As we enter spring, many farmers are ready to till their soil. However, tillage does harm as well as good. Producers will need to weigh the advantages against the disadvantages.

Although, by now, a plan of action should already be in place, some of this information may be relevant for some farms.

The disadvantages to tillage are fairly obvious. Tillage costs time, which has two implications:

• You will not be able to use that time to do something else

• You will be delaying your planting.

By not tilling, you cut your labor investment per acre about in half.

The next disadvantage is especially significant in light of current fuel prices. It costs about 3.3 gallons to moldboard and harrow an acre, and about 2 gallons to chisel plow and harrow. The equipment you use for tillage needs to be maintained and replaced over time, and your tractor also wears more. For conventional tillage, this costs about $16 per acre, and for reduced tillage about $7 per acre.

Tillage causes substantial organic matter loss, causing it to be compared to stoking a fire. The addition of oxygen into the soil during tillage causes the aerobic bacteria to rapidly consume soil organic matter. Studies in the Midwest showed tilled soils lost 200 pounds per acre per year of organic matter with moldboard plowing, gain 200 pounds per acre per year with chisel plowing, and gained 1,050 pounds per acre per year with no-till in corn-soybean rotations.

The stability of soil structure, also called soil tilth, is directly dependent on soil organic matter content, presence of fine roots, fungal hairs, and breakdown products of crop residue. Tillage affects all of these negatively.

Additionally, soil biological activity is typically twice as high in a no-till system with high residue cover compared to a clean-tilled soil. You will typically find twice as many earthworms in no-till compared to conventional tilled fields.

To adequately evaluate the question of tillage for your farm, the advantages have to be considered as well. The soil will warm up quicker if you till, resulting in a faster start of the crop. This may result in a yield increase in corn after corn, but not if you have little residue. Row cleaners and zone tillage can be used in reduced tillage systems to overcome this.

Tillage does enable a producer to incorporate manure. This is probably one of the most important reasons to till. The incorporation reduces odor and nitrogen losses from surface-applied liquid manure. The incorporation should take place within 24 to 48 hours after application to gain maximum benefit in these areas.

An obvious benefit is the ability to conventionally plant your crops. If your planter or drill is not set up for no-till and cannot handle residue or firm soil conditions, you will have to till your field.

Additionally, tillage is the most effective remedy to eliminate slug problems. This can also help to reduce residue-related diseases. Some diseases such as gray leafspot survive on crop residue. You will have fewer problems from these if you bury all residues under the soil.

Finally, tillage can be used to alleviate compaction. If you have rutted up your fields, you probably have to smooth them out with tillage. However, tillage also stimulates the formation of a "plow pan" just below the depth of plowing.

In the end, each farm is different. No one solution will work for every farm. In many cases a combination of both is the solution. Whatever practice is used, careful evaluation to yield data and a cost analysis will help to make the decision easier in the future.

Luke Fritz is executive director of the Butler County Farm Service Agency.