by DLF Seeds (published with permission)
Every spring, producers weigh several decisions related to their operations – everything from marketing and budget considerations, to equipment and operating expenses. Farmers have a lot on their plate. Planning for spring forage plantings is necessary (some years more than others), but understandably it may not be foremost on their minds. For this reason, the team at DLF Pickseed has started a section in our newsletters titled Management 101 – full of reminders designed to help producers maximize success when headed to the field.
A subject that consistently gets mentioned is seeding depth. Soil variability and competition from other plants – desirable and undesirable – can place newly planted seeds in an uphill battle. It’s critical that growers do everything possible to achieve the proper planting depth, giving their latest investment an opportunity for success. Here are 5 key reminders to ensure proper seeding depth and maximum germination:
1) Understand that seeds of different size normally require a different depth of seeding. Most forage grasses and legumes are smaller seeded; thus they require a shallow depth between ¼” and ½”. However, forage sorghum and small grains need to be planted deeper. Teff, for example, establishes best when seeded at less than 1/8”. Traditionally, seeding depth should be approximately 3-5 times the diameter of the seeds being sown.
2) Soil texture will impact proper seeding depth (i.e. sandier soils will tolerate deeper seed placement). As a rule of thumb, the same orchardgrass planted at 3/8” on clay soils should be placed between ½” to 5/8” on sand. Emergence declines significantly if forage seeds are planted too deep. Seeds planted too shallow run the risk of not getting enough moisture. Grasses and legumes seeded closer to the surface require rainfall or irrigation post seeding.
3) When the plan calls for planting a mix of several species, find an appropriate seeding depth that will be most acceptable for the seed sizes in the mix. If this isn’t possible, then panting equipment with a separate seed box will be needed. Once again, moisture is key. If precipitation is expected, then one could “cheat” planting a mix with different seed sizes a little shallower. Conversely, small seeded species planted at depths needed by larger seeds will struggle to emerge.
4) In fields where unevenness is the norm, achieving a consistent seeding depth is a bit more challenging. Drill or planter set up is key. On no-till drills, planting depths are adjusted by the cutting depth of the rolling coulter in front of the drill. Normally, the coulter should cut or slice the soil twice as deep as the planned planting depth. On most drills, the disk openers and press wheels work in tandem to affect down pressure and proper seed depth. For growers using rented equipment, this step is even more important and demands more time and energy. Make sure all the rows are set up consistently across the tool bar.
5) When starting each spring, doing a test run first before setting out across a larger area safeguards against errors. Some folks even spray paint a little bit of seed to start (with a bright color), making it easier to locate and check depth. Adjustments may be necessary along the way to make up for changes in moisture or soil type.