How to Prepare a Field for Planting Corn

Year-round cropland management is essential to optimizing productivity and maintaining soil health. But exactly how you go about properly preparing your field for planting corn will vary based on your management style and soil and weather conditions for your location. 

The following checklist will help guide you through the process of preparing ground for corn and answer some of the questions most frequently asked by growers as they prepare for planting season. 

When should you begin to prepare a field for planting corn? 

Field preparation isn’t limited to just the springtime. It may be helpful to think of field preparation as cyclical, including post-harvest practices in the fall to help manage the seedbed over winter as well as tasks timed just before planting. 

Generally, spring field preparation before corn planting begins one to two months prior to planting, though timing will vary depending on the region and the conditions in your fields.

📸: BASF Contributing Writer/Featuring a tractor planting corn in spring.

5 steps for corn field preparation

While corn field preparation takes planning and preparation, how to prepare a field for planting corn can be condensed into five key steps: 

1. Evenly distribute crop residue after harvest. 
2. Understand the benefits and challenges of your soil type.
3. Soil test for a complete analysis in the fall and/or spring.
4. Evaluate which planting and tilling methods are appropriate for your soil.
5. Apply burndown herbicides if no-tillage is going to be performed.

Read more about what each step entails below. 

Step 1: Evenly distribute crop residue after harvest and remove debris.

If you are implementing crop residue management practices, uniformly distributing crop remains across your field is vital for equipment performance as well as nutrient and organic matter dispersal. Assessing crop residue with next spring's crop in mind is key. Properly distributing crop residue can help maintain consistent soil temperature and moisture levels, mitigating the impact of uneven germination and emergence on your crop's overall productivity.

Additionally, you should remove any other debris (such as large stones) that may damage tillage and planting equipment.

Step 2: Understand the benefits and challenges of your soil type.

Well-drained, fertile soil is most suitable for planting field corn. However, adjusting how and when to plant corn based on your specific soil conditions can help you maximize yield in any soil type. 

For example, light soils that are sandy or loamy typically warm faster than heavy soils, providing a better chance for corn seed to germinate earlier in the season. On the other hand, heavy soils like silt or clay soil retain more moisture and can handle later corn planting times.¹ 

What should I watch for when planting corn in wet soil?

It is critical to ensure you are minimizing risks related to moisture level when planting corn, especially if your soil type tends to hold on to moisture. In the first 24 to 48 hours after planting, newly planted corn seed absorbs moisture needed for germination, but optimal germination occurs only when there is an optimal level of moisture in the soil. 

The recommended moisture level for corn germination is soil with approximately 50% of available water capacity. Using soil moisture testing protocols can help you measure moisture levels and avoid associated risks. For example, planting in soil that is too dry can lead to uneven germination, whereas soil crusting and side-wall compaction can occur if planting in heavy, textured soils that are too wet.

📸: @microgen via Canva/Featuring an agronomist collecting soil samples from the field.

Step 3: Test and evaluate soil in the fall and/or spring.

Soil testing helps eliminate guesswork by measuring the soil's ability to supply nutrients to growing crops. The yield potential for your corn crop may be limited if your land has low soil pH and nutrient deficiencies. To understand how your soil's nutrient levels and fertility measure up, it is recommended that you soil test at least every three years using proper sampling techniques and equipment.²

For example, testing soil pH will indicate if you a need to add lime, a common soil amendment input for locations where soil acidifies over time. Soil testing can help you tailor essential nutrient input applications toward your specific soil analysis results and/or crop observations. Understanding how to calculate the appropriate amount of nitrogen to apply to corn can help you maximize crop yield, while testing soil phosphorus (P) levels can determine if you need to add P before planting or as a starter fertilizer to reach the optimal range for P values (between 20 and 40 ppm).³

When to test your soil 

Testing your soil at different times throughout the year will likely reveal slight variations in the results. Regardless of whether you test your soil after harvesting or before planting (or both), it is important to consistently take soil samples at approximately the same time of the year to ensure you can accurately compare results year to year. 

• Fall post-harvest soil testing: Growers may opt to test soil post-harvest, when there are fewer demands on time and equipment. Fall soil testing provides time to assess test results and plan soil management decisions before the upcoming planting season. For example, if your fall soil test shows excessive acidity and you need to add lime, you can apply the lime in the fall, and it will have sufficient time to react and change the pH before the crop is planted. This may also help you avoid spring planting delays. However, you should be mindful that fall soil test results will differ from spring pre-plant testing due to recent nutrient uptake from the previously harvested crop.
• Spring pre-plant soil testing: Testing soil before you plant in the spring can help you understand the potential nutrient needs of your upcoming crop at the time of planting. Spring soil testing should provide a relatively neutral representation of your soil condition since it has had time to recover from the previous season's nutrient depletion.

Step 4: Evaluate which planting and tillage methods are appropriate for your land.

First of all, should you even till? The two main considerations when making tillage decisions are soil conditions and management. The success of the tillage system is impacted by soil conditions such as drainage, topsoil depth, surface slope, and organic matter. Soil management practices also affect the soil condition and level of degradation. These practices include residue management, crop rotation, nutrient, insect, and disease management.⁴

Should I till in the fall or the spring?

Deciding on tillage timing is largely based on soil moisture levels. If soil moisture is above field capacity, bringing equipment onto the field can cause soil compaction and soil clods, subsequently reducing soil quality and possibly impacting yield potential.

For example, barring unusual or excessive rainfall during harvest, fall soil moisture levels will often be more suitable for tillage than spring conditions, when soil moisture is frequently at field capacity or above.

📸: @ghornephoto via Canva/Featuring a corn field that has been flooded. Flooding in corn fields can cause oversaturated soil conditions, which can restrict development do to drought stress.

Choosing the right tillage equipment can help alleviate soil compaction. In general, you should make your tillage decisions based on your field's specific conditions and keep in mind that delaying tillage can have negative consequences for soil condition and, ultimately, overall crop productivity.

Tillage methods

Different planting and tillage techniques should be evaluated based on your operation’s needs. Here are some examples of several methods and how they work. 

• Conventional tillage: This method uses multiple cultivation passes prior to planting and possibly nutrient and herbicide applications. Multiple tillage passes break up soil clods into smaller particles, which may improve seed-to-soil contact, warm soil faster than fields with less tillage, and potentially lead to earlier germination.
• Ridge tillage/planting: Seeds are planted in ridges formed by the cultivation of the previous crop; crop residue is moved off the ridge, and seed is placed on top at planting.

📸: @IFPRI via Flickr/Featuring a corn field using the ridge planting method.

• Reduced or no-till: Reduced tillage practices aim to reduce soil degradation by disturbing the soil and crop residue only in the row being planted, leaving the rest of the field as intact as possible to maintain soil health and reduce weed pressure. 

Step 5: Apply burndown herbicides

Burndown herbicides can help control weeds prior to planting and reduce the weed seed bank during the growing season. However, misapplied herbicide burndown is directly connected to the risk of crop injury, insufficient weed control, and potential injury to successive crops. Understanding weed species, expected weather conditions, and planting schedules can help you optimize burndown effectiveness. 

If applying burndown herbicides in the spring, it is critical to allow sufficient time for herbicides to act on the weeds before planting without delaying your planting schedule. For example, Sharpen^® burndown herbicide can work as a spring burndown herbicide application without causing corn planting delays while delivering broad-spectrum control of broadleaf weeds.

In certain situations where winter annual weeds may present a threat to crops if not handled soon enough, growers may want to choose fall burndown applications versus spring burndown. Winter weeds are easy to overlook until spring, when mature plants and subsequent seed pods begin to appear. If weeds reach this stage of maturity, you have already likely missed the best window of opportunity for controlling them.

📸:@LuisNunesAlberto via Canva/Featuring an image of Shepherd's-purse, a common weed in grain crops.

Soil testing can assist you in understanding how to apply burndown herbicides, as sandy or coarse soils require a lower application rate than loam or clay soils. 

What about pre-emergence or post-emergence herbicide?

Both pre-emergence and post-emergence herbicides are valuable tools to lessen weed pressure. Proper application of pre-emergence herbicides can minimize post-emergence herbicide applications and control early-season weed competition, saving time if weather conditions or schedules prevent the timely application of post-emergence herbicides.⁵

The effectiveness of pre-emergence herbicides is somewhat dependent on weather conditions, as rainfall within a week of application is ideal for herbicides to effectively move into the soil layer where weed seeds germinate. If rain doesn’t occur during this timeframe, early-emerging weeds may escape herbicide control due to lack of product activation.⁶ Scouting for weed escapes is recommended to determine if a post-emergence herbicide application will be necessary.

Planting field corn successfully

Completing preparation tasks before planting field corn may feel overwhelming, but properly implementing soil testing protocols and using proper tillage techniques, as well as effective weed control and crop residue management practices, will give your corn crop its best chance for success. 

A BASF representative can help guide you through the steps to take to prepare a field for planting so you can get the most out of your corn crop.

Learn more at Grow Smart® Live:

Learn more about corn planting recommendations: 

• Growing Corn: How and When to Plant Corn, Step by Step
• The Essential Guide to Soil Testing in Agriculture
• How a Burndown Herbicide Approach Can Help Production
• Common Pest Threats to Midwest Corn: A Guide

Experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent, or a seed company professional like your regional BASF representative.

Always read and follow label directions. Grow Smart and Sharpen are registered trademarks of BASF. Copyright 2024 BASF Corporation. All rights reserved.

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Endnotes

1. "Growing Sweet Corn [Fact Sheet]." University of New Hampshire Extension, 10 Oct. 2022, extension.unh.edu/resource/growing-sweet-corn-fact-sheet. Accessed 8 Feb. 2024.
2. Larson, Erick, and Larry Oldham. "Corn Fertilization." Mississippi State University Extension Service, 2021, extension.msstate.edu/publications/corn-fertilization. Accessed 8 Feb. 2024.
3. LaBarge, Greg. "Developing Phosphorus and Potassium Recommendations for Field Crops." Ohioline, 18 Oct. 2022, ohioline.osu.edu/factsheet/agf-0515. Accessed 8 Feb. 2024.
4. Al-Kaisi, Mahdi. "Fall Versus Spring Tillage, Which is Better." Integrated Crop Management, 23 Sept. 2010, crops.extension.iastate.edu/cropnews/2010/09/fall-versus-spring-tillage-which-better. Accessed 8 Feb. 2024.
5. Jhala, Amit. "Burndown and Pre-emergence Herbicides for Weed Control in Corn and Soybean." CropWatch, 9 Apr. 2020, cropwatch.unl.edu/2020/burndown-and-pre-emergence-herbicides-weed-control-corn-and-soybean. Accessed 8 Feb. 2024.
6. Hartzler, Bob, et al. "Preemergence Herbicide Application Timings: Pros and Cons." Integrated Crop Management, 9 Apr. 2020, crops.extension.iastate.edu/cropnews/2020/04/preemergence-herbicide-application-timings-pros-and-cons. Accessed 8 Feb. 2024.

This content is being brought to you in partnership with Grow Smart^® Live and contributing guest authors. BASF provides the information in this article as a service to its customers; however, the views expressed by guest writers are their own and do not necessarily reflect the views of BASF.