On-Farm Research and Demonstration of Ridge Tillage for Sustainable Agriculture

On-Farm Research and Demonstration of Ridge Tillage for Sustainable Agriculture

Summary

Rationale:
A number of Practical Farmers of Iowa (PFI) members use ridge tillage, a system in which crops
are grown on permanent ridges. This is a minimum-tillage system in which the soil is not
disturbed from harvest to planting. Row crops are customarily cultivated for weed control and to
reform the ridges. There is some documentation to suggest the potential benefits and problems of
ridge tillage, but extensive research has not been done.

Objectives:
1) Demonstrate that a ridge tillage row crop production system is economically competitive with
other systems and helps achieve the goals of sustainable agriculture by reducing total tillage, soil
erosion, herbicide use, nitrate leaching and energy consumption.
2) Increase the information base on the management of ridge tillage for sustainable agriculture by
encouraging a science-based, self-help approach to problem solving through replicated research
trials conducted on farms by producers with the assistance of Iowa State University scientists.

Methods:
Over the course of this project, 29 farmers carried out more than 140 replicated on-farm trials to
demonstrate and research ridge tillage in the context of working production systems. They
documented the effectiveness and economics of alternatives in fertilizer rates and placement,
weed management, and cover crops. They also compared ridge-till to other popular tillage
systems, and they utilized the basic ridge tillage technology to move into more complex and
diversified systems like narrow strip intercropping. These research/demonstration plots often
involved collaboration with university researchers and county Extension personnel.

Results:
* Ridge tillage compares favorably with other tillage systems for yields and low-cost production.
* Ridge tillage offers more weed management flexibility than no-till, giving producers a range of
options including, but not limited to, herbicides.
* Ridge tillage is compatible with frugal use of herbicides, including banding, reduced rates, and
substitution by rotary hoeing, cover crops, and cultivation.
* Ridge tillage is compatible with published guidelines for the late spring soil nitrate test for
corn. In 11 replicated trials, there were only three significant yield reductions from reduced
nitrogen fertilizer, and only one of these was attributable to the late spring test. Farmers save, on
average, 50 lbs of N per acre, earned, on average, $4.90 per acre, and conserved the energy
equivalent of 12 gallons of diesel per acre.
* Ridge-till practitioners are learning when to apply manure and purchased fertilizers, where to
place them, how much to use, and what crops are likely to respond. Corn was more often
responsive to row-applied fertilizer than soybeans. Ancillary research by Iowa State University
on many of these same farms suggests deep placement is more often effective in corn as well.

Outreach and Direct Impact:
Over the course of this project, total attendance at PFI (Practical Farmers of Iowa) field days was
approximately 6,000. Each field day was promoted in an individualized press release that went to
local newspapers, television, and radio stations. Field day evaluations returned by producers
showed between half and two-thirds believed the information they gained at field days would
help them institute a new farming practice. Findings were also presented in Midwest farming
publications, and at PFI meetings. Through a cooperative relationship with PFI, Iowa State
University Extension was strongly involved in this project. he PFI/ISU farming systems
coordinator facilitated the trials and field days, and a number of county and area Extension
personnel either attended or presented at project field days. Also involved in field days were
several ISU research stations, the Natural Resources Conservation Service (NRCS), and the
Dordt College Agricultural Stewardship Center.

Collaborators: