The ability to place fertilizer and other soil amendments below the soil surface can be a powerful tool for producers in Ohio. Implements that perform this function can vary in horsepower requirements, the level of tillage and soil disruption, depth of fertilizer placement, and fertilizer placement capabilities. However, when considering strip-till with fertilizer banding, one needs to evaluate the equipment setup and implementation process for strip tillage and fertilizer banding. This includes the type of strip-till unit, fertilizer application equipment, and the practicality of adopting these practices on the specific farm or field. This publication provides information on different strip-till units and fertilizer banding strategies to help farmers select the correct setup for their farm operation.
Subsurface fertilizer placement uses strip tillage (i.e., strip-till) to perform the operation with fertilizer placed, subsurface within the tilled strip. Strip-till is a tillage pass that sits between no-till and conventional full tillage. Strip-till implements create narrow strips (typically 6–12 inches wide) while leaving the soil between these strips undisturbed. When the strip-till unit is equipped with a fertilizer bin or cart and associated metering components, fertilizer can be injected into the tilled strip resulting in a banded strip of fertilizer. Potential advantages of strip-till include:
- Increased energy conservation compared to conventional tillage.
- Reduction of soil erosion compared to conventional tillage by leaving residue on the soil surface between the strips.
- Quicker spring soil warm-up compared to no-till that promotes seed germination and plant emergence.
- Soil moisture conservation by maintaining crop residue cover between strips.
- Crop yields are generally similar or potentially higher compared to other tillage systems.
- Better carbon management—strip tillage releases less carbon into the atmosphere and maintains higher levels of soil organic matter.
- Cost savings as a result of some primary and secondary tillage operations being eliminated.
While strip-till has been around for a while, in some cases the capabilities and suitability of these machines for farmers in Ohio is unclear. Selecting the correct strip-till and fertilizer banding units to meet a farm's production objectives is important. Commonly, the wrong unit is selected, not meeting expectations for the farm. The factors below outline the types of equipment on the market today, their potential benefits, and other considerations needed to make an informed decision. With proper technology selection, strip tillage and fertilizer banding can optimize nutrient placement, maximize yield potential, and improve cost efficiency.
Subsurface Placement Benefits
- Places fertilizer in a position readily available for crop uptake.
- Potentially reduction in pre-plant field passes to a single operation, thereby conserving fuel and reducing soil compaction.
- Strip-till, sub-surface, placement equipment creates a more uniform seed bed with better seed-to-soil contact and less trash in the furrow, improving planter performance and emergence.
- Sub-surface placement can reduce fertilizer loads in overland runoff.
- Banded fertilizer increases the concentration gradient, which reduces soil absorption and improves P and K movement to crop roots through diffusion.
Equipment Types and Capabilities
Farmers seeking to reduce nutrient losses and improve soil quality need different options for fertilizer application. Subsurface placement achieves these goals, but equipment options range in function and suitability of use for each producer. Generally speaking, sub-surface nutrient placement implements can be divided into three categories: deep rip and placement, zone mixing, and injection types of equipment. For the sake of differentiating between these options, we define them as follows:
A. Deep Rip and Placement Equipment—applies a fertilizer band (generally 3–8”) of liquid, dry, or anhydrous, before the growing season and usually involves some type of tillage or seedbed modification. Generally able to operate at 3–6 mph in a minimal-till to strip-till environment but induces more soil disturbance than zone mixing or injection types of equipment. This option does provide the ability to address soil compaction from typically 6–12” deep since it is equipped with deep rip shanks.
B. Zone Mixing Type Equipment—creates a tilled zone or strip generally around a maximum of 8” wide by 6” deep. These units use multiple coulters and rollers to create the tilled strip along with the capability of banding liquid or dry fertilizer along with manure. Generally able to operate in the 5–12 mph ground speed range. Typically induces more soil disturbance than injection type equipment
C. Injection Type Equipment—applies a shallow, narrow band of fertilizer (generally 2–4”). Most units can apply liquid or dry fertilizers and anhydrous. These types of implements typically use a single disc for an opener and a gauge wheel to control depth. The single coulter creates an opening of 2–4” to band fertilizer products. These implements can be used in the fall or spring but also at side-dress. Operationally, they can be operated at ground speeds between 7–12 mph (or higher) in a no-till or minimal-till environment. Of all the units listed, these high-speed units generate the least amount of soil disturbance, especially on the soil surface. These units are a great option for no-till farmers wanting to band dry fertilizers subsurface.
D. Broadcast and Incorporate—fertilizer application is typically conducted by a dual spinner-disc spreader, followed by incorporation by a disc, field cultivator, or similar tillage tool. Incorporation can be done any time after the broadcast application but should be performed preferably within 3–5 days.
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Acknowledgments
The authors would like to thank Alex Thomas of FABE and Dr. Josh McGrath of USDA-ARS for providing a review of this publication.
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Originally published July 19, 2018.