Does tillage match my farm's needs?

August 5, 2025 | Mikaela Connelly

Key takeaways:

• Temperature and moisture are important considerations when planning a tillage pass.
• While tillage solves some problems, it can also create others; consider timing and depth.
• Reach out to an agronomist or conservation practitioner to weigh pros and cons if considering a practice transition.

Some farmers consider tillage to be an important practice to prepare the soil, control weeds and break down the residue of the previous crop. The goal is to create optimal soil conditions that encourage seed growth and promote the development of crops throughout their lifecycle, resulting in increased yields.

While conventional tillage is one form, no-till, vertical tillage and strip tillage are three others; the best choice depends on equipment, crop, soil, weather and goals.

General pros and cons

Tillage can be helpful as an effective means of weed control compared to herbicides. With increasing herbicide resistance, tillage can help eliminate weeds, unless the weed grows from rhizomes or stolons, such as field bindweed and ground ivy.

Tillage can worsen the infestation of these weeds by scattering pieces that grow into new plants. Tilling helps redistribute nutrients in the soil profile depending on where nutrients are placed during application (i.e. broadcast vs. incorporated). Additionally, nutrient availability can increase slightly as organic matter breaks down but then reverts to normal levels. Tillage can help incorporate heavy residue to allow for easier emergence for seedlings in the spring.

However, tillage can also negatively influence soil health and weed densities. Tilling fractures soil aggregates and destroys soil structure. The loss of soil structure causes an increase in surface runoff and soil erosion, eroding topsoil and depositing sediment in waterways. Even in fields not prone to water-mitigated erosion, tillage (especially in the fall) can allow for wind-mitigated erosion that can have a long-term impact. This sediment can transport nitrogen and phosphorus from fields into lakes and streams, which can lead to water quality concerns.

Additionally, tillage can cause a hardpan and increase soil bulk density, which is a measure of compaction. If there is an increase in compaction, the plant's root system could be impacted, thus influencing overall plant health.

Tillage releases carbon dioxide, which influences other soil health factors. For example, soil organic carbon supports the soil biological community because it is a primary energy source for microorganisms. A negatively influenced biological community can affect organic matter decomposition and symbiotic relationships.

Considerations

There are a couple of factors to consider prior to tilling, such as soil moisture and soil temperature. Both can influence soil structure, tillage depth, clod size and soil compaction.

If tilling wet soil, it's likely residue won't be incorporated, and there is a higher likelihood of increasing soil compaction. Tilling cooler soil can help increase the soil temperature and reduce the amount of fracturing the soil likely goes through.

Fall tillage

If the weather cooperates after harvest, fall tillage can be a better option than spring tillage. Typically, the soil moisture in the profile is below field capacity, so there is a decreased likelihood of significant compaction.

Additionally, the soil temperature is more ideal than the spring, reducing breaking of soil aggregates into small clods. However, tilling in the fall can have some drawbacks. The soil is left unprotected for longer with fall tillage, so there is a higher likelihood of topsoil eroding with strong winds and snowmelt.

Spring tillage

Given all the fieldwork that happens in the fall, some farmers push tillage to the spring. Tillage in the spring has a few benefits. This enables timelier planting, creates a uniform seedbed and speeds up germination and emergence.

Spring tillage helps to create larger macropores which can allow for greater aeration, so the soil can warm up and allow for quicker crop emergence. Spring tillage can also take care of some winter annuals, such as field pennycress, prior to an herbicide pass. However, tilling in the spring increases soil compaction. Soil compaction can limit some nutrients to the growing plant like potassium. Potassium is immobile in the soil and less available in compacted areas due to the inability for plant roots to explore compacted soil effectively. Tillage in the spring creates a variety of sizes in soil aggregates, but fine aggregates, in addition to spring moisture, can cause crops to be more prone to crusting.

Your approach

Tailor tillage to fit your farm's needs. Tillage can be a helpful tool to solve problems (nutrient distribution, herbicide resistant weeds and seedbed preparation), but tillage can also induce problems for your field (compaction, reduced organic matter over time and erosion) depending on timing and depth.

If you are considering transitioning from one tillage type to another, contact Iowa Soybean Association's research or conservation agronomists for support.

Written by Mikaela Connelly.

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