Willow Project Areas
- Willow Production and Harvesting
- Yield Trials and Breeding
- Wood Biomass Supply Assessments
- Environmental Benefits and Sustainability
- Alternative Applications for Shrub Willow
Willow Production and Harvesting
Expanding the Harvesting Window for Willow Biomass Crops (USDA Rural Development and CSREES)
Biomass from willow crops provides a more reliable source of fuel because long-term supply contracts can be established with producers. Many companies want willow as part of their fuel mix so they can have greater control over supply and avoid price fluctuations. However, the current recommendation of dormant season harvesting of willow limits the times of year that willow can be delivered to a plant in relation to other sources of woody biomass.
Willow biomass crops are managed using coppicing as the regeneration technique. Coppicing reinvigorates the growth of plants, can accelerate growth towards the theoretical maximum, and aids other growth characteristics of the plants. In order to capitalize on the positive growth responses attributed to coppicing, harvesting during the dormant season has been the standard recommendation for willow biomass crops both in Europe and North America.
Expanding the harvesting season for willow biomass crops would expand the time period that it can be a part of the fuel supply and increase the number of acres that a single harvesting machine could cover in a single year. This would increase the demand for willow and reduce harvesting costs because capital expenditures for a harvester would be spread across more tons of biomass. This project is making use of existing willow crop trials in NY and MN to test the impact of harvesting willow during different times of the year. The impact of harvesting on survival, biomass production, stem production, and winter hardiness will be assessed.
Reducing Establishment Costs by Reducing Planting Density
(Supported by USDA Rural Development and CSREES)
This project will determine the optimum planting density with the most recently selected willow varieties using a combination of data from existing and newly established field trials and the cash flow model for willow biomass crops (EcoWillow) that has been developed. Establishment costs for willow biomass crops currently account for about 25% of the delivered price of willow biomass. These costs are a barrier to the deployment of willow, especially since a return on these investments is not realized until the first harvest, which typically occurs four years after planting. Reducing planting density from 15,400 to 10,000 stems ha-1 would reduce establishment costs by about $500 ha-1. However, changing the planting density affects other important management decisions and costs associated with crop production.
A lower planting density may lengthen the time required for the willow to occupy the site and may delay the attainment of the peak mean annual increment (MAI) by a year or more, which would delay revenue generation and increase costs associated with the initial investment of establishing willow. Changes in yield and stem size distribution that will occur at different planting densities will influence the efficiency of harvesting operations. To effectively assess the impact of different planting densities on the cost of willow biomass, all these factors (and others) need to be quantified and accounted for in economic modeling efforts. These data will be integrated in the economic model developed in Task 4 to select a planting density that produces biomass at the lowest cost.
Development and Deployment of a Short Rotation Woody Crops Harvesting System Based on a Case New Holland Forage Harvester and SRC Woody Crop Header
Despite the projected increase in demand for woody biomass from short rotation woody crops (SRWC) and the wide array of benefits associated with their production and use, the expansion and rapid deployment of these systems has been restricted by their high cost of production and in some situations a lack of market acceptance because of poor quality chips from first generation harvesting systems. For willow and hybrid poplar SRWC, harvesting accounts for about 1/3 of the delivered cost. Harvesting and transportation combined account for 45-60% of the cost of delivered cost. Harvesting is also the second largest input of primary fossil energy in the system, after commercial N fertilizer, accounting for about 1/3 of the input. Improvements in harvesting efficiency would reduce the delivered cost, increase the net energy ratio and decrease greenhouse gas emissions associated with SRWC production systems.
SUNY ESF has been working to develop harvesting systems for willow biomass crops for over a decade with support from NYSERDA, USDA CSREES and the U.S. Forest Service. Initial efforts using a tractor mounted single pass cut and chip harvester were unsuccessful. Over the past four years the project partners (Applied Biorefinery Sciences, Case New Holland, GreenWood Resources, Mesa Reduction and Engineering, SUNY-ESF and ZeaChem) have worked together to develop and test chips from a single pass cut and chip harvesting system for SRWC based on a NH forage harvester. Significant progress has been made, but the level of effort needs to be increased in order to meet the rapidly growing need for woody biomass from SRWC systems.
The overall goal of this project, which is supported by US Department of energy and NYSERDA, is to build on existing collaborative efforts among the project partners to develop, test and deploy a single pass cut and chip harvester combined with a handling, transportation and storage system that is effective and efficient in a range of different SRWC production systems across North America. The system will reduce the costs associated with harvesting and transportation, provide consistent quality material to meet end users specifications, improve environmental attributes and accelerate the deployment of SRWC. The project will address four specific tasks critical to attaining these goals, each of which has specific objectives.
- Develop, tune, test and deploy a New Holland single pass cut and chip harvesting system that can be used in a range of willow and hybrid poplar management systems across the United States. In this task the New Holland short rotation coppice cutting head will be developed and tuned so that it efficiently harvests both willow and hybrid poplar SRWC across North America. Harvesting will be tested during both the dormant and growing seasons to expand the harvesting window and across a range of stem diameter distributions to increase the range of SRWC that can be harvested and processed with this unit.
- Develop and refine handling systems that will effectively and efficiently move SRWC chips produced with the harvester in task 1 from the field to the end user. Handling systems will be designed and tested to determine the most cost effective and efficient method of moving chips from the NH harvester to the end user. Systems will build on trials of different handling systems that have already been done with combinations of forage wagons and blowers and dump wagons of various sizes.
- Changes in Wood Quality for Chips of Different Sizes Harvested at Different Times of the Year. This task will quantify changes in moisture content and energy content of willow and hybrid poplar biomass chips stored in piles created during different times of the year (dormant and growing season) with different sizes of chips from the New Holland harvester. A biomass supply model for SWRC, including staging, storage, transportation and multiple satellite versus on site processing, will be developed to determine optimal supply scenarios.
- Impact of Harvesting Improvements on the Economics of Short Rotation Woody Crops. This task builds on existing economic models for hybrid poplar and willow SRWC production systems to refine the analysis of the harvesting, transportation, storage and handling systems. A variety of different harvesting-distribution-storage system models will be developed and compared. The development of this model will be used to assess the impact of harvester improvements and changes in the distribution and storage and variety changes based on data collected in tasks 1-3.
Yield Trials and Breeding
Short rotation woody crops (SWRC) can be produced and harvested sustainably to provide a significant portion of the annual production of biomass from herbaceous and woody perennial crops for bioenergy. One such SWRC is shrub willow has several characteristics that make them an ideal feedstock for biofuels, bioproducts, and bioenergy, which include high yields that can be obtained in three to four years, ease of propagation from dormant hardwood cuttings, a broad underutilized genetic base, ease of breeding for a variety of characteristics, and the ability to resprout after multiple harvests. The establishment of thousands of hectares of willow over the next five years will aid in the deployment of heat and/or power production in the northeast and Midwest. A biorefinery that is being tested in the northeast will utilize the autohydrolysis of hardwoods to produce hemicellulose sugars and acetic acid that will later be used in ethanol production.
Yield trials have been planted in seven states and Quebec over the last several years. These yield trials are planted with a selection of elite willow clones that have been developed through breeding programs. The data from these yield trials have and will provide a reliable assessment of the relative performance of clones in different soil types, climates, and under pressure from local pests and diseases. The best performing clones can then be deployed commercially with confidence of reliability and consistent high yield. The objectives of this project are to assess the current and future potential of willow biomass crops across a wide range of sites in the northeast, north central, south central and southeastern regions. The following are yield trial projects currently underway:
- Two yield trials planted in Tully, NY the 1990s have been selected for studying longer term survival and production. The usual time frame for willow biomass crop production is that they are harvested every three to four years for seven rotations. These trials were planted with clones from the University of Toronto, the Ontario Ministry of Natural Resources and Wild Collections.
- Eight yield trials were established from 2005-2008 using new willow clones bred and selected by the SUNY-ESF willow feedstock breeding program.
- Six yield trials were established in 2009 as a part of the Sun Grant Feedstock Partnership Program.
- Six new yield trials will be established in 2010 to expand the geographical range where willow biomass crops are being tested. Sites for these yield trials include Illinois, Indiana, Pennsylvania, and Missouri.
Environmental Benefits and Sustainability
Alternative Applications for Shrub Willow
Designing, Developing, and Implementing a Living Snow Fence Program for New York State
Blowing and drifting snow can be a large problem along New York State’s highways because it creates safety problems and requires frequent plowing and application of de-icing materials. Often in severe storms, snow cannot be cleared from roads as quickly as it covers the road. Snow fences have proven to be effective in catching snow and preventing it from drifting onto roadways. In New York state, structural snow fences have been installed along some highways, and these snow fences are either permanent or are installed seasonally. Structural snow fences can becostly and effect land uses.
Living snow fences are an alternative to structural snow fences and utilize trees and shrubs planted strategically along roadways to control snow accumulation. Living snow fences have been used in other states, and have proven to be very effective in catching snow while improving land use and being more aesthetically pleasing than structural snow fences. This project examines the most effective design and installation of shrub willow living snow fences for use along New York State highways. The project is developing a partnernship with the New York State Department of Transportation (NYSDOT) in an effort to develop a program that will train NYSDOT employees to design and install living snow fences. So far, this project has planted a couple of living snow fences along Interstate 81 and conducted training workshops for NYSDOT workers.
Wood Biomass Supply Assessments
Assessment of Potential Biomass Feedstocks from Forests in NY
In order to determine potential applications for woody biomass from NY’s forests it is important to understand the scale and spatial distribution of the woody biomass across the state. Forests cover nearly 18.5 million acres (18,464,222 acres) in New York state and while there are large areas in the state such as the forest preserve in the Adirondacks and Catskills where harvesting is restricted, there are nearly 15.8 million acres (15,781,242 acres) of forest land producing or capable of producing woody biomass outside of these areas. Based on the current US Forest Service data, the state-wide net annual growth rate on this forest land is 9,551,724 odt.
The objective of this forest biomass analysis was to estimate the sustainable level of woody biomass that could be harvested from NY forests on an annual basis as a feedstock for the production of biofuels. This assessment was carried out as part of the “Renewable Fuels Roadmap and Sustainable Biomass Feedstock Supply for NY”. As part of this assessment, multiple restrictions and limitations were identified and applied which:
- prohibited harvesting in the forest preserve and other protected areas,
- limited the harvest of traditional forest products and additional biomass for biofuels to the net annual growth rate of forests in each county,
- restricted the proportion of tops and residues collected and prohibited the collection dead trees to address concerns related to nutrient depletion and biodiversity, and
- used a sustainable yield model to address concerns related to site conditions, future demographics, or potential development that might impact long term sustained yield management.
Results from the study indicate that large amounts of woody biomass that could be sustainably harvested from NY’s forests. Across the state between 4.8 and 6.4 million dry tons of woody biomass is available for biofuels or other applications on an annual basis. This material is in addition to current harvesting levels for traditional forest products. Hardwoods make up the majority of the material, accounting for about 70% of the total. In order to make effective use of this supply of woody biomass there are a number of issues that need to be addressed including the deteriorating condition of traditional timber harvesting businesses, the fact that many wood energy harvests are supported by saw timber harvests, the impact of local government ordinances on biomass harvesting, the need to implement and monitor the use of Best Management Practices on a site-by-site basis, and the differing management objectives of the more than 500,000 private forestland landowners who own 85% of the state’s forests. As these issues are addressed, woody biomass from NY’s forest for the production of biofuels has the potential to provide markets for low value material, improve forest management, and support the development of new industries in the state.
Figure 1. Potentially available woody biomass from timberland in each county in NY for scenario #1. The total woody biomass potentially available is 4.8 million odt/yr.
Figure 2. Potentially available woody biomass from timberland in each county in NY for scenario #2. The total woody biomass potentially available is 6.4 million odt/yr.