Final Report for FNE10-697
Project Information
This study sought to identify perennial bio-mass grasses most suitable for farming in high altitude fields with short growing seasons as are found in Delaware County, New York. With the increasing economic and political interest in developing renewable fuels, grass is a natural alternative that can be produced into pellets to fuel clean and efficient pellet stoves. Factors considered in the study include cost of planting, effective yield of method of planting, and quality of the final product. Eight species of common grasses were compared at each step of the production process: planting, growing, pelleting, and burning. The final pelleted products were measured for ash waste residue and for Btu output for each bio-mass product.
Farmers who wish to grow bio-mass with the lowest investment can use existing fields with very little up-front investment. Marketing this bio-mass may be a bit more difficult but if that market can be found or developed, this can be profitable.
The most productive plantings were miscanthus, canary grass and willow. They do require a greater initial cost but the yields can quickly turn a profit. To re-plant an entire field with seed that may have been in corn or another crop, we recommend canary grass over the other varieties we tested.
Introduction:
In the bio-based economy, renewable herbaceous biomass perennial grasses and forbs will become important raw material for conversion to bio-fuels, chemicals, electricity and heat. In this study we are only concerned with pellets to be burned in pellet stoves and furnaces. Grasses consist of constituents which cannot be converted to energy. This material is known as ash and can have a significant affect on the efficiency of stoves and furnaces. The purpose of this study was to see how various grasses performed in the higher altitudes and shorter growing seasons of upstate NY and more specifically, Delaware County, New York.
This study has researched the following areas:
• Preparation
• Plant type
• Planting methods
• Growing conditions
• Harvesting time and method
• Handling systems
• Pelleting process
• Burning efficiency and ash content
The objective is to assess which grasses performed well, from seeding to harvest. In addition this report compares pelleting and burning various grasses.
Cooperators
Research
The grasses and forbs used.
• Tall Wheat Grass
• Switchgrass (Cave in Rock)
• Giant Bluestem
• Indian
• Miscanthus
• Material from existing field. Consisting of mainly cool season grasses, goldenrod and several forbs
• Canary Grass
• Tall Fescue
• Bamboo
• Willow
• Mixed forbs. Consisting mainly of goldenrod, heleopsis, joe pye weed, milkweed and echinacea.
10 acres were split into 10 - 1 acre plots. Our seed rate was 10 pounds per acre. A small amount of fertilizer was added with each seed planting. Miscanthus, bamboo and willow received no fertilizer.
The plantings were done as follows:
Grass Seed used - Roundup sprayed - No-Till or Disc and Seed
Switchgrass - Sprayed with roundup spring 2010 and seeded with no-till seeder June 2010.
Switchgrass - Sprayed with roundup spring 2010 and disc and seeded July 2010
Canary Grass - Sprayed with roundup fall 2009 and seeded with no-till seeder June 2010
Tall Fescue Sprayed with roundup fall 2009 and seeded with no-till seeder June 2010
Indian Grass - Sprayed with roundup spring 2010 and disc and seeded July 2010
Giant Bluestem - Sprayed with roundup spring 2010 and disc and seeded July 2010
Tall Wheat Grass - Sprayed with roundup fall 2009 and seeded with no-till seeder June 2010
Tall Wheat Grass - Sprayed with roundup spring 2010 and disc and seeded July 2010
Mixed Forbes - Sprayed with roundup fall 2009 and seeded with no-till seeder fall 2009
Bamboo, willow and miscanthus were plants, cuttings and rhizomes planted by hand and not seed.(Footnote 1) They were planted in spring 2010. Since bamboo and miscanthus are warm season grasses, they must be dug when dormant in early spring. Digging and transplanting at any other time can dramatically affect their growth and vigor. The existing hay field was not touched and was left to grow naturally. Willow cuttings must be fresh and dormant when planted for success. The root cuttings were put 8 inches in ground with just the top above ground. They need to be planted with buds up and in firm contact with soil.
Estimated cost per acre to plant
• Grass by seed using No-Till $145
• Grass by seed using disc and seeder $185
• Miscanthus using Plugs (Footnote 2) $1,800
• Willow 8” cuttings (Footnote 3) $1,900
Hiring bio-mass firm to plant 100 acres or more would reduce these costs.
Estimated tons per acre (Footnote 4)
• Switchgrass 5-7
• Canary Grass 3-5
• Miscanthus 12-18
• Mixed Forbes 3-4
• Existing Field 4-6
• Willow 3-5
Our first observation was there was little or no difference in germination and weed control whether we sprayed fields with roundup in fall or spring. Plots that had been turned over using a disc showed a greater variety of weed species. The weeds also germinated faster than the bio-mass grass seeds. After seeds had germinated and grown to about 4-6 inches we performed the initial cutting to control the weeds. The plants were inspected and the following results we noted.
Grass Type - Till Type (Footnote 5) Germination (Footnote 6)
Switchgrass - No-Till - Uneven
Switchgrass - Disc - Fair
Canary - No-Till - Uniform and dense
Tall Fescue - No-Till - Poor
Indian - Disc - Poor
Giant Bluestem - Disc - Poor
Tall Wheat - No-Till - Poor
Mixed Forbes - No-Till - Uniform and dense
We mowed again 4 weeks later and left the grasses planted by seed to grow on until frost. The miscanthus, bamboo and willow all showed excellent survival and growth rates. These were not mowed at all in 2010. A mature planting of miscanthus gigantus already existed on the farm and that grass was harvested and stored for testing in 2011.
Conclusions after 2010 growing season
Due to the poor germination rates of tall fescue, indian grass, giant bluestem and tall wheat grass, we concluded that these grasses would not be good candidates for bio-mass in Delaware County, NY. Warm season grasses need a higher soil temperature to germinate well and this could be the reason for the poorer germination of these grasses. Please note; we did leave the plots of these grasses to grow on in 2011 and the growth and density of the grasses did not improve much. There did not seem to be much difference between no-till and disc and seed except in time and money. No-till was quicker and less expensive to plant the seeds.
2011
The bamboo plants died back to the ground. They sent up new shoots but they turned out to be smaller canes than those initially planted in 2010. At this point we eliminated bamboo as a good bio-mass source for short season climates. The grass plots were allowed to grow on in spring and early summer and were not cut until late July. The grasses were left for 5-7 days to dry out and leach as much as possible non-combustible materials back into soil. The material was then picked up using conventional haying equipment. The material came out of the field at between 12-18% moisture. The miscanthus was the driest and canary grass had the highest moisture content. The willow was not cut down but rather hand pruned to gather material to use in the pelleting process. Willow growth was moderate in year two but showed aggressive secondary growth after pruning. The miscanthus was not cut at all in 2011 and showed significant growth. The miscanthus had reached about 7-8 feet by mid August and had increased to a 10-16 canes per plant. The mature miscanthus on the farm have up to 100 canes per plant and a height of 14-16 feet. Warm season grasses and willow take at least three years to reach maximum yields. Cool season grasses like canary grass, produce higher yields in the first two years than the warm season grasses.
Pelleting
The grass bio-mass was reduced in size using a tub grinder and hammer mill. A California pellet machine was used to make pellets. No additional drying was needed as our grass was in the appropriate range. No binding agents where added. (Footnote 7) This allowed for stricter comparison of the quality of the finished pellet.
The quality of finished pellets was as follows: (Footnote 8)
• Switchgrass - Fair
• Canary Grass - Good
• Miscanthus - Good
• Mixed Forbes - Good
• Existing Field - Good
• Willow - Very Good
Burning
Pellets were burned using a multi-fuel stove. This stove is designed to burn grass, wood, corn, and other bio-mass. The type of stove most commonly used by consumers, however, is designed for wood pellets only. Newer stoves which are made to handle higher ash are now being produced. These stoves are designed to handle clinkers and ash better than older stoves designed to burn wood pellets only. This should increase the saleability of grass based bio-mass pellets in the future.
One hundred pounds of pellets were burned for each grass. Total ash produced was recorded to determine Btu output of each bio-mass product.
Type % Ash Content
• Switchgrass 3.3%
• Canary Grass 6.2%
• Miscanthus 2.1%
• Mixed Forbes 4.2%
• Existing Field 3.6%
• Willow 1.1%
Grass bio-mass will produce about 16,000,000 Btu’s per ton minus the percentage of ash. The chart below shows the Btu output that was recorded based on amount of ash after 100 pounds of each bio-mass was burned.
Type Total Btu’s/ton
• Switchgrass 15,472,000
• Canary Grass 15,008,000
• Miscanthus 15,664,000
• Mixed Forbes 15,328,000
• Existing Field 15,424,000
• Willow 15,824,000
Conclusions after 2011 growing season
Growth was good in all grasses and willow with one exception. Switchgrass lagged behind the others. It remained uneven and did not fill in as the others did. Harvesting was the same for all except the willow which cannot be harvested with conventional haying equipment. Handling moisture content was not difficult if grass was left long enough to leach minerals before harvesting and stored properly. Material pelleted soon after harvesting and not stored over a long time had higher moisture levels and were easier to pellet.
Since the ash contents did not affect the Btu output dramatically, depending on investment objective, any of the six bio-mass products we harvested can produce a good pellet. However, switchgrass would be the one that might be the most difficult to establish in short season locations like Delaware County, NY. Canary Grass, which is a cool season grass, performed the best out of all the grasses planted by seed. For small bio-mass plantings, we cannot justify the expense of purchasing specialty hybrid grasses.
Farmers who wish to grow bio-mass with the lowest investment can use existing fields with very little up-front investment. Marketing this bio-mass may be a bit more difficult but if that market can be found or developed, this can be profitable.
The most productive plantings were miscanthus, canary grass and willow. They do require a greater initial cost but the yields can quickly turn a profit. To re-plant an entire field with seed that may have been in corn or another crop, we recommend canary grass over the other varieties we tested.
1) Bamboo – plants. Miscanthus – plants and rhizomes. Willow – 8 inch cuttings.
2) Based on 20 cents per plug and 6000 plugs per acre plus labor and machinery costs
3)Based on 25 cents per cutting and 6000 cuttings per acre plus labor & machinery costs
4) Tons per acre were calculated using mature plant size and not actual harvesting of the bio-mass plots in 2011.
5) Till Type: No-till is direct seeding without discing, plowing or tilling the soil.
6) Germination: Uneven was germination was good in some areas and little or no germination in others. Poor was little or no germination throughout planting plot. Uniform & Dense was even germination throughout planting bed.
7) Binding Agents are used when material has a low lignin level. Lignin is a compound found naturally in plants that assists in holding bio-mass together after it has been pressed into pellets.
8) Quality – Poor was excessive fines and softer pellet. Good had less fines and pellet was denser. Very Good was little fines and the pellet was very dense.
We concluded that farmers can utilize existing fields and produce bio-mass without large investments of time and money. Existing grasses and forbs do provide a quality pellet that can be efficiently burned in the newer pellet stoves that are designed to burn grass pellets. Yields will be lower but as discussed below the yields can be increased over time with a small investment of money and time.
For farmers who choose to start a large bio-mass operation converting 100’s of acres, we would recommend hiring out a bio-mass firm to establish your fields. There is special equipment that is used to plant miscanthus on large acreage. The increase in potential dry ton yields in large operations should justify the cost of planting many fields with the specialty bio-mass grasses.
Education & Outreach Activities and Participation Summary
Participation Summary:
Article on report has been submitted to Country Folks, Lee Publication. It will appear in an October 2011 issue. Article has also been submitted to Cornell Cooperative for publication. A seminar presentation will be made with Cornell Cooperative this fall. A field presentation will also be held June 2012.
We will continue to monitor the development of the fields recording growth and yields from the grasses & willow. We will also be available for consulting with farmers and landowners looking to grow bio-mass.
We will be working on techniques to increase stock of grass plugs and willow cutting for transplanting into fields.
In addition, we will be available to give presentations to farming groups and organizations. Presentations will include the results of this study.
We will be planning field days for interested parties to see how the grasses grow and are harvested.
Project Outcomes
Potential Contributions
Many unproductive fields in Delaware County can be used for bio-mass and provide additional income for farmers and landowners. This bio-mass may also be used on the farm for heat, bedding or other potential uses.
The more bio-mass that is available,the greater chance of investment capital coming to Delaware County to establish pellet mills. Not only will this produce additional income for farmers but also create jobs for local residents.
Planting techniques
Willow
To start cuttings directly in the ground:
Note: This is easy if you can keep the soil moist.
Note: The soil should not be soaking wet and remain that way for any length of time. This can result in failure to grow, particularly if the weather is cool.
Prepare the planting area:
If you have clay soil the cuttings may be kept too wet and therefore may rot before roots can form. Either push cutting 8 inches in moist soil or if area is very wet dig holes of about 2" in diameter and fill with sand. That allows the water to drain away. Plant the cutting in the middle of the hole. They should be happy in the clay soil, but they need to grow roots first and wet soil hinder root growth.
Do not add compost to the planting hole, nor to heavily amend the soil with organic materials. That would tend to hold water around the cutting, and in cool weather it may rot.
The soil should be soft for ease of pushing the cutting down into it, and to ensure that the bark of the cutting is not damaged weeds need to be kept away from the cutting for the entire first season. Grass must be kept under control. Use of a weed-suppressing mulch or woven landscape cloth is recommended.
Timing of planting:
The ground must not be frozen nor should it be very cold (the cuttings may rot). Plant when days are comfortable.
To plant simply push the pointed end into the soil (buds pointing upwards), leaving two or three buds visible but no more than about 1 inch above the ground. Firm the soil around the cutting. The soil must not be allowed to dry out.
The cutting will initiate roots all along its length, wherever it is in contact with the soil.
Miscanthus
Purchase plugs or rhizomes. It is best to plant them out in propagation beds. Dig plants each year splitting rhizomes. Use some rhizomes to keep planting beds growing.
Use other rhizomes to plant in long rows through bio-mass fields. Spray strip with roundup to kill existing grasses. Rhizomes should be planted in mid-May covered with about 1 inch of soil with eyes facing up. The soil should be moist but not wet. Water if soil is dry.
IMPORTANT: Do not mow till hard frost. Warm season grass grow mostly in July, August and September. Mowing any other time will hurt future growth of plant.
Future Recommendations
To increase yields on small scale operations, a combination of grasses would work best. Using an existing field and planting strips of miscanthus would dramatically increase total yield. The miscanthus would spread through rhizomes crowding out smaller and less productive grasses. Since yield is one of the most important factors to success, we concluded this approach to be the best for small scale operations.
Another recommendation would be to setup growing beds to increase miscanthus rhizomes. They can then be dug in early spring and planted in strips in the existing field. This would avoid purchasing large quantities of miscanthus plugs. This will also avoid the need to develop fields by planting seeds.
• Spray roundup on 12 foot wide strip.
• Mark 3 rows 3 feet apart.
• Plant miscanthus plugs or rhizomes 3 feet apart in each row. Must be done as they break dormancy.
• Miscanthus needs very little fertilizer. Best time to fertilize is in spring when they break dormancy.
• Miscanthus will crowd out all other plants within 3-4 years.
• Repeat process every year with 3 new rows.
Willows can be easily propagated through cuttings taken from existing plants. This will take longer to populate several acres but the costs to establish a good crop will be reduced dramatically. There are hybrid varieties which require that royalties be paid, but many varieties without a royalty attached to them will still produce a very good crop.
Our final recommendation is marketing. Bio-mass pelleting operations are emerging all over upstate NY and they are looking for bio-mass. They may have specific requirements for the types of grasses they will buy. Before making a large investment, make sure you have either found an outlet to sell your bio-mass or have a marketing plan in place. Start small, converting several acres at a time and expand as your market grows.