- Agronomic: barley, canola, corn, flax, millet, oats, rapeseed, rye, safflower, sorghum (milo), soybeans, sunflower, wheat
- Vegetables: peas (culinary), turnips
- Animals: bovine
- Animal Production: grazing - multispecies
- Crop Production: crop rotation, cover crops, nutrient cycling
- Education and Training: demonstration, extension, farmer to farmer
- Farm Business Management: budgets/cost and returns
- Natural Resources/Environment: biodiversity
- Production Systems: agroecosystems
- Soil Management: organic matter, soil analysis, soil quality/health
The 2014-2016 project sought to measure water usage, soil health indicators and weight gain of cattle in cash crops that were drilled with cocktail cover crops (CCs) v. plots without CCs. The impact of CCs upon each of these aspects was explored. The three, participating producers from southwest IA and southeast NE were impacted by 45” of historical rains in 2015 and 37″ in 2016. The role of historical rains cannot be overstated thus their impact on proposed goals and objectives is addressed accordingly. The results are presented in a manner so that limitations are clearly evident and stated.
The project met many goals while others were partially attained or not feasible primarily because of the weather.
The project did identify weight gain in cattle, slight increase in soil health and mitigate soil loss through the stable base of cover crops during intense rains. The project was inconclusive on cash crop yield gains and water usage. These aspects will be discussed in the “outcomes and impacts” section.
The project was originally conceived and initially focused on three producers' farms: one in southwest, IA; two in southeast, NE. The involvement of producers from similar and comparable geographic areas was purposeful yet the historic and concentrated rains of 2015 and 2016 impacted the ability of each producer to complete their respective project. Second, it made it difficult to truly gauge the relationship and/or the cause/effect of cover crops and moisture usage.
First, the late- and wet springs, (2015 and 2016) impacted crop rotation thus in turn the viability of various cover crops (i.e., radishes, turnips having time to grow and then be grazed in the fall before the early frost).
Second, the harvests were late because the weather did not allow crops to appropriately "dry down" in the fields in order to be at the appropriate moisture level (i.e., 14% in McDonald's non-GMO soybeans). Harvest generally went to the mid- to late-part of November in 2015 which prevented drilling in most cases and in turn reduced cover crop options.
Third, the lack of cover crop growth impacted whether cattle could graze on plots and the biomass. This forced different mixtures of CC uses and impacted the grazing "window" and in turn the ability to positively impact weight gain. The lack of biomass impacted the ability to create carbon and in turn soil health but the health was positively impacted, overall.
Fourth, the timing and types of water sensor moistures were changed. Because of #1-3 and the sudden onset of extreme cold in late October/November, sensors had to be augmented with informal moisture checks and satellite records. It prevented reliable and valid data.
The following article provides partial credence for the project's goals and overall purpose. Ray Archulets assisted Ackley and McDonald through informal advice and modeling. This is a part of our longterm goal--to replicate nature and the prairie.
http://johndeerefurrow.com/2016/06/03/building-soil-livestock/ [See excerpt below.]
"A place for livestock. Cover crops help soils by feeding microbes during the winter and adding organic matter, but they have yet another benefit: they bring in livestock says NRCS soil scientist Ray Archuleta. Anyone with an interest in soil health will undoubtedly have heard of Archuleta. He’ll freely profess that, after many years of working with NRCS, he had a major shift in thinking a few years ago. 'I finally had the epiphany that nature was always the mentor. It was always the template, but my education got in the way,' says Archuleta. 'I came to realize I was the product of reduction science, not holistic science.'
"Attend one of his workshops and you’ll hear him use the words biology and ecology and microbes. But another one is 'biomimicry.' In short: Nature already has the answers. What farmers need to do is let nature work for them. In the case of livestock, look at the buffalo and the wildebeest, he says. They move in groups, and the urine and manure distribution is closer. When farmers let livestock mob graze their pastures, they are mimicking that aspect of nature. Farmers will see huge spikes in bacteria, better nutrient cycling, and increased organic matter. In addition, the cover crops themselves change. When a plant is being grazed, says Archuleta, it reallocates some photosynthate materials back into the root system and stimulates more root growth. Plus, grazing causes the roots to release compounds that feed soil biology and stimulates the roots. 'Roots start dying and growing and dying and growing, and bacteria feeds on those roots. That becomes part of nutrient cycling.'”
The project had several objectives and performance targets. We tried to focus on measurable steps while noting anecdotal evidence if pertinent. We wanted to be sure that the work informed future producers.
- Soil properties testing including water infiltration, soil density and soil organic matter levels were completed for two producers.
- Determine water usage (*note this was not informative because of the excessive rain and subsequent impact on cover crop growth, cash crop water usage and weight gain in cattle).
- Complete the Haney Healthy Soil Test, Basic Soil Test, PLFA (phospholipid fatty acids) tests and assess biomass were completed on the majority of fields.
- Complete an economic analysis (partially completed because of the delays in planting and excessive rains; anecdotal findings were determined).
- Determine the weight gain of cattle in CC v. grazing in cash crop stubble (general results as based upon harvest dates and CC seeding).
- Apply statistics to analyze the interplay between water usage, CC, livestock gains and cash crop yields (this was not possible nor reliable because of the aforementioned).