for the one-acre plot. The area is a little over one acre. We wanted to avoid critical tile lines to protect the remaining farm ground, and wanted a relatively good area of ground that would not dry out too quickly. We do not irrigate and have clay-loam soils. This is great for growing corn, but we suspected the heavy and dense soil to be difficult for planting and digging rhizomes.

Figure 3: Planting plots layout in one acre area

The one acre plot was separated into three parallel plots approximately 30 feet wide and 500 feet long. For the low population plot, 40 inch centers and 18 inches between plants was the target. For the medium population plot, we have rows 40 inches apart and plants every 9 inches in each row. This is to double the plant density from 8,000 to 16,000 rhizomes per acre. The high population plot will simulate 24,000 rhizomes per acre. This will have double rows on 40 inch centers planted 6 inches apart in each row. We monitored how fast we could plant and how slow the tractor can go to achieve this. The highest population was the maximum population we could achieve with the speed of the tractor in slowest gear and the speed of planting rhizomes.

We chose to purchase a used planter to use for planting rhizomes. It is a two-row Ferguson Lister planter. The Lister planter cuts a deep furrow and is designed to plant corn in the furrow. We modified the planting mechanism so that we can manually feed rhizomes from a seat mounted on the packer wheels.

Figure 4: Modified two-row planter to plant miscanthus. Picture taken during initial fabrication testing

The planter was set to 40 inch rows that worked great for our needs. We had the option to plant double passes on 20 inch centers when completed, but 40 inches gives us room to work between the rows. It was also recommended by New Energy Farms to double up rows when planting for propagation to make next season digging go more smoothly if propagation is the sole desired activity.

Each 1/3 acre plot was planted with a total of eight rows that were planted in four passes with the two-row planter. Planting got started early around 8:30 am on a great spring day of May 18, 2011. We found the rate and effort of planting rhizomes went fairly well.

Figure 5: Planting method for each sub-plot
Figure 6: Rhizome planter loaded and in the ground. Final version of fabricated planter

Of the rhizomes, we received roughly 1,000 to a box. We were able to measure our work to how fast we went through boxes of rhizomes. For the high-density plot, each of the four 500 foot runs took roughly 20 minutes and two full boxes to complete. The low population density plot took only 10 minutes and one box to complete. The middle range plot ran around 1.25 to 1.5 boxes each run.

The planter functioned really well. It dug a four-inch furrow where the rhizomes were dropped. Then, about 2 inches of dirt filled in on top of the rhizome followed by a packer wheel to increase the soil contact. When it was all done there were some good deep furrows in the field. It was visible that some rhizomes needed better cover. We used a field harrow to level the field. This was done and smoothed out the field. The rhizomes after the harrow work were about 4 inches deep in loose packed soil.

Figure 7: Rhizome planting middle population, 40 inch rows, 12 inches apart without cover
Figure 8: Half complete with planting. May 18, year one

The growth progressed well and is covered more in the Results section below.

Soil Samples

Soil samples were taken from each of the plots to evaluate year-to-year changes in major soil elements. A soil sampling tool was used to take samples from 1-6 inches of the topsoil. With the rhizomes active at four inches we expected to see some minimal reduction in soil nutrients due to the growth. No measurable loss in nutrients after the first year, which included heavy tillage for planting, would be preferable for production farming. Heavy loss in nutrient level would be of concern and it would show that additional inputs would be required for maintenance of the miscanthus crop which is undesirable.

Figure 9: USDA soil map for 1 acre plot

Rhizome harvest

Late in March year two we attempted a Rhizome harvest. First, a spline grapple bucket on a skid loader was used to clear a patch and dig up rhizomes. The process when very smoothly, but would not be feasible for very large areas. Something similar to a rake and baler to remove loose material would be more appropriate, followed by a specialized digger in order to effectively dig the rhizome harvest on a large scale.

Figure 10: Rhizome to be harvested
Figure 11: Spline grapple bucket to dig rhizomes

The results of the rhizome and biomass harvesting is covered in the Results section below.

Research results and discussion:
Year one growth and harvest

Following planting of the rhizomes, we waited for growth.

Figure 12: Miscanthus growth. June 12 year one; one month after planting
Figure 13: Miscanthus growth. July 4, year one; two months after planting

After July year one, weed pressure became significant and herbicide control was necessary. A method to reduce volunteer grass may also be needed to more adequately control weeds. We chose not to do any cultivation to reduce between-row weed pressure. This may be required if grass pressure is too significant early in the first season.

Figure 14: Miscanthus growth, September year one; four months after planting

We were very pleased with the first year growth. The grass grew relatively well and was well established after being planted as a rhizome. Other than a few good patches, the volume was not distinguishable from the other volunteer grass so no harvest was made.

Figure 15: Miscanthus growth. October, year one, approx four feet tall

Harvest
Figure 16: First year manual biomass harvest in late December

It was clear after the first year how low of volume the miscanthus grass stalks were compared to the other biomass material in the field. It was expected the miscanthus would fill in the remaining area after additional years of production.

A few heavy patches of miscanthus was harvested by hand and sent in for a biomass analysis. The harvest consisted of cutting the stiff miscanthus stalks with a sharp corn knife and bundling the stalks by hand.

Figure 17: Sample of harvested miscanthus stalks for analysis.
Figure 18: Miscanthus biomass analysis by MTVL Rhizome harvest
Figure 19: Dug up rhizomes

Digging up rhizomes was straightforward and the root balls were easy to remove from the ground and collect after they were loosened with the skid-steer attachment. Doing this on a large scale would require a specialized digger.

Figure 20: Dug rhizomes after water wash to remove soil

The washed rhizomes showed significant growth after year one. These were replanted in a separate plot area and grew similarly to the other year two plants.

Soil Analysis

The soil sample analysis was done by the Iowa State University Soil and Plant Analysis Lab. The results of the first and second soil samples are shown below. It should be noted that the samples were taken from approximately a 0.1 acre grid. Ideally, there would have been time to conduct a final soil test, but weather and time did not allow for one to be done in the final spring season. A soil sample will be taken and the results will be published on the project blog after the final report date. During the first year there was only a notable change in potassium that was seen in each sample from year two from year one. Other values seemed to vary, but with no historical soil data on the plot, the changes were deemed to be insignificant.

Table 1: Soil sample results

Year 2 growth

Figure 21: Rhizome growth. June 1, year two

Early season growth was promising for a great year two crop. The miscanthus began to grow as soon as temperatures were warm enough to support them. The year was abnormally warmer and drier than average.

Figure 22: Miscanthus growth. July 7, year two
Figure 23: Miscanthus growth. August year two, heavy drought pressure

By the fall of year two, a very severe drought existed in the area. This affected all plants in the region including miscanthus. Extreme heat was also experienced with many days of above 100 degree F temperatures. We were pleased to see that it did not die and held up well against other volunteer grasses. The pressure of volunteer grasses were again significant and may have reduced the productivity of the miscanthus due to reducing light, water, and nutrients available to the miscanthus. Using late spring cultivation may reduce this volunteer grass pressure.

Figure 24: Miscanthus growth. October year two

The same good patch from year one that did equally as well in year two. Some new/additional growth was exhibited; we attributed this to the early start on the season and established root systems. The growth was less than what we expected, but we later found from other Miscanthus plots that our plot performance was good when accounting for the drought that we experienced. Overall, the whole patch grew more than in year one, but the height what not what was expected from giant miscanthus.

Year two harvest

Figure 25: Harvested miscanthus year two for high school Ag class

A harvest of year two miscanthus was performed manually like year one. The biomass was used to supply the local high school agronomy classes doing biomass energy experiments. Other small bundles were collected for other supply/market research. We chose a 10 footx10 foot area of a good stand of miscanthus grass in the highest planted population area. A majority of the leaves and tops of the grass had already fallen off the plants. We cut the grass manually about 2-6 inches from the ground and put the harvested miscanthus in a tub.

The harvested miscanthus was weighed at 21.4 lbs. This is the as harvested weight and moisture content still needs to be accounted for. At this harvest rate, it could be expected to record approximately 9,300 lbs of biomass per acre if a full acre was planted at the medium population rate.

The entire acre plot would not record this. This was from one of the best plots in the field, but a plot of how a biomass crop is expected to be when mature.

Impact of Results/Outcomes

Performed and evaluated the establishment of one acre of miscanthus grass. Performed and evaluated the manual harvest of both the grass and rhizomes. Studied how growing miscanthus impacted the farming operation and farm as a whole. Communicated progress publicly, made presentations, and had published media outlets.

Participation Summary

Educational & Outreach Activities

Participation Summary:

Education/outreach description:

• A blog was created that recorded progress of project over time. http://growingmiscanthus.blogspot.com/.
• May year 1– John Klein UDSA NCRS authored a great article on the project to all local media. The article appeared in all local newspapers for 50 mile radius and was mentioned in local news stories on the local radio stations.
• July year 1– Visited by ISU miscanthus expert Emily Heaton
• August year 1 – Invited to talk at Iowa Learning Farm (ISU Extension) about our experiences
• November year 1– NCR-SARE Farmers Forum at National Small Farm Trade Show and Conference in Columbia, Mo. Presented project to date at a small farmer forum.
• November year 2 – IKM-Manning high school agronomy class used biomass to experiment with cellulosic energy.

Article that appeared in local newspapers, radio stations, and online journals:

Energy grass test begins near Manning
June 3, 2011
Farm News
Denny Kasparbauer, and his son Randy, of rural Manning, are investing one acre of land between two terraces to experiment growing giant miscanthus grass.

They want to learn if this 10-foot tall Asian grass can be grown in west central Iowa soils and climate and how it will yield. They are starting an experiment that will last two years and possibly much longer.

Giant miscanthus grass is a huge biomass producer in many parts of the world, producing from 10 to 20 tons of dry matter per acre. This is twice as much as Iowa's native switchgrass, which has been the leading grass biomass grass producer to date.

Miscanthus is a long term perennial but starts slowly, so it takes at least two years to reach maturity. The first year, there is no biomass harvest as the root systems are developing.

The Kasparbauer men hope to produce four tons per acre of dry grass at the end of 2012, and 10 tons at the end of 2013.

In future years as the roots expand and become deeper; they hope to reach 20 tons per acre. Smaller Illinois test plots have reached 24 tons per acre.

This grass is a sterile hybrid that does not produce seed. It is planted by burying three-inch rhizomes in the ground at two inches deep. The grass stems are surrounded by long leaves that drop each fall.

Then the bamboo-like stalks are harvested.

The tall grass stalks can be utilized in two ways - as biomass for fuel or burned for electrical energy production, which is common in Europe; or there is the possibility of converting miscanthus grasses to ethanol by cellulosic conversion.

This process is being studied now with corn cobs at the Poet biorefinery ethanol plant near Emmetsburg.

Because giant miscanthus loses its leaves before fall harvest, that organic matter provides the protective cover plant residue for the fields to prevent erosion.

It is anticipated that this grass will be likely grown on sloping lands that need perennial grass protection and are less favorable for row crops.

The Kasparbauers have divided their one-acre test site into three 30-foot wide strips, each 500 feet long. The first strip has high plant density of 24,000 rhizomes per acre, roughly six inches apart in the 40-inch spaced rows.

The second strip has a medium density of 16,000 rhizomes planted 12 inches apart. The final strip has a low density of 8,000 rhizomes planted 18 inches apart. They will study how fast the plant sends out new rhizomes and fills in between plants and also between rows.

They planted on May 18 into a row crop field that was soybeans in 2010.

To plant the three-inch long stick-like rhizomes, they fashioned their own planter using an old two-row corn planter from the 1930s.
Even at one acre, this experiment is the largest in size in Iowa for biomass production of giant miscanthus.

Iowa State University and the Southern Iowa Resource Conservation and Development Inc. have smaller test plots of different varieties of miscanthus, but no plot is over 12-by-12-foot. There are no other test fields in northwest Iowa.

Because of its form and height, giant miscanthus can produce twice as much biomass as native switchgrass. Giant miscanthus grass has been growing for 22 years in Denmark and has not spread beyond five feet from its original planting site.

This is important to avoid non-native plants that become invasive over time. Because seeds are sterile, only movement of the rhizomes can spread the plant.

Randy Kasparbauer is a 2009 ISU graduate in mechanical engineering. He studied bioenergy methodology as an undergrad.

He also currently works with Deere and Co. in Des Moines.

Denny Kasparbauer lives on the farm and manages a tiling business.

Project Outcomes

Recommendations:

Potential Contributions

Miscanthus grass is an environmental and sustainable crop that can effectively be grown on farmland in western Iowa. The economic benefits are yet to be realized as a valuable outlet market for the biomass has not yet been fully established in Iowa. Overall, the planting of one acre and maintenance for two years cost approximately $7000. The highest expense was the rhizomes required for planting. This cost alone was approximately $5500 an acre. The remaining costs would be reduced on a per-acre basis by including more acres in the operation.

The option of propagating miscanthus rhizomes is one effective way to reduce the unit price of rhizomes. This option does require additional equipment, and takes significant time to propagate rhizomes for new growth. This time delay coupled with the fact that three years of growth is required to achieve a profitable crop makes the miscanthus cost prohibitive on high value Iowa farmland.

If miscanthus is a viable crop option for some areas it could be an economical gain for a region providing work for planting and harvesting both the miscanthus grass and the rhizomes. The biomass could be converted to sustainable fuel replacements that also add to the increasing independence and sustainability of agriculture.

Future Recommendations

  1. Continue to evaluate miscanthus growth. Funding is required to keep miscanhtus grass in production on valuable crop ground.
    Determine proper practices for grass establishment in order to maximize early yields.
    Develop economical outlets for miscanthus to increase profit potential from each acre of miscanthus grown.

Information Products

  • Growing Miscanthus (Website)
  • 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.