farmgate: These Five Points At Planting Mean High-Fives At Harvest.
It is late May. After a wet spring you have finally mudded in more than 1,500 acres of corn; some for yourself, some under a cropshare lease, and some for a custom farming client. As you clean up the planter to put it away, you notice a problem with one of the major settings. This is not a minor “Oooops!” This is a major “Oh _ _ _ _!”
Peter Thomison of Ohio State reminds us that mistakes during planting season are usually irreversible and the impact is probably a diminished yield potential. In the latest Crop Observation and Recommendation Network newsletter the OSU agronomist makes a number of checklist suggestions to ensure you avoid mistakes in getting your corn crop off to a good start.
1) Tillage. Thomison’s suggestion is to limit tillage to only the necessities and only when the soil conditions will cooperate. Secondary tillage should be limited to only preparation of an adequate seedbed, since it can create yield-reducing compaction. Fracturing compacted layers is sometimes necessary, but limit that activity to the fall.
2) Timetable. Know the optimum planting window for your region (probably sometime from mid April to mid May) and shoot for that target. Early planting in wet soil cut yields, just as late planting will. Thomison says, “If growers have the equipment capability to plant more than half of their corn acres prior to the optimum planting date, then this should allow planting all the corn acres prior to the calendar date when corn yields begin to decline quickly.” Typically the two to three weeks in the optimal planting period will contain one day out of three that fieldwork can reasonably progress. And Thomison says the calendar date is more reliable than soil temperature for planting decisions.
3) Seed depth. Corn seedlings like frost about as much as your spouse’s tomato plants. But you can’t cover up your corn with sheets and blankets. At this time of year when the soil is moist and the evaporative rate is low, planting depth should be no more than 1.5 inches. Later on, when the soil is more dry, push the seed down to the moisture, but no more than 2 inches deep. Care should be taken to ensure the seed is not so shallow that nodal roots will not properly form and that the seedling does not suffer from a soil-applied herbicide. The impact of irregular planting depths will be obvious when corn is sold next fall.
4) Seeding rate. What will your population be this year? 28,000? 35,000? 42,000? Higher rates should be reserved for fields with high yield potential, as determined by fertility and water holding capacity. Cutting the seeding rate to save on seed cost typically reduces revenue more than cost is saved. If planting into cold soil, some seeds will not properly germinate, so boost the seeding rate above the desired population.
5) Calculate your expected population. Thomison says unless you have a good stand of volunteer corn, your population will probably be less than your seeding rate. That is the target germination rate for seed corn, and the final population is determined by planting date, tillage practices, pest problems, chemical injury, planter performance, and seed quality. With those reducing the final population up to 15%, consider a seeding rate 10-15% above the desired population.
Summary:
Mistakes at planting time will be reflected in lower yields at harvest, so develop a checklist to ensure you have made every effort to achieve maximum yields. That includes soil conditions, planting date, planting depth, seeding rate calculations and seeding rate flexibility per field. Your seed corn needs a good start in life, and the care that is given in the next few weeks will pay off on the settlement sheet.
Posted by Stu Ellis on April 10, 2008 12:28 AM to farmgate