Location: Natural Resource Management Research2012 Annual Report
1a. Objectives (from AD-416):
Objective 1: Determine the environmental and economic impacts of cover crop and cover crop mixtures in semiarid cropping systems. Objective 2: Develop dynamic cropping systems to help meet bio-energy production needs and increase economic returns while enhancing natural resource quality. Objective 3: Develop multiple enterprise systems that integrate crops and livestock to economically optimize the quality and quantity of agricultural products while maintaining or enhancing soil quality indicators.
1b. Approach (from AD-416):
Multiple methodologies will be used depending on the specific objectives because of the complexity of this integrated agricultural systems research project. Objective 1 will use a modified crop matrix where different cover crops are seeded into a common residue to evaluate the above- and below-ground impact of cover crops on subsequent crops. Objective 2 will use economic analysis, and modeling techniques to develop economically feasible management strategies for biofuels and an Eddy Covariance System to measure CO2 flux as a surrogate for environmental impact of biomass crops. Integration of crops and livestock, Objective 3, will compare the performance of livestock when grazing annual crops in the fall to livestock performance when grazing perennial grasses in the fall. In the first 3 objectives, common data collected will include soil properties, biomass accumulation and soil water use. In addition, data on the impact of bio-char will be collected in Objective 2 and livestock production data will be collected in Objective 3. Economic analysis will be conducted as appropriate.
3. Progress Report:
The location was competitively selected to be one of the initial Long-Term Agricultural Research (LTAR) sites. This selection was based on the location’s productivity, infrastructure, data richness, geographic location and partnerships. The location also had a scientific review in March, 2012. This outside review team determined the integrated crop-livestock systems research was a location strength. A soil scientist and two technicians attached to this project retired this year. A soil scientist from the closed Beaver, WV location was transferred to the location to fill the vacant soil scientist position. The location hired a Headquarters funded post-doc to work on biofuel related issues. The location finished the field portion of research focused on determining the environmental and economic impacts of cover crop and cover crop mixtures on precipitation-use efficiency, soil attributes, and nutritional quality (Objective 1). A producer focused product from this research is the ‘the Cover Crop Chart’ which is available for download on the location website. This unique outreach tool is patterned after the periodic chart and is designed to be an easy to understand method for producers to get information about potential cover crops. It has been downloaded over 1300 times by producers and educators in 20 countries. Work is continuing on developing dynamic cropping systems to meet bio-energy production needs while maintaining environmental quality and enhancing economic returns (Objective 2). Location scientists are involved with the ARS BioChar working group and the Renewable Energy Assessment Project (REAP). As part of these partnerships, scientists at the location contributed to a synthesis paper evaluating the agronomic impact of biochar. In conjunction with ARS researchers in Morris, MN, location scientists developed a method to determine prices and quantity of crop residue biomass that could be supplied to a biorefinery. The location has continued its emphasis on developing multiple enterprise systems that integrate crops and livestock to economically optimize quality and quantity of agricultural products while maintaining or enhancing soil quality indicators (Objective 3). One of the primary concerns with using livestock to graze crops and/or crop residue has been the impact of livestock on soil quality. Research conducted by location scientists indicated livestock did not have a large negative impact on soil quality parameters in the northern Great Plains.
1. Integrated crop-livestock systems maintain soil quality. Integrated crop-livestock systems, which combine crops and cattle, benefit farmers agronomically and economically. An unanswered question, however, is how livestock influence soil quality for succeeding crops. ARS scientists at Mandan, North Dakota compared the soil quality of an integrated winter grazing management system with perennial grass pastures, which are considered the “gold standard” for soil quality. After nine years of detailed observation, scientists determined that the soil quality of the integrated winter grazing system equaled that of the perennial grass system on these northern Great Plains soils. This new information will benefit farmers in the northern Great Plains by assuring them that they can graze crop residue without a negative impact on soil quality.
2. Crop residue supply. Crop residues, materials remaining in the field after grain harvest, are a promising abundant source of biomass for bioenergy production. However, it is important that harvesting crop residues does not harm the environment and is economically feasible for both farmers and biorefiners. ARS researchers at Mandan, North Dakota and Morris, Minnesota developed a method to determine the prices and amounts of biomass that could be profitably supplied to a local biorefinery. This technique identifies specific fields where biomass prices will be profitable. Results for a Minnesota biorefinery showed that farmers could begin to profitably deliver corn stover at prices above $53 per ton, and that transportation costs result in crop residue harvest being concentrated near the biorefinery, concentrating environmental impacts near the facility, as well. These results provide farmers and biomass industry with information and an analytical method needed to evaluate the economic viability of using crop residues for energy production while avoiding negative environmental impacts.
Liebig, M.A., Tanaka, D.L., Kronberg, S.L., Scholljegerdes, E.J., Karn, J.F. 2012. Integrated crops and livestock in central North Dakota, USA: Agroecosystem management to buffer soil change. Renewable Agriculture and Food Systems. 27(2):115-124.