Agronomic Hub and Spoke Demonstration Project

George Cummins, Extension Field Agronomist, Northeast Area


ISU has been conducting applied agronomic research across the state for many years. Current extension recommendations have been developed from these research findings. Many of our clients are unaware of the research farm network and the research findings and/or are not convinced that recommendations based on small plot research are appropriate for their specific farming operations.


As an Extension adoption/ diffusion strategy, the Hub and Spoke model was  introduced in NE Iowa in 2000 as part of a state-funded water quality project.  Agronomic demonstrations began in 2003.  From its inception the goals of this effort have been:

    1. To increase awareness of and interest in the research work conducted at NERF and other ISU research farms.
    2. To confirm research findings on-farm using cooperators farming systems.
    3. To introduce cooperators to the various tools used to make crop production and nutrient management decisions.
    4. To demonstrate the economic advantage and potential environmental impact of various crop production and nutrient management practices.

Research projects are conducted at the NE Research Farm (the Hub) and similar replicated trials are established with on-farm cooperators (the Spokes) across the area. The Extension Crop Specialists have been involved in identifying cooperators; helping organize and establish the replicated studies ; assisting with agronomic/ economic data collection; and analyzing, summarizing and disseminating the plot results. The number of demonstrations, cooperators and counties served has increased over time. In 2006, 20 demonstrations were conducted by 9 cooperators in 5 counties.  The demonstrations compare the productivity and profitability of various products and practices. In most cases the demonstrations are replicated and randomized so that the results can be statistically analyzed. The specific issues to be compared are identified by the cooperator. 2006 topics included: Soybeans W/WO seed treatment; Specialty soybean variety comparison; Soybean variety  X response to aphid treatment comparison; Soybean response to aphid treatment; Soybean foliar fungicide treatment and timing of treatment;   Soybean white mold/ row spacing study; Soybeans W/ WO a Fall cover crop; CRW corn varieties with different Bt events; Corn fungicide treatment timing  Bt CRW/ non Bt variety in  C-C and C-Sbn rotations; Continuous Corn W/ WO residue removal and a comparison of corn and soybean production in ridge-till/ no-till systems.  Demonstration data is summarized and published in a Hub and Spokes booklet which also includes related research results from the ISU Research Farms at Nashua and Kanawha and the Howard County Research Farm. This information is widely shared as the booklet, in crop newsletters and media pieces and to add local experience to educational programs conducted by the Crop Specialists involved.

    1. All cooperators indicated an interest in continuing; stressed the need for multi-year data and identified additional topics for future Hub and Spoke Research Projects. This has been a very beneficial learning experience. I appreciate being part of it. This data was collected on my farm using my farming system. I have confidence in the results and have made subsequent management decisions based on them. My results (foliar fungicide application) did not show an economic response. I am now much more skeptical of advertising claims and dealer   recommendations.
    2. On-farm results (Spokes) were generally consistent with research farm results (Hub). I am more confident that recommendations based on small plot research are appropriate for my farming operation. Many new products/ management strategies have not been tested long enough to appear in the Research Farm Annual Reports. My Hub and Spoke trials provide at least one years experience to use in decision making.
    3. The economic analysis of on-farm trials is a welcome addition and helpful in evaluating new technologies and company sales information/claims. The 2006 trials showed limited yield increase and a negative economic response to soybean fungicide/ insecticide ($8-$10/acre) seed treatments; limited yield response that barely covered the cost of soybean fungicide ($2-$2.50/acre) seed treatments; Significant varietal differences in yield and economic response to timing of foliar fungicide applications in both corn and soybeans; reduced stands from soybeans drilled into a rye cover crop but similar final yields.
    4. As a Hub and Spokes cooperator, I have a greater appreciation of the value of ISU research and on-farm demonstrations. As a Board Member of the NE Iowa Ag Experimental Association, I am more comfortable soliciting financial support for the Borlaug Learning Center to be built at the Nashua Research Farm.
    5. I qualified for Tier III in the Conservation Security Program ($45,000/ year for 10 years) because I adopted many of the practices introduced as a cooperator with ISU on-farm demonstrations. Cover crops and residue removal show little yield response in the short-term. Adoption of these practices must be encouraged by CSP incentives and for their long-term conservation/ environmental benefits.
    6. Premiums offered for identity-preserved soybean varieties with special properties attract interest. When one compares the yield of these specialty varieties with popular commercial varieties and includes the extra storage and handling requirements, there is no value-added advantage to me, the producer. I use the information from the local variety trials to critically evaluate production contract proposals.
    7. I had a Hub and Spoke trial comparing Bt CRW/ non Bt varieties in C-C and C-Sbn rotations in part of an 80 acre field (1/2 mile rows). We had a severe windstorm in July that caused severe lodging even where CRW root damage was minimal. Our plots were 8 rows wide matching the corn head and using the combine monitor we could harvest two plots in one round trip. Harvest was behind schedule and the weather was threatening. My area Crop Specialist was riding along collecting data. Our initial passes indicated consistently better yields (11 Bu/ acre) harvesting S to N than N to S. I harvested most of the rest of the field where lodging was severe one-way. This was not an intended outcome of the project but an added economic benefit of participating in Hub and Spoke 
    8. Data collected from the soybean foliar fungicide trials at the HS site on the Howard Co Experimental Farm was included in a national fungicide trial summary compiled by the University of Maryland. Our data also included an evaluation of disease incidence and severity which is useful in explaining yield response to the various treatments. 

July 7, 2007
100 Corn and Soybean Production and Protection

Page last updated: August 2, 2007
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