Wheat Drill Calibration Tables

Chad Lee, Extension Agronomist, University of Kentucky

As producers gear up for wheat planting, calibration of the seeder is extremely important. Below are two tables to use as quick references in the calibration process. Most producers are using drills with 7.5-inch row spacing. The first table calculates how much seed to collect in 50 linear feet from one row of the drill. Target populations of 30 and 35 seeds per square foot are used for the calculations. The needed seed weights are listed as ounces (oz.) and as grams.

Maximize Wheat Yield Potential Despite Late Planting Dates

Carrie Knott, Extension Agronomist-Princeton, University of Kentucky

For most areas in Kentucky, this spring and summer has been unseasonably wet and cool. Since April rainfall across Kentucky has been almost 6 inches above normal and the daily high temperatures have been almost two degrees Fahrenheit cooler than normal. These unseasonably wet and cool spring and summer conditions delayed corn planting. This year on May 19 only 56% of the corn was planted as compared to 75% for the five-year average. This will likely delay corn harvest. As of September 1 only 1% of corn was harvested as compared to 12% for the five-year average. Wheat producers need to be prepared for delayed plantings this year due to delayed corn planting, development and harvest.

Fall 2011 Wheat Planting Decision

Greg Halich, Extension Economist, University of Kentucky     

(Edited 10/04/11)

Kentucky grain farmers in some parts of the state have been harvesting corn for a few weeks now and they will soon need to decide how much wheat to plant this fall.  In Kentucky, wheat is almost always planted in the fall following harvest on corn ground, and then double-cropped with soybeans in early summer after the wheat harvest.  This allows for two crops in one year.  However, soybeans planted after the wheat harvest are more susceptible to summer drought, so on average, yields are lower for these double-cropped soybeans.  In Kentucky, this yield reduction typically averages around 20%, but in many years there will be no yield difference due to weather.

Wheat Planting: Two Options and Neither is Great

Chad Lee and Jim Herbek, University of Kentucky

Getting wheat into the ground right now is a real challenge because of the dry, hard soils. Since many producers have locked in high market prices for next summer, we are assuming that all producers reading this fully intend to plant wheat. So, in the discussion that follows, we are removing the option of “not planting wheat”. With this in mind, producers have two options for planting wheat: 1) plant now and hope for rain, or 2) wait for rain and then plant. Both options have their risks.

Option 1. Plant now, and hope for rain

Positives: You get the wheat planted, perhaps a little early, but it is in the ground. Getting seed at the proper depth will be a challenge (see action item below).

Risk 1: Hessian fly. The recommended first dates to plant wheat in Kentucky are October 10 in northern Kentucky and October 15 in southern Kentucky. These dates are based on historical Hessian fly free dates and also coincide with first fall frosts. These dates are earlier than the first frost, recognizing that wheat germination is normally several days after seeding.  The soil is so dry right now that any wheat planted is not going to germinate until we get rain. So, the risk of planting a few days early is minimized some this year because of the lack of soil moisture.

Risk 2: Just a little rain. The wheat will not germinate until we get rain. One of the worst things that can happen is to get a little rain (maybe half an inch), which is enough to let the seeds germinate but not enough for the young seedlings to survive without additional precipitation.

Risk 3. Varmints. The longer seed stays in the ground before germination, the greater chance there is for mice, voles, etc. to dig up and eat seeds.

Risk 4. Soil Erosion. Seeding now may require some tillage to allow the grain drill to get through the soil surface (see Action Items below). If you do tillage, you increase the chances for soil erosion from wind and water. If you have fields that are rolling and you use tillage on those fields, a heavy rain could do severe damage to your fields.

Action Items.

1. If you decide to plant now and hope for rain, get the seed about 1- to 1.5-inches deep. In a year like this, there is no “seeding to moisture” unless you plan to use a backhoe in place of a grain drill. With soils that are very hard, you may need to run a disk over the field to break up the soil and allow a drill to get through. If you decide to do this, then try to do as little tillage as possible while breaking up the soil. Set your disk blades to run straight so the implement is not throwing dirt into the air, but simply slicing through the soil.

2. Calibrate the drill so that you are delivering the correct rate of seed. Perhaps increase your seeding rate a little since you have some slightly higher risks of seed loss.

3. Monitor fields once the rains come to determine the quality of your stands.

Option 2. Wait for Rain and Then Plant

Positives:  By waiting for rains, the soils will be softer, getting proper seed depth is easier, and tillage is not necessary. 

Risk 1. Later planting date. If you wait for rain, it could rain and rain and rain. This could push back the planting date, leaving you to scramble to get wheat planted. The later planting dates could result in lower yields, as research indicates.

Risk 2. Soil Compaction. This sounds crazy given the current soil condition, but if it rains a lot, you could find yourself trying to plant into wet conditions, which can lead to soil compaction.

Action Items

1. Calibrate your drill with all seed lots. Since you are not going to plant right away, you might as well make sure that your equipment and seed are ready to go as soon as possible. Once the rain comes and the soils soften, you don’t want to waste a day getting machinery ready. Do it now, while you have the time.

2. As soon as the rains come, get to the field and get the wheat planted. Since many fields have several soils types, you may have areas of a field with more soil moisture than others… or different fields with different moistures. You will want to double-check seeding depth when entering new fields and you may want to check it when entering different soil types in the same field.

3. Put blinders on and develop nerves of steel. The blinders are to prevent you from seeing your neighbors trying to plant wheat before the rains. The nerves of steel are needed when the blinders don’t work. 

Wheat planting when futures are high and seed might be short

Chad Lee and Jim Herbek, University of Kentucky

Many producers locked in wheat contracts for 2011 at or over $7 per bushel and some are growing wheat for the first time in five years. There are rumors that seed supply is tight. If these rumors are accurate, there may be some temptation to skimp on seeding rates in order to cover more acres.  If you are one of those producers, just know what your risks are by cutting back and proceed with caution.

Maximum wheat yields normally require a final stand of 30 to 35 plants per square feet, but under the right conditions, stands as low as 20 plants per square foot will yield well. Getting a successful stand requires several things, including timely seeding, an accurate seeding rate, correct seed depth (1.0 to 1.5 inches), adequate soil moisture, and no seedling diseases.

Wheat should be planted from about October 10 to October 30 for most of Kentucky. This window is normally provides the best opportunity for getting a good stand and good growth before the cold winter months. Seed rates can be 30 to 35 seeds per square feet, but if you are considering dropping back a little, this is the time to try it. If planting occurs after October 30, then the seed rate should be 35 to 40 seeds per square foot. These seed rates assume a standard germination of 90%. For seed lots with lower standard germinations, a higher seeding rate is needed.

Drill calibration is absolutely necessary to dropping the correct amount of seeds. This process takes time and should be conducted with each seed lot you receive. If you do not have the time and/or patience for this procedure, then hire someone to calibrate your drill. This procedure will benefit your wheat production system.  Guidelines on calibrating wheat drills is available in the ID:125 Comprehensive Guide to Wheat Management, Chapter 4 “Planting and Drill Calibration” http://www.uky.edu/Ag/GrainCrops/ID125Section4.html.

Adjusting the drill for planting depth also takes time but will result in better stands. These adjustments need to be made in the field on the day of planting. Field conditions change from day to day and the pressure needed to get the desired depth may change day to day as well.

So, if you decide you are short on wheat and you want to skimp on seed, be sure you know the conditions in which you are planting. If possible, try to skimp in situations that will still provide a chance for good stand establishment. In a year when a large part of the 2011 crop may already be sold, skimping on seeding rates should only be used as a last resort.