Our long-term goal is to support producers in the High Plains (and beyond) to adopt management strategies that are profitable and build soil and ecosystem health. Further information on this study and managing post-wheat-planted cover crops for livestock grazing can be found using the following link: webapp.agron.ksu.edu/agr_social/article_new/cover-crops-grown-post-wheat-for-forage-under-dryland-conditions-in-the-high-plains-400-4
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The post-wheat cover crops were planted mid-July to early September.
The field size varied from 59-133 acres. Fields were laid out with 4 large paddocks, 4 ungrazed exclusion areas, and an unplanted ‘fallow’ exclusion area. Cattle were grazed an average of 39 days. Each replicate was grazed for a little over a week. After termination in the early spring, post-wheat planted fields were planted with corn. |
2017 Post-Wheat Planted Cover Crop: 1# radish, 0.5# rapeseed, 4# cowpea, 6# Austrian winterpea, 4# sorghum sudangrass, 2# German millet, 3# sunflower, 20# triticale, 0.2# phacelia. Total: 41 lbs/acre, ~$23/acre
(excluding delivery)
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2018 Post-Wheat Planted Cover Crop: 1# radish, 0.5# rapeseed, 5# cowpea, 4# Austrian winterpea, 4# sorghum sudangrass, 2# German millet, 1# sunflower, 20# triticale, 0.2# phacelia, 0.75# sunn hemp. Total: 38.5 lbs/acre, ~$24/acre
(excluding delivery)
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The graphs above show the species composition of the forage biomass samples collected in 2017 and 2018. The 2017 cover crop mixture averaged 0.6 t/ac in the grazed and 0.9 t/ac in the ungrazed. The 2018 cover crop mixture averaged 0.3 t/ac in the grazed and 0.4 t/ac in the ungrazed.
Post-wheat cover crop grazing was slightly more challenging than spring planted cover crop grazing. In 2017, two out of 4 cover crop planted fields were unable to be grazed due to a dry fall weather that limited biomass production. The two successfully grazed fields were planted early enough to take advantage of moisture that came through before things dried out. The average stocking rate for cattle grazed in 2017 was 273 lbs/ac and the average daily gain was 0.5 lbs/day.
In 2018, only one of four cover crop planted fields were unable to be grazed due to excess snowpack/moisture on one of the fields and the potential for compaction. The average stocking rate for cattle grazed in 2018 was 354 lbs/ac and the average daily gain was 1.4 lbs/day.
In both years, there were fields that were grazed while still green and fields that were stockpiled and grazed dry. The cattle had to be removed from the field for at least a week on the fields that were grazed green due to the risk of prussic acid from the sorghum.
In 2018, only one of four cover crop planted fields were unable to be grazed due to excess snowpack/moisture on one of the fields and the potential for compaction. The average stocking rate for cattle grazed in 2018 was 354 lbs/ac and the average daily gain was 1.4 lbs/day.
In both years, there were fields that were grazed while still green and fields that were stockpiled and grazed dry. The cattle had to be removed from the field for at least a week on the fields that were grazed green due to the risk of prussic acid from the sorghum.
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Corn yield between the fallow and the grazed treatments were not different, but there was a yield reduction of ~6 bu/ac in the ungrazed treatment. Soil moisture at corn planting is often not a good predictor of corn yields and we did not see relationships between soil moisture at cover crop termination and corn yields. |
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