Retention of High Levels of Crop Residue on Soil Surface During Tillage

Retention of High Levels of Crop Residue on Soil Surface During Tillage

Summary

Construction of the Residue Saver continued. This implement chops cover crops or picks up surface residue and redistributes these materials behind an attached tillage implement. The Residue Saver was successfully field tested in early August and demonstrated at a field day to over 70 people. A preliminary field trial was run. Currently, design features are being added to extend flexibility of the implement in preparation for on-farm trials in 2002.

Objectives/Performance Targets

To develop machinery that will till the soil to kill perennial weeds and improve crop establishment relative to no-till planting while retaining most crop residue on the soil surface for erosion control and suppression of annual weeds.

To test this equipment in high residue levels created by winter cover crops in agronomic and vegetable production systems, and to evaluate residue coverage, weed control, crop emergence, and productivity in comparison with conventional tillage and no-till systems.

To demonstrate the feasibility and cost-effectiveness of this approach to tillage in on-farm grain and vegetable production systems.

Accomplishments/Milestones

The project has three components–construction of the prototype Residue Saver, on-farm and experiment station trials with this implement, and extension and outreach. Knowledge gained from the trials plus comments from farmers and others viewing the trials and equipment will be used to further refine the machine.

Construction of the prototype Residue Saver. The prototype is a trailing implement with a category II 3-pt hitch built into the rear of the frame for connection to tillage implements like chisel plows and field cultivators. The implement is raised and lowered for transport and connection with tillage implements by means of hydraulic cylinders attached to two pairs of wheels. A PTO-driven flail chopper is suspended near the middle of the frame. A gear box and drive line will continue rearward to allow use of a rotary tiller or spading machine with the implement. The chopper chops cover crops and crop residues and either blows them over the tillage implement, or into a box. The box is used with long, trailing type tillage implements like disks and combination tools. The residue is distributed from the box onto the tilled ground with a high-speed beater. A set of ground-driven spoked wheels mounted ahead of the flail chopper lifts residue into the flail.

The Residue Saver was field testing this year. Tests of the basic implement without the secondary distribution box were extraordinarily successful. The Residue Saver successfully chopped the rye into 8” to 12” pieces and left it uniformly distributed over the soil surface. Lateral drift of residue was small, even in a moderate wind due to downward velocity provided by an arched cover. We modified a chisel plow by placing the shanks on 8” centers and attaching a crumbler and leveling bar. This provided excellent one pass tillage behind the Residue Saver. We used this with a 140 hp tractor, but a 100-120 hp tractor would be sufficient.

Since the initial field tests, we have added a hydraulic suspension on the flail unit to allow easier height adjustment in the field and allow the machine to be quickly lifted over large surface rocks. We also modified the shape and angle of the delivery chute to eliminate the occasional jamming we were experiencing before. The multi-angle swivels that attached the prototype pick-up wheels to the implement were also reconfigured based on the field tests, and a full set of nine of these was produced.

Tasks remaining to complete this winter are further work on the box and beater assembly, and extension of the drive train to accommodate power driven tillage implements.

On-farm and experiment station trials. To obtain preliminary data on residue cover and on how crops will respond to soil prepared with the Residue Saver, we set up a field trial at Cornell University’s Musgrave Farm near Aurora, NY. The field had a standing dead rye cover crop that had been killed in June with glyphosate to prevent seed maturation. Weed cover was substantial, but most weeds were < 6”. Treatments were (1) zone till planting following flail mowing of the rye, (2) conventional tillage consisting of chisel plow, disk and roller harrow, (3) Residue Saver using the single pass implement described above, and (4) Residue Saver with the chisel points on the single-pass implement replaced with 11” sweeps. Plots were 20’ x 100’ arranged in a replicated block design with four replications. Residue management and tillage were done August 11 and 13. Residue cover was evaluated by the beaded string method (300 points per plot) before and after corn planting. Corn was planted on August 14 with a 4 row Kinze planter equipped with trash wheels to clear the row. The same planter was used for zone till, but with 3 Rawson fluted coulters running in front of each planter unit. To assess corn emergence, corn was counted in 2 randomly chosen 50’ row sections on September 12 and 13.

High rates of crop residue cover (61 to 63% after planting) were obtained with the Residue Saver, though this was somewhat less than with zone-tillage (75%). The conventional tillage had an unfortunately high residue cover due to incomplete incorporation by the chisel plow coupled with some lifting of incorporated residue by the roller harrow. Despite high residue levels, emergence in the Residue Saver treatments was not significantly different from emergence in the conventionally tilled treatment. In contrast, corn emergence in zone-till was significantly less than in the conventional tillage and one of the Residue Saver treatments.

In preparation for the 2002 growing season, rye and red clover cover crops were planted at the Musgrave farm, and at two of the cooperating farms (Mandeville and Potenza). Residue at the Van Pelt farm will be heavy corn stover.

Impacts and Contributions/Outcomes

We demonstrated that it is possible to thoroughly till the soil while still retaining high rates of crop residue on the soil surface. This has not been done before. This technology will allow retention of high levels of residue at the soil surface for erosion control and suppression of annual weeds while avoiding many of the problems associated with no-till practices like increased run-off, poor crop establishment, and high use of herbicides.

We demonstrated the Residue Saver and showed the experimental plots during a field day at the Musgrave Farm on Aug. 15. Over 70 growers and agricultural professionals attended. The demonstration generated lively interest, comments and discussion.

John Deere & Co. sent a representative from Iowa to view the machine in the field in August. He expressed enthusiasm and is consulting with their marketing personnel.

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