Depending on where and when tillage is applied, it can both help and hinder soil structure and soil biology. Tillage is not one-size-fits-all, so it’s important to have a specific goal in mind before tilling in the fall or spring.
Illinois-based sales consultant and Certified Crop Adviser Ben Adolph offers the following advice when selecting tillage strategies for your farm.
How can tillage impact soil structure and life?
Adolph: Over tilling can damage soil structure, which decreases pore size and air and water movement. Deep tillage can remove layers of compaction and increase the depth of water infiltration, but certain tillage methods can put a restrictive layer in the soil. In this case, soil compaction may increase, causing restricted root growth and possible plant health issues.
Soil life benefits most from a no-till system, but some farms must balance the need for reduced compaction and diverse rotations with tillage. Match your tillage system to the outcomes you’d like to see on your farm to leverage tillage benefits while mitigating its negative impacts on soil life.
Which tillage system would you recommend?
Adolph: Strip tillage is the tillage of choice from an agronomic perspective. Coverage, resource usage, and input efficiency are optimized under these systems. Strip tillage offers many of the benefits of traditional tillage with few of the draw backs. It reduces compaction and controls residues around the seed bed while avoiding the large-scale soil disturbance and erosion seen with traditional tillage. Strip tillage also allows growers to band nutrients in close proximity to the seed bed. This increases nutrient uptake efficiency by reducing nutrient loss from leaching.
Can I use dry fertilizer in a no-till system?
Adolph: Dry fertilizer nutrients in a no-till system need to be stable and highly efficient to avoid loss due to environmental causes. Nitrogen sources like ammonium sulfate are soluble and in ammonium form, so leaching is minimal. Other nutrients like calcium must be soluble so they are available to make efficient impacts on crop performance.
Which system is best for mitigating soil loss?
Adolph: No-till and strip-till systems, in combination with proper conservation tools like buffers and waterways, will prevent most soil loss. Unfortunately, many of the weather events we are seeing exceed “normal” rainfall totals. Wind erosion during the winter is a major factor if adequate snowfall doesn’t cover the soil. Dirty road banks are common around conventionally tilled fields and are an indication of poor soil structure.
Cover crops are a great tool to help prevent soil loss outside the growing season, especially in strip-till or no-till systems where residues are removed for fodder. This combination of tools will keep top soil and any remaining nutrients intact for the coming growing season.
I want to preserve more soil moisture in our fields. What tillage system is best for managing soil moisture levels?
Adolph: No-till soils retain moisture longer, but may have infiltration issues if soil biology and structure are degraded. Cover cropping in no-tilled soils can aid in establishing a balance of infiltration and drying after rain events.
We often struggle with wet, heavy soils. What should we try to improve drainage and keep compaction to a minimum?
Adolph: Drainage tile is the most effective at improving soil quality issues in low-lying, heavy soils. If this has already been done or is not an option, in-line ripping and cover crops will improve air and water management to a certain degree.
If I switch to a no-till or strip-till system, how can I manage residues to ensure good seed-to-soil contact and even emergence?
Adolph: Residues are a valuable source of crop nutrients. Corn residue, for example, can provide around 17 pounds of N, 4 pounds of P and 20 pounds of K per ton. In low-tillage systems with healthy microbial populations, residues are decomposed quickly, ensuring plants have access to these nutrients in the next season. Residues also provide soil cover, which helps prevent nutrient and soil loss.
Good seed-to-soil contact can be achieved in any tillage system with help from the right equipment. Emergence issues are typically a result of down-pressure issues or general poor planter performance. Proper row cleaners and adequate down pressure will remove most seed-to-soil contact problems.
If you remain concerned about residue issues in spring, use of choppers and chaff spreaders in the fall can help evenly distribute residues across the field. If livestock are part of the farm, fall grazing and baling can also be used to help remove residues. It’s important to remember to replace the nutrients taken off the field in the form of residues with fertilizer in the fall or spring.
Can I use cover crops in a no-till or strip-till system?
Adolph: Yes. Many growers think that cover crops add too much residue if used in a no-till or strip-till system. However, because soil biological activity increases in these systems, the ground is better equipped to handle the increase in residues. Cover crops can also be grazed or harvested for livestock feed, which can alleviate residue concerns on farms with animals.
I’m an organic farmer and often have to balance the benefits that tillage brings to weed control, and the disadvantages it can have regarding soil loss and soil structure degradation. Is there another way I can effectively terminate weeds while also preserving my soil health?
Adolph: Cover crops are the ultimate tool in combating weed pressure and soil loss due to erosion. It’s a BOGO [buy one, get one] special.
How might tillage impact fuel usage?
Adolph: Typical conventional tillage systems consume 2 gallons more per acre in fuel than no-till and strip-till systems. The strip-till machine at our Milledgeville location requires about 0.2 to 0.4 gallons per acre of fuel, significantly less that what is typically needed in traditional tillage systems.
Do I need to purchase new equipment to try strip-till or no-till on my farm? What do you recommend I try?
Adolph: Our Illinois location offers strip-till services to farms within 25-mile radius of our Milledgeville office. Application costs are $15 per acre, which can be a significant savings when compared to the cost of a clean-tillage system in the fall. Plus, the fertilizer is concentrated into an 8-inch zone for optimum efficiency.