Do’s and Don’ts for Spring Planting
“In farming, you only get one chance every year, so it’s worth it to do it right the first time.”
That statement is so very true. Below are a few things to keep in mind to optimize your corn and soybeans yields:
Soil Moisture. Working ground when it is too wet leads to slabbing and clodding of the soil, so areas within fields dry at different rates. A kernel of corn imbibes, or takes in, about 30% of its weight in water during germination. When kernels in a row are exposed to varying amounts of soil moisture, their germination rates and emergence will vary from plant to plant. The result is uneven emergence, poor early growth and potentially severe stand loss. Soybeans need more water at germination, taking in about 50% of seed weight on average. As with corn, good seed-to-soil contact is critical, so avoid cloddy conditions.
Soil Temperature. Corn germinates best when soil temperature is close to 50° F. Approximately 120 growing degree units (GDU’s) are required for corn to emerge. During periods of cool temperatures, it can take several days to achieve those GDU’s. Once a corn seed germinates, it can exist for about 14 days on the energy that is contained in the endosperm. Under ideal conditions, the seed will emerge and develop a root system in much less than 14 days. Most researchers agree that soybeans emerge best when the soil temp is 55° F or warmer. Avoid planting soybeans if the temperature is below 55° and a cold rain/weather event is expected within 24 hours after planting.
Planting depth: Soybeans respond best when planted at 1¼ to 1½ inches deep and should never be planted deeper than 2 inches! Remember, a soybean seedling must push that cotyledon through the soil as it emerges. The soybean seedling requires much more energy than a corn seedling with its narrow coleoptile (shoot). Target depth when planting corn is 1½ inches to 2¼ inches. Planting corn shallow is as bad as planting soybeans too deep because nodal roots will not develop properly and “Rootless Corn Syndrome” may result.
Soybean inoculant: Old-timers say if soybeans have been planted in a field within the past four to five years, then an inoculant is not necessary. However, recent studies and more advanced inoculant formulations show otherwise. Using inoculants in light, sandy soils, as well as weather-stressed (flood, drought, etc.) fields have shown increased plant health and improvements in overall yield. Consider running side-by-side trials on your farm to see if inoculants will work for you.
Problems like sidewall compaction, surface crusting, herbicide injury, seedling insects and seedling diseases can all lead to delayed plant and root development. These, and many others, can all cause uneven emergence and poor stands in corn and soybean. That’s why it’s important to control what you can to set up your crops for success!