February 1996 // Volume 34 // Number 1 // Ideas at Work // 1IAW2

Previous Article Issue Contents Previous Article

No-Till Yield Contest Demonstrates Environmental Stewardship

Yield contests have been used as an educational method to teach production methods, but recognition for participants is usually based on the highest yield. The Knox County Conservation Yield Contest began in 1979 to promote no-till production practices and is still being conducted. Data collected over the fifteen year period (1979-1993) show that contest participants have reduced their use of fertilizers, insecticides, and herbicides while still achieving above-average yields. This yield contest has demonstrated that improved management of chemical inputs can help crop producers become more environmentally conscious while maintaining yields.

F. John Barker
Extension Agent
Agriculture/AMOS Innovative Programs
Ohio State University Extension-Knox County
Mt. Vernon, Ohio
Internet address: barker41@agvax2.ag.ohio-state.edu

David P. Miller
District Specialist
Farm Management
Ohio State University Extension-East District
Caldwell, Ohio

Since 1979, local agricultural agencies and agricultural businesses in Knox County, Ohio have sponsored a no-till corn yield contest to promote the use of no-till production practices. Participation in this contest has varied over the years with an average of forty-four farmers participating annually for awards and prizes based on corn yields. By 1993, no-till production practices were used on more than one-half of the total corn acreage in Knox County and on nearly one-third of the total corn acreage in Ohio. However, the adoption of no-till production practices is often associated with an increased use of chemical inputs and therefore a practice many feel contributes to environmental degradation.

Public sentiment continues to strongly favor farmers using less pesticides. An opinion poll conducted by the Center for Communication Dynamics stated that nearly 60% of all respondents agreed with the statement that "farmers use too many pesticides" (Johnson, 1994). Although increased use of pesticides is often associated with no-till practices, this yield contest has provided fifteen years of actual on-farm data showing significant reductions in chemical inputs with no adverse effects on yields.

Insecticide applications by contest participants during this fifteen year period have exhibited a continuous, significant reduction. In 1979, all fields in the contest received an insecticide application regardless of previous crop, insect population, etc. By 1991, insecticide use by contest participants decreased to a low of 8% (3 fields).

All contest fields received herbicide applications until 1991 at which time a change in the rules allowed contest participants to utilize other conservation tillage practices such as chisel plowing or disking. Following this change, some of the participants were able to substitute tillage for chemical inputs contributing to a slight (8%) decrease in herbicide usage in 1992 and 1993.

Fertilizer rates for Ohio for the period 1979 to 1993 were compared to those of contest participants (Table 1). Results reveal that although fertilizer rates decreased in Ohio, the decline in rates by the contest participants have been much more rapid. Trend analysis indicates no significant reductions in nitrogen or potassium rates and only a slight decrease in the phosphorus rate statewide. A similar analysis of the fertilizer rates of the contest participants showed significant reductions in nitrogen, phosphorus, and potassium rate.

Table 1
Average Yield and Fertilizer Applications for Ohio and Contest Participants (1979-1993)
Ohio Contest
AVERAGE YIELD  - (Bu/A) 112.27 157.49
NITROGEN   - Avg. Rate (Lbs/A) 151.73 184.27
 - Trend Analysis (Lbs/A/Yr) -0.49 -3.27*
PHOSPHORUS  - Avg. Rate (Lbs/A) 75.0 67.2
 - Trend Analysis (Lbs/A/Yr) -0.59** -2.65*
POTASSIUM  - Avg. Rate (Lbs/A) 102.3 90.3
 - Trend Analysis (Lbs/A/Yr) -0.21 -3.55*
* Statistically Significant at a .01 level
** Statistically Significant at a .05 level

Average statewide corn yields for the fifteen year period were also compared to contest yields (Table 1). Contest yields have been consistently higher each year with the fifteen year average yield for contest participants being 157 bushels per acre. The average yield for Ohio for the same period was 112 bushels per acre. Contest participants annually achieved average yields 15-42% higher than the state average yield.

Contrary to widely held perceptions, yield contests can encourage reductions in the use of chemical inputs, thereby resulting in cropping systems which have a reduced environmental impact. The on-farm data collected in the Knox County Conservation Yield Contest over the past fifteen years show contest participants have reduced their usage of fertilizer and pesticides while producing average yields that are consistently higher than average yields for Ohio. The reductions in the use of chemical inputs have taken place even though contest participants are still competing for prizes and awards based solely on producing the highest yield. This yield contest has also provided an essential link between the agronomic educational efforts of the Extension office and the citizens of Knox County by demonstrating that with improved management of production resources, producers can become more environmentally conscious.


Johnson, R. R. (1994). Influence of no-till on soybean cultural practices. Journal of Production Agriculture, 7, 46.