Bioenergy and Diversity from Sustainable Systems and Crops

2011 Annual Report for LNC08-293

Project Type: Research and Education
Funds awarded in 2008: $138,638.35
Projected End Date: 12/31/2011
Region: North Central
State: Iowa
Project Coordinator:
Sarah Carlson
Practical Farmers of Iowa
Dr. Rick Exner
Practical Farmers of iowa

Bioenergy and Diversity from Sustainable Systems and Crops


2011 Progress Report

This project has completed the third year of data collection and outreach activities to bring sustainable agriculture further into the public discussion of energy options by demonstrating a basic, practical cropping system that uses a fraction of the energy inputs as continuous corn and provides a net energy output that can be essentially the same while also supporting a diversity of farm enterprises.
Although the price of energy has recently decreased compared to its price three years ago it is still a major expense for a farming operation. The cost of energy continues to be unpredictable. This project compares two practical Midwest cropping systems to explore the difference between energy use to grow and harvest crops, energy used to process those crops into biofuels and the resulting net biofuel energy and fossil energy ratio. Cropping systems with three or more crops use a fraction of the energy inputs as compared to continuous corn and provide a diversity of farm enterprises. Klepper et al. (1977) paired 14 Midwest organic farms with comparable farms not using organic practices, finding that the organic farms produced corn for roughly 36 percent the energy inputs per bushel used on the conventional farms. As noted, nitrogen fertilizer is the greatest single energy input in corn production. In the Klepper study, all farms whether organic or conventional kept livestock and applied manure. Thirty years later, these two types of farming have diverged. Many conventional row crop operations do not have access to manure, and N fertilizer rates have risen. The energy footprint of agriculture is an issue that SARE has always kept alive through research and demonstration projects. Practical Farmers of Iowa field days and workshops in 1992-1993 (LNC92-044) showed that farmer cooperators saved the energy equivalent of 12 gallons of diesel per acre by reducing nitrogen fertilizer an average of 50 lbs per acre. On-farm energy conservation and production continues to be a top priority for PFI members.

Objectives/Performance Targets

Short-term Outcomes: PFI’s media outreach, farmer field days, Dordt College field days and workshops and Annual Conference sessions has introduced the idea of energy savings through various practical on-farm methods to farmers, future farmers, and others including students so they can become familiar with techniques and technologies that farmers and communities can use now and near-term to increase energy independence.

Intermediate-term Outcomes: Farmers and others make informed choices that sustain the environment and are profitable in light of energy costs and their effects on agriculture commodity prices. As PFI’s Energy program continues to develop from the opportunities available through this grant we have had an explosion of cooperators interested in a couple different types of on-farm energy projects. One group of farmers started with baseline data to measure and understand how much current energy their farm is using. Once baseline data is obtained, a second group is implementing changes in the farming practices to conserve energy. A third group is looking at energy generation on farm to reduce dependence on off-farm energy inputs. In addition a PFI with Dordt College established side-by-side farming systems to compare the energy used and produced in the form of bio-fuels from two different farming systems. One system a widely used corn on corn and the second a gateway to sustainability rotation including corn, soybeans and oats and red clover. Several outreach activities have been accomplished from this study.

Long-term Outcomes: The public and public policy view a sustainable energy future and sustainable agriculture as inseparable.



To achieve the short-term and intermediate-term goals PFI has a long history using field days to start the conversation about on-farm research interests including energy conservation and also the transfer of knowledge between farmers who are actively making changes. In addition to completing the various media and outreach deliverables Dordt College finished the third year of data collection and preliminary results are reported in the second part of this report.

Field Days and Workshops
1)90 Dordt College students and farmers attended an evening field day on August 31 focused on results from several projects Dordt College is conducting on their college’s farm. Chris Goedhart along with Dordt College Students and Rich Schuler, PFI on-farm energy consultant, presented about the Gateway to Sustainability SARE project. See a picture of the Cropping Systems plots here Read more here about the general topics discussed at the field day:
2)45 farmers attended a field day at Francis Thicke’s farm on August 27, 2011 to hear about several different on-farm energy projects that Francis and other farmers were testing on their farms. Read more here:
3)140 farmers attended a field day at Harn Soper’s farm on October 21, 2011. Rich Schuler is working with the Soper’s to design a composting system that creates heat and gas to keep the greenhouse heated without using off-farm energy. The greenhouse location is pretty far from an electrical line so that allows the farm to be creative in how they will “fuel” the system because running a line to the building will be expensive. Read more here:
4)40 farmers attended a field day at the Marsden farm study at the Iowa State University Agronomy Farm on September 13, 2011 to learn more about the economic and energetic comparisons of different cropping systems. Read more here:
5)35 farmers attended a PFI Annual Conference session focused on the results of the Marsden Farm study that is part of this SARE grant as well. Powerpoint presentations of the presenters can be found at

On-farm Research Projects
Tom Frantzen—-Groundtruthing Changes – Solar thermal & gassification (corn cobs)
Eric Franzenburg—-Groundtruthing Changes – CoolBot based Walk-In Cooler & Biomass burning (shelled corn)
Craig Griffieon—-Farm Metered Energy Analysis – Getting Baseline Data
Bill Pardee—-Groundtruthing Changes – Solar PV
Harn Soper—-Groundtruthing Changes – CoolBot based Drive-In Cooler
Francis Thicke—-Groundtruthing changes – Solar thermal

Newsletter Articles
1. Vol 27, No.1, Winter 2012, “Solar Photo Voltaic pays off for PFI members” (Rich Schuler)
2. Vol 26, No.4, Fall 2011, “Bioenergy and diversity from sustainable systems and crops” (Rich Schuler)
3. Vol 26, No.2, Spring 2011, “PFI Member refuses to be held hostage by oil prices” (Patrick, Burke)

Impacts and Contributions/Outcomes

Gateway to Sustainability Cropping Systems Comparison Study:
The centerpiece of the grant deliverables as been the cropping systems study that PFI established with Dordt College in Sioux Center, IA. These results are preliminary.

To compare these systems in a controlled, side-by-side experiment Dordt College in northwestern, IA established two farming system treatments in 2008. The treatments included: a continuous corn (CC) system versus a gateway to sustainability (G2S) corn? soybean ? oats with red clover rotation. Dordt College documented all field operations for planting and harvesting and the inputs applied to the different treatments (Table 1). Once the crop was harvested, yields (corrected for moisture content) were reported. PFI staff used the documented field operations, input information and harvested yield data to create a fossil fuel flow chart of the energy that Dordt used to grow the different farming systems. Then PFI staff used published literature to calculate the amount of energy needed to convert or process the corn in both systems into corn ethanol and the soybeans from the G2S system into bio-diesel. PFI staff also estimated (based on published literature) the amount of renewable energy from the ethanol and the bio-diesel products. Since the G2S system is a three-year rotation the corn, soybeans and oat/red clover crops are each only a third of the total area (calculated to an acre) each year. In contrast, the continuous corn system is 100% of the total area each year. This difference was accommodated by assigning 100% of the continuous corn plot as the effective-area, and designating 33.3% of each G2S component as the effective-area. Using this method PFI adjusted the resulting yields of the crops from the rotation.

The energetic differences between the two farming systems were calculated. The diesel equivalents for each crop year’s field operations organized into preharvest machinery, seed/inputs and harvest machinery were estimated from Iowa State University Extension publication PM709. The energy usage to produce the crops was calculated from the diesel equivalents in the preharvest machinery, seed/inputs and harvest machinery. The energy used to process the crop into ethanol or bio-diesel was also calculated and the energy produced from the resulting ethanol or bio-diesel biofuel. Two separate equations were used to summarize the data reported in table 2.

Equation 1) Energy Efficiency = Total Bio-fuel Energy Output / Total Energy Input: where Total Energy Input = Total Bio-fuel Energy Output / Farm Energy Cost of Production reported as a dimensionless number. This value is a ratio of the amount of energy returned as either ethanol or bio-diesel for each unit of energy put into the system, specifically in the processing, planting and harvesting of the crop.

Equation 2) Land Efficiency = Total Bio-fuel Energy Output – Total Energy Input: where Total Energy Input = Total Bio-fuel Energy Output – Farm Energy Cost of Production reported in mega-BTUs/Acre. This result provides us with the NET or how much total energy is produced per acre.

Table 2. References used to calculate table (Berge 1974, Cruse et al., 2010, Hanna 2001, Lammers 2009, Sawyer et al., 2010, Uhrig et al., 1992)
Continuous Corn Gateway to Sustainability Continuous Corn Gateway to Sustainability

2009 1.29 CD 1.77 A 7.86 B 6.02 C
2010 1.31 C 1.72 B 9.43 A 7.32 B
2011 1.28 D 1.76 A 7.01 BC 7.09 BC

Energy Efficiency is a ratio of the output energy to the input energy, while the Land Efficiency is the netted amount of energy per area of land. After three years of this study our preliminary data suggests that the Gateway to Sustainability rotation is more energy efficient than the Continuous Corn system. Within years significant differences were measured. In 2009 and 2011 the G2S rotation was more energy efficient than in 2010 but the Continuous Corn was significantly less energy efficient in all three years than the G2S rotation. In 2010 the Continuous Corn yielded significantly more total energy per acre than any of the other treatments or years. In 2011 the treatments yielded similar amounts of energy, or what we described as the Land Efficiency, as well as in the CC 2009 and G2S 2010. The G2S treatment in 2009 yielded the least amount of total energy per acre.

In 2009 and 2011, the G2S treatment yielded 27% or almost a 1/3 more energy for every fossil fuel BTU expended to plant, harvest and process the crop as compared to the CC system. In 2010 the G2S yielded 23% more than the CC system. The G2S system in all three years was more efficient in terms of energy yielded from energy expended. However it is important to consider the total amount of energy that the different farming systems produced. In 2010 the CC yielded significantly more bio-fuel/A than the G2S. On average between the three years the CC averaged 8.10 M-BTUs while the G2S treatment averaged 6.81 M-BTUs. When both the energy and land efficiency results are considered, the conclusion is that although less total energy/acre was extracted from the G2S system, it required less energy input (i.e., BTUs per acre) to convert energy from a crop to a biofuel. In order to draw an appropriate conclusion, the analysis must include the economics and the CO2 emissions produced by the two different cropping systems. This is a potential area of expanded analysis to follow-up on this project.

Berge, O. 1974. Harvesting and Drying Soybeans A2665 Fact Sheet. Cooperative Extension Program University of Wisconsin.
Cruse, M., et al. 2010. Fossil Energy Use in Conventional & Low-External-Input Cropping Systems. Agronomy Journal Vol 102, Issue 3.
Hanna, M. 2001. Fuel Required for Field Operations: PM709. ISU Extension.
Klepper, R., et al., 1977. Performance and Energy Intensiveness on Organic and Conventional Farms in the Corn Belt: A Preliminary Comparison. Journal of Agricultural Economics V59 N1 P1-12.
Lammers, P. 2009. PhD Dissertation.
Sawyer, J., et al., 2010. Energy Conservation in Corn Nitrogen Fertilization: PM2089i. ISU Extension.
Uhrig, J. and D. Maier. 1992. Costs of Drying High-Moisture Corn. Cooperative Extension Service Purdue


Craig Chase
Agriculture Extension
Iowa State University
312 Westbrook Ln
Ames, IA 50014
Office Phone: 3192382997
Chris Goedhart
Chair, Department of Agriculture
Dordt College
498 4th Ave. NE
Sioux Center, IA 51250-1606
Office Phone: 7127226276
Matt Liebman
Iowa State University
1401 Agron
Ames, IA 50011
Office Phone: 5152947486
Teresa Opheim
Executive Director
Practical Farmers of Iowa
137 Lynn Ave., Suite 200
Ames, IA 50014
Office Phone: 5152325661