Planting Date Effects on Corn Grain and Forage Yield
Corn planters will soon be rolling throughout Wisconsin and the Midwest Corn Belt. The annual struggle between field conditions being “just right” and not too wet versus delaying planting to another day will start to weigh on farmer’s minds. In addition, planting delays in the northern tier of U.S. states have greater impact on yield due to a shorter growing season and the added dimension (“double-whammy”) of drying costs at harvest that can occur during cool, wet growing seasons.
Figure 1 shows the impact of planting date on relative grain yield at Arlington. If all corn could be planted on one date, ideally it would be on May 1 or slightly earlier to decrease drying costs. Planting delays to June 1 will lower yields about 30%. However, in some growing seasons, 100% of the maximum grain yield can be achieved planting into late May. Grain yield decreases 0.5 bu/A per day on May 15 and accelerates to 2.5 bu/A per day on June 1.
Seeding Depth Affects Corn Plant Emergence Uniformity and Grain Yield
Rarely do we see a paper published on corn seeding depth and the subsequent impact on grain yield. Precision technologies have allowed for capabilities of variable rate seeding, multi-hybrid planting on the go, and the ability to vary planting depth in real time in response to real-time soil moisture data. In a paper published by Nemergut et al. (2021), corn seed was planted at 1-, 2-, and 3-inch depths on two soil types in Ohio over three growing season (2017 to 2019). Shallow planting resulted in less uniform more extended emergence periods than 2- and 3-inch planting depths. If a plant emerged within 3 days of the first emerged neighboring plants, then there was no effect on plant grain yield. Any plant that emerged more than 3 days after the first emerged plant had a 5% decrease in kernel weight per day. Grain yield per plant increased as planting depth increased. Grain yield per acre was significantly increased by planting depth with seed planted at 2- and 3-inches yielding 8 or 10% more than the 1-inch seeding depth on one of the two soils. Other researchers have also shown improving emergence uniformity can positively increase yield, and that optimum planting depth may vary by field.
Further Reading
Nemergut KT, Thomison PR, Carter PR, Lindsey AJ. Planting depth affects corn emergence, growth and development, and yield. Agronomy Journal. 2021;113:3351–3360. https://doi.org/10.1002/agj2.2070
Setting Yield Goals
The farmer is the only man in our economy who buys everything at retail, sells everything at wholesale, and pays the freight both ways.” – John F. Kennedy
- Farmers aim to achieve the highest potential yield at the best cost to achieve maximum profitability.
- To help maximize profits, some farmers may consider cutting back on or completely cutting out some inputs altogether. These decisions should be calculated and thought through completely.
- Setting realistic yield goals based on calculated decisions and planning ahead, results in maximum profit potential.
Figure 1. Side dressing nitrogen
As a farmer, the goal is to optimize profitability through the maximization of yield potential and cost control; however, this is often easier said, then done. This is particularly true when inputs costs are rising and the crop price is declining or expected to be lower at harvest.
Setting Yield Goals1,2
Realistic yield goals can help the producer achieve the greatest difference between the value of the crop and the cost of producing the crop. Recognize that exceptionally good years are the exception and not the rule. Disregard yields from years where weather related disasters resulted in very poor yields. Keep records for each field as an individual unit. Set your goals 5 to 10 percent above your average yield of the past five years. Utilize field mapping technology to aid in goal setting.
There are a few different approaches to use when determining your yield goals:
- Using previous year’s production. This is a good tactic when a field has been used for several years, particularly when field maps are available for previous years.
- Maximum yield approach. This approach is based only on inputs and management skills. Little, if any, consideration is given to soil potential and variations. This approach can be risky as it doesn’t consider the costs of inputs needed to reach that goal or past yields achieved.
- Soil productivity approach. This approach focuses on soil productivity potential, available water, subsoil moisture, and management skills.
Consider Your Inputs3
Inputs include labor, crop protection products like herbicide and fungicides, equipment, seed, and energy. Most farm inputs are purchased, making production costs susceptible to non-farm economic conditions.
When input prices are low, farmers should attempt to maximize production to reduce the per unit cost of production, with the goal of covering variable costs and as much of the fixed costs as possible. Production inputs are usually known allowing farmers to plan ahead. Knowing in advance can allow farmers to purchase in advance at reduced prices in areas like the cost of land, fertilizer, and seed.
Several Land-Grant Universities have developed spreadsheets that can assist in developing crop budgets for several crops. For example Iowa State University has this site for 2021 budgets https://www.extension.iastate. edu/agdm/crops/html/a1-20.html, North Carolina State University has this site for 2021 budgets, https://cals. ncsu.edu/are-extension/business-planning-and-operations/enterprise-budgets/, and South Dakota State University has this site for 2021 budgets,https://extension.sdstate.edu/crop-budgets
To help maximize profit potential, some farmers may consider cutting back on or completely cutting out some inputs altogether. These decisions should be calculated, thought through completely, and be based on past experiences, not emotional. For example, use extreme caution when cutting back on inputs like fertilizers. Farmers need to ensure that the farm fertility is properly maintained to provide good yields and root structures that support healthy stands and reduce erosion. Cutting back too much on fertilizer inputs not only lessens
the chance of having a good yield year in the coming season, but also in future years. Weed management is becoming a larger driver for input costs as weed resistance to herbicides becoming more common. Developing a weed management plan and sticking to it for the entire farm may result in higher input costs, but it may also be in the best interest for long-term profitability. Crop rotation may also help reduce input costs by reducing some fertilizer and farm chemical costs as well as seed costs. Taking the time to set realistic yield goals based on calculated decisions and planning ahead can result in the maximum return on investment and profitably.
Sources:
1 Miller, A.G. 2000. Establishing realistic yield goals. Agronomy Pm-1268. University of Iowa Extension. https://store.extension.iastate.edu/product/Establishing-Realistic-Yield-Goals
2 Shober, A. and Taylor, R. 2015. Estimating yield goal for crops. University of Delaware Extension. https://www.udel.edu/academics/colleges/canr/cooperative-extension/fact-sheets/estimating-yield-goal-crops/
3 2015. It’s not just about costs per acre, even in tight times. Purdue University Extension. https://ag.purdue.edu/commercialag/home/resource/2015/04/its-not-just-about-costs-per-acre-even-in-tight-times/
Legal Statements
ALWAYS READ AND FOLLOW PESTICIDE LABEL DIRECTIONS. Performance may vary, from location to location and from year to year, as local growing, soil and weather conditions may vary. Growers should evaluate data from multiple locations and years whenever possible and should consider the impacts of these conditions on the grower’s fields.
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