Planting conditions improve as soils dry out for crops

Ned Birkey

The MSU Enviroweather station at Applewood Orchards at Deerfield is reporting degree days for 2023, from March 1 to April 20 was 181 GDD (base 50º Fahrenheit), well above the 131 GDD of last year and the six-year average of 144.4 GDD. The minimum soil temperatures, as measured at the two-inch level, under bare soil ranged from 57.9º Fahrenheit on April 15 and coming down to 41.3º Fahrenheit on April 20. The high soil temperature reached 76.7ºF on Saturday, April 15, which is why all the forsythia was in bloom. The weather forecast for the rest of April was cooler than normal with scattered rains, but generally dry conditions. Currently the forecast for May is for more normal temperatures and likely below normal precipitation.Planting conditions improve as soils dry out for corn, soybeans, potatoes, some early sweet corn and other early season crops. The fact that “ultra-early” planting did not occur due to wet soils, does not mean that crop and yield prospects are adversely affected.Corn planting has begun and will continue into dry soils. Emerson Nafziger reminds farmers that planting depth should remain at one and a half to two inches deep. Planting too shallow can expose seeds to drying conditions before germination begins and can limit the uniform uptake of water by all the seeds. Deeper planting delays emergence, especially in heavy soils that also tend to crust. There is no advantage to planting from three inches deep if soil conditions are good, the risk is nearly all on the downside. Likewise, corn seeding rate depends upon the varietal characteristics and recommendations and uniformity of soils, but generally maximize profit at around 30,000 seeds per acre. Corn required about 100 to 120 GDD to emerge, which means that both air and soil temperatures have a large influence on corn emergence timing from the soil. Corn can emerge in warm soils in as little as four to five days or may take 20 to 30 days if soil temperatures are cool.Soybean planting also started though cooler soil temperatures will delay emergence until soils warm up to about 60º Fahrenheit as seed emergence can vary from six to 21 days depending upon soil temperature. With a cooler forecast, soybean planting can proceed as soils dry out without working soils too wet. Results from 14 years of the Michigan soybean yield contest found that the top ten yields came from soybeans planted as late as around mid-May. As important is a seeding rate of around 165,000 seeds per acre, depending upon the variety, seed treatment, soils and plant and row spacing. We know from field demonstrations going back to 1994 that fewer soybean plants will have more pods as long as plant spacing remains relatively uniform. This saves on seed cost without sacrificing yield.Insect trapping will be done by new MSU Vegetable Educator Chris Galbraith this year as he secures traps, lures and locations. He also plans to do some vegetable disease monitoring with selected crops and diseases. Anyone interested in getting updates should contact him at 734-240-3178. Some trapping will be done at the MCCC Student Ag Farm and other locations in southeast Michigan and northwest Ohio.Protecting the garden from frost is still a concern despite April 25 being the statistical 30-year average date of the last 32 º Fahrenheit frost date for Monroe County. There is still a chance of frost even at temperatures above 32º Fahrenheit and even after April 25 though the odds favor a statistical lower chance of cold. Fortunately, slower early season growth that keeps plants closer to the somewhat warmer soil line will aid in protecting young seedlings as the air temperature is measured at five feet above ground. Hardy vegetables can withstand freezing temperatures for short periods without injury and include broccoli, cabbage, collards, kale, mustard greens, onions, parsley, peas, radish and spinach. Frost tolerant vegetables can withstand a light frost and include beets, carrots, cauliflower, celery, lettuce and potatoes.