A Report from Polk Soil and Water Conservation District
As the planting season begins on the fields of Polk County, Iowa, the farmers have been reflecting on their fall Cover Crop planting decision. The staff of the Polk SWCD have been hard at work gathering their insights. The conversations reveal valuable lessons about cover crop performance during a very dry fall cover crop planting season and the importance of timing and method in their establishment.
Oats
While some farmers initially considered planting a cover crop of oats in late August and early September, the unforgiving combination of heat and dry weather dissuaded them from their plans. Ultimately, many opted to not plant a cover crop at all rather than to sow seeds in conditions unfavorable for germination.
Winter Rye
With the continued dry conditions in late September and October, farmers who opted for broadcast seeding either with a highboy seeder or other equipment encountered hurdles. On some farms, the seeds initially had enough moisture to swell and begin to germinate, but they eventually succumbed to heat and moisture stress. Other farmers noticed an uneven stand and they attributed that to uneven germination due to low moisture. The results were mixed. Some farmers had sporadic stands. “It just looked terrible, very patchy” one farmer lamented. Others were happy with their investment. At least one farmer agreed that they would have drilled the Rye rather than broadcast it if they got the chance to redo planting in 2023.
Conversely, farms where cover crops were drilled demonstrated resilience in the face of the dry spell. These fields boasted good germination rates and uniform stands, showcasing the effectiveness of drilling in ensuring seed-to-soil contact and moisture retention. Notably, one farmer who drilled two bushels per acre of winter rye reported a dense and robust stand, regretting only that he had delayed planting one of his fields after harvest. “We just did not have the time to plant the cover crops immediately after harvest”. The difference in stand height between fields where rye was promptly planted and those with a ten-day delay was described as “amazing,” underscoring the significance of timely planting in maximizing cover crop potential.
One farmer who did not own a drill or a vertical till equipment opted to chisel plow the rye after it had been “floated” on along with the dry fertilizer. “I wasn’t sure it would work, but I knew it had to be covered to get good germination”. “The Rye look great this spring”, he said. He eventually calculated that that cover crop had produced the equivalent of 20 bales of hay to feed his cattle. He remarked “I’m definitely doing that again next year if I get the chance”. Another farmer used his cover crop this year to capitalize on his livestock investment. Drilling rye in the fall and fertilizing in the spring will provide forage for his cows, and potentially letting him bale the rye for summer forage.
All the farmers in this study were aware of the benefits of planting cover crops, including erosion control to soil health, however, most farmers are still working out the fine details of how to take full advantage of the cover crops, and timing management decisions. The insights gleaned from the experiences of Polk County farmers underscore the importance of adaptive management practices in navigating unpredictable weather patterns. Normal Fall weather provides adequate moisture to establish cover crops that have been broadcast. On the other hand, establishment can be sporadic under very dry Fall conditions. However, even in a very dry year, cover crops will germinate and produce a uniform stand when they get good seed-to-soil contact and good moisture retention. Crops that are drilled, vertical tilled or even chisel plowed will retain enough moisture in a dry year to establish a strong stand. Timing is everything to getting a successful cover crop that will work for you.
Cover Crop Demonstration Plot
The Polk SWCD staff asked farmers one final question “what they would like to see planted in the 5-acre Polk County Cover Crop Demonstration Plot”. A fair number of Farmers requested “something other than Rye that will give us lots of biomass ahead of corn”. Others asked to see unique mixes of winter-kill species and alternative grass species. Many wanted to know more about timing of planting in the fall and maximizing If you have a suggestion for what you would like us to plant, let us know. You can contact me at: Michael.james@ia.nacdnet.net or call me at 515-776-4241 x3.
Like this:
Like Loading...
