It was already known earlier this spring that we were probably going to see around a 25 percent reduction in forage production this year due to the dry conditions that occurred last fall and if spring moisture remained below normal that there could be significant reductions in forage production for 2021.
While recent rains were very welcome and have improved the outlook for the time being, lack of moisture during April and much of May has likely already caused further impacts on the forage production potential for the year.
While recent rains may be too late to mitigate any reduction in perennial forage production, it has improved the prospect for annual forages or cover crops that could be used for supplement hay or grazing.
Annual forage options for hay that are “more” drought tolerant and cost effective would include forage barley or spring triticale, which can be planted from early May to early June and Siberian millet that can be seeded from late May to early July.
Forage oats would be another option although it is not as drought tolerant as forage barley and will tend to show higher nitrate levels sooner with stress. That’s not saying that nitrate toxicity can’t be a problem in other forage crops such as barley or triticale as they certainly can accumulate nitrates as well under extended stress conditions.
In terms of warm season grasses, the sorghum-sudan hybrids would be another option but they are not as drought tolerant as Siberian millet. Plus, they can be more difficult to cure for hay than the millets. Another of the foxtail millets, German millet, tends to be intermediate, not as drought tolerant as Siberian millet, but more drought tolerant than the sorghum-sudans.
While any of the above could be grazed as well as being put up for hay, a cover crop may be the best option if you are looking for something strictly to graze. Planting a mixture of cool and warm-season grasses, broadleaf crops and legume species will create diversity, help minimize risk due to weather conditions, extend the grazing period due to different growth stages, and increase soil health benefits.
The diversity created by the cover crop mix can help minimize risk due to weather as the different species included in the mix have different rooting structures and different times of peak moisture and nutrient uptake as compared to single species which are all competing for the same resources at the same time. Thus, multi-species often out-produce single species.
In a demonstration conducted in Burleigh County under dry condition back in 2006, 6 different cover crop species were seeded individually and then in a diverse mix containing all 6 of the species. In July, with only 1.8” of growing season precipitation, many of the individual species were showing obvious moisture stress while the diverse mix remained green and produced over twice as much biomass as any of the single species.
With these thoughts in mind, staff with the Williams County Soil Conservation District and Natural Resources Conservation Service have been collaborating since earlier this spring to see if we could come up with a cost effective cover crop mix for drier conditions.
One of the mixes we came up with includes forage barely and Siberian millet based on the above information. For a legume, we included field peas. Field pea may not be the best in terms of drought tolerance but they tend to be one of the more cost effective legumes. Cowpeas would be another option for a legume that is more drought tolerant than field peas but they also are generally more expensive and add to the cost. Also, included in the mix were collards and turnips. These Brassica species aren’t necessarily considered drought tolerant, but are very desirable in a cover crop mix due to their remarkable forage quality even after a killing frost. If we would get some moisture later in the season, the thought was these Brassicas may come on to provide some later season grazing. While designed primarily for grazing, we did try to keep inclusion rate for the Brassicas on the lower side so the cover crop could be potentially hayed as the Brassicas tend to be high in moisture and can be difficult to cure for a baled forage. Last, we included a small amount of sunflower as sunflower is a deep-rooted crop that tends to be fairly drought tolerant and is readily utilized by cattle.
The Soil Conservation District in conjunction with the Williston Research Extension Center does plan to seed a cover crop demonstration just south of the District’s Tree Shed on the Extension Center grounds. In addition to seeding the cover crop mix outlined above and a couple other variants of the mix, we also plan to seed individual species of some of the primary components in the mixes as a comparison. Watch for more information on the trial as the growing season progresses.