Final report for LNC18-412
Project Information
The Northern Great Plains (NGPs) is an area where cover crop establishment can be risky due to short growing seasons and/or limited water. With the short growing season also comes increased land-use competition between crop and livestock enterprises. This study aims to study cover crop and livestock integration in a comprehensive manner so that thorough economic, soil health, and livestock performance variables can be measured during the process of adopting cover crop grazing. The project enlists experts in each topic area to ensure the project is conducted appropriately for each discipline represented. The project will accelerate the outreach of cover crop and livestock integration through the use of cafe talks, workshops, with a farmer-focus. Demonstrations are simultaneously occurring on-farm to test the adoptability of cover crop grazing on a commercial scale.
Thus far the project is proceeding to accomplish the original scope, however it will take more time than initially believed. The Covid-19 pandemic greatly reduced the ability to conduct outreach in 2020. The plan is to proceed with tours and workshops in 2021. The research objectives will also still be achieved with the new timeline.
1). Evaluate an integrated crop/livestock management strategy of backgrounding weaned calves under a double or relay-cropping system by grazing cover crop and crop residues after cash crop harvest.
2). Evaluate the effect of cover crops and grazing livestock on soil health under a no-till system.
3). Conduct an economic analysis to evaluate the financial impacts of an integrated crop/livestock system in the NGPs.
4). Create public awareness about integrated crop/livestock systems in the NGPs across the state by establishing demonstrations sites and performing outreach.
Traditional backgrounding systems in the NGPs involve feeding harvested forages, co-products, and grains in a drylot setting for two to six months post weaning. Grazing cover crops is key for developing a low-cost system for wintering cattle by eliminating harvest and lowering yardage costs. Incorporating cover crops into existing crop rotations in the NGPs will improve the quality and quantity of available biomass for weaned calves. Undertaking this study will provide new information regarding the profitability of backgrounding calves in the NGPs and provide farmers with an opportunity to maximize profits and reduce the cost of their operations. Recent cow-calf return estimates from USDA's Economic Research Service showed high costs of production across the nation coupled with lower calf revenue. If these trends hold true, a number of farm families across the NGPs will be negatively affected. The key to sustainability in cow/calf operations will be to increase revenue and decrease expenses. Grazing cover crops in double or relay cropping systems is an efficient method for farmers to decrease feed costs when backgrounding weaned calves in the NGPs, which may lead to an increase in farmers’ net revenue (McCartney et al., 2008; Kumar et al., 2012).
The benefits of cover crops in improving cropping systems and agricultural sustainability are well documented and include increased soil organic matter and nitrogen, reduced soil erosion, increased nutrient cycling, improved soil structural properties, weed suppression, increased soil productivity and increased cash crops yield (Sarrantonio and Gallandt, 2003; Ghosh et al., 2006; Wortman et al., 2012; Blanco-Canqui et al., 2012; Bich, 2013). Despite the numerous benefits of incorporating cover crops into the cropping systems, adoption remains limited due largely to 1) the time commitment to plant cover crops at critical times of the growing season, 2) farmers’ concerns on the lack of short-term economic returns, but also 3) a lack of research studies on the benefits of cover crops in a cover crop/livestock integrated system in North Dakota. This study will address the third item, which in turn can help to address the second one. One short-term economic benefit is integrating livestock into the cropping system and increasing forage biomass at a time when forages in native pastures have declined in quality (Liebig et al., 2015). Additionally, cash crops will benefit from added nutrients from livestock manure which can also help improve soil health. Loss of soil organic carbon (SOC) from intensive annual cropping can negatively impact soil health and increase farmers’ reliance on commercial inorganic fertilizers to sustain crop productivity. Utilizing cover crops could benefit the cash cropping system by increasing soil organic matter, biological activity, greater retention and recycling of nutrients, and reduced erosion. Incorporation of cover crops like winter rye, clover, brassicas, etc. can also help reduce the need for synthetic fertilizer use over time.
Due to the short growing season in the NGPs, an interseeding or double cropping approach can be a workable option for incorporating cover crops into the existing cropping systems (Moore and Karlen, 2013). Seeding rye prior to soybeans has become a more acceptable approach recently, partly due to research conducted at NDSU and other universities in the Great Plains (De Bruin et al., 2005; Kaspar and Singer 2007). Primary goals for that system generally include management of glyphosate-resistant weeds and preventing soil erosion during the soybean crop years. The adoption of that system by area farmers has opened the door to interest in similar systems for corn production, including interseeding rye, hairy vetch, brassicas, and others. However, small grain production still represents the biggest opportunity to utilize cover crops in the NGPs. Both research results (Cicek et al., 2014; Samarappuli et al., 2014; Jones et al., 2015) and anecdotal evidence (i.e. less soil erosion reported by farmers with living cover crops) support the use of fall cover crops following spring wheat and are demonstrated options that can positively affect subsequent crops and soil health. Many of these options would also further support integrated crop/livestock systems.
Moisture competition can be an issue for some cash and cover crop combinations. Since double cropping is perhaps the only option to use cover crops in corn in the NGP, crop competition must be considered. Cover crops in this study will be seeded mid-season in the corn to balance the ability to grow sufficient biomass for grazing while not competing with corn at the early growth stages. Grazing in a corn/CC system has been understudied in North Dakota, but unpublished research from the NDSU-Central Grasslands Research Extension Center indicate that cover crops seeded into corn were producing yields of ~1000 lb/a (rapeseed, winter peas, triticale, oats). These values could be increased by using high biomass crops like hairy vetch and winter rye which also grow very late into the fall. Using a planter, rather than broadcasting seed, is also likely to also increase establishment. Research at the NDSU-Carrington Research Extension Center has measured up to 2 tons/a of corn residue after corn harvest. Assuming a conservative 25% utilization of the corn, and 13.75 lb/day DM intake per cow, the area used for this study should be sufficient in size.
Growing cover crops for fall grazing is viewed as a challenge in the NGP, since dry conditions and few frost free days limit cover crop species options and planting window, which can limit the amount of forage available for grazing in the fall. The perception of cattle-related compaction is also an obstacle for incorporating grazing on cropland. Through on-farm demonstration and farmer-driven implementation, this project will provide evidence that with proper management, crop production and fall grazing can be achieved in a synergistic way, on the same field, during the same growing season, with positive results to both components of the system. This research topic was initiated based on producer feedback from the Carrington Research Extension Center advisory board. Through inquiry, we found that both crop and livestock producers are interested in this synergy, particularly if economic and/or soil health benefits could be demonstrated. This systems approach is consistent with SARE’s mission and core ideologies, as research is still lacking on utilizing double or relay-cropping strategies to add lower-cost weight on weaned calves in the NGPs.
References
Bich, A.D. 2013. Impact of spring-interseeded cover crops on late-emerging weed suppression and ground cover in corn (Zea mays). M.S. thesis. South Dakota State Univ., Brookings.
Blanco-Canqui, H., Claassen, M.M., Presley, D.R. 2012. Summer cover crops fix nitrogen, increase crop yield and improve soil–crop relationships. Agronomy Journal. 104, 137-147.
De Bruin, J.L., Porter, P.M., Jordan, N.R. 2005. Use of a rye cover crop following corn in rotation with soybean in the Upper Midwest. Agronomy Journal. 97, 587-598.
Cicek, H., Entz, M.H., Thiessen Martens, J.R., Bullock, P.R. 2014. Productivity and nitrogen benefits of late-season legume cover crops in organic wheat production. Canadian Journal of Plant Science. 94, 771-783.
Faé, G.S., Sulc, R.M., Barker, D.J., Dick, R.P., Eastridge, M.L., Lorenz, N. 2009. Integrating winter annual forages into a no-till corn silage system. Agronomy Journal. 101, 1286-1296.
Ghosh, P.K., Manna, M.C., Bandyopadhyay, K.K., Ajay, Tripathi, A.K., Wanjari, R.H., Hati, K.M., Misra, A.K., Acharya, C.L., Subba Rao, A. 2006. Interspecific interaction and nutrient use in soybean/sorghum intercropping system. Agronomy Journal. 98, 1097-1108.
Jones, C., Miller, P., Burgess, M., Tallman, S., Housman, M., O’Dea, J., Bekkerman, A., Zabinski, C. 2015. Cover cropping in the semi-arid west: effects of termination timing, species, and mixtures of nitrogen uptake, yield, soil quality, and economic return. Proceedings from Western Nutrient Management Conference. Reno, NV. 2015.
Kaspar, T., Singer, J. 2007. Rye cover crops in a corn silage-soybean rotation. Abstract from American Society of Agronomy annual meeting. New Orleans, LA.
Kumar, R., Lardner, H.A., McKinnon, J.J., Christensen, D.A., Damiran, D., Larson, K. 2012. Comparison of alternative backgrounding systems on beef calf performance, feedlot finishing performance, carcass traits, and system cost of gain. The Professional Animal Scientist. 28, 541-551.
Liebig, M.A., Hendrickson, J.R., Archer, D.W., Schmer, M.A., Nichols, K.A., Tanaka, D.L. 2015. Short-term soil responses to late-seeded cover crops in a semiarid environment. Agronomy Journal. 107, 2011-2019.
McCartney, D., Fraser, J., Ohama, A. 2008. Annual cool season crops for grazing by beef cattle. A Canadian Review. Canadian Journal of Animal Science. 88, 517-533.
Moore, K.J, Karlen, D.L. 2013. Double cropping opportunities for biomass crops in the
north central USA. Biofuels. 4, 605–615.
Samarappuli, D.P., Johnson, B.L., Kandel, H., Berti, M.T. 2014. Biomass yield and nitrogen content of annual energy/forage crops preceded by cover crops. Field Crops Research. 167, 31-39.
Sarrantonio, M., Gallandt, E. 2003. The role of cover crops in North American cropping systems. Journal of Crop Production. 8, 53-74.
Sollins, P., Glassman, C., Paul, E.A., Swanston, C.; Lajtha, K., Heil, J.W., Elliott, E.T. 1999. Soil carbon and nitrogen: Pools and fractions, in: Robertson, G.P.; Coleman, D.C.; Bledsoe, C.S. (Ed.), Standard Soil Methods for Long-Term Ecological Research. 433 Oxford University Press, Inc., pp. 89–105.
Tonitto, C., M.B. David, and L.E. Drinkwater. 2006. Replacing bare fallows with cover crops in fertilizer intensive cropping systems: a meta-analysis of crop yield and N dynamics. Agriculture, Ecosystems, and Environment. 112:58-72.
Wamono, A., D.D. Steel, Z. Lin, T. Desutter, X. Jia, and D. Clay. 2016. Gypsum lowers drawbar power in Northern Great Plains subsurface drained sodic soils. Trans. ASABE. 59:1661-1669.
Wortman, S.E., Francis, C.A., Lindquist, J.L. 2012. Cover crop mixtures for the Western Corn Belt: Opportunities for increased productivity and stability. Agronomy Journal. 104, 699-705.
Cooperators
Research
Integrating animal agriculture into cropping systems will have varied impacts on an operation with measurable differences in a) soil biological activity, b) economic efficiency, and c) animal performance.
A cover crop/grazing study, under a no-till cropping system, will begin in the 2019 growing season and continue through the 2020 season. The objectives of the crop rotation study include 1) determine the impacts of cover crops and grazing treatment combinations on the current and subsequent rotation crop; 2) measure cover crop biomass production on grazed and no-grazed treatments; 3) measure soil health indicators on grazed and non-grazed treatments, and between treatments with and without cover crops. The trial will consist of a crop rotation experiment that includes combinations of cash crops, cover crops, and grazing treatments. The main plot (490 ft x 300 ft) will be cash crop, which will be either corn or wheat, and replicated three times across the experimental area. Each main plot will be split into three subplots. The subplots will consist of a positive control (45 ft x 300 ft), negative control (45 ft x 300 ft), and the grazing treatment (400 ft x 300 ft). The positive control will be a cash crop paired with cover crops but no grazing, representing maximum cover crop biomass production. The negative control will be a cash crop with no cover crop or grazing. The grazing treatment will consist of fall grazing of cash crop residues and cover crops. Table 1 shows the cover cropping system being evaluated with each cash crop.
Table 1. Description of stage of planting and cover crop mixes following each cash crop.
|
Cash Crop |
Cover Crop |
Time of Cover Crop Planting |
|
Wheat |
Peas/Radish/Turnip |
After wheat harvest |
|
Corn |
Rye/Turnip/Radish/Barley |
Corn V5-V6 |
In each year of the study cash crop yield and quality will be measured. Cover crop yield will also be measured in plots seeded to cover crops. Each subplot will be split in four equal areas (1100 sq ft each) to measure yield and other agronomic parameters on equal areas. The trial will be established as a randomized complete block with a split-plot arrangement.
After cash crop harvest, spring-born steer calves will be allowed to graze the crop residues and cover crops in late fall. The grazing period will be determined by availability of sufficient biomass to maintain positive weight gains. Prior to grazing, available biomass will be determined in each plot by clipping all the forage within a 1 m2 quadrat. Forty-five spring-born steer calves will be stratified by body weight and assigned to the following treatments: 1) wheat plot grazing, 2) corn plot grazing, 3) drylot backgrounding. Calves will be backgrounded over a period of 84 days. There will be 3 replicates (plots or pens) per treatment with 5 calves assigned to each replicate. Calves in the drylot will be fed a high forage diet for the duration of the study. Because of the limited area for grazing, steers from treatments 1 and 2 will be transferred to the drylot and will receive same diet as treatment 3 once the grazing period is ended. Calves will be weighed on days 0, 28, 56 and 84.
All the calves will be subjected to ultrasound measurement to estimate marbling score, ribeye area and fat depth at the beginning and the end of the study. Estimation of animal muscle and fat composition change between the start and end of the grazing period will be determined with an Aloka SSD-550V ultrasound machine equipped with a 3.5 MHz-17 cm transducer. Estimates will include longissimus-dorsi muscle area, fat depth, and percent intramuscular fat for marbling score determination. Composite forage samples will be collected from each plot and analyzed for chemical composition – dry matter (DM), crude protein, ash, neutral detergent fiber, acid detergent fiber, acid detergent lignin, cellulose, hemicellulose, and non-structural carbohydrates. Data generated will be subjected to analysis of variance using the Proc Mixed procedure of SAS (Version 9.4) in a randomized complete block design with a split-plot arrangement, with probability value (p-value) of 0.05.
Soil health will be assessed on soil samples (0-6 inches) collected before and after the implementation of the treatments, and it will based on the determination of biological, chemical and physical soil attributes that are more likely to be affected by the treatments. Biological indicators to be evaluated include SOM, and the physical fraction of soil carbon – particulate organic matter carbon (POM). Soil OM will be determined by loss on ignition at 360oC, and POM of size ranging from 53-2000 µm by the procedure of Sollins et al. (1999). POM will consist of permanganate oxidizable carbon (POC), from short-term soil incubation (Nelson and Sommers 1996). Phospholipids fatty acid (PLFA) analysis will be conducted as it provides a snapshot representation of living soil microbial biomass, community structure and abundance as affected by cover crops and livestock activity. Chemical indicators will consist of macro nutrients such as soil nitrate nitrogen (N) and phosphates (P), micronutrients (Zn, Fe, and Mn), soil pH, soil electrical conductivity, and soil cation exchange capacity.
A Magnum series Case-IH tractor with a dynamometer will be used to pull a no-till seeder across the experimental plots each spring. The tractor will be equipped with an AFS Pro 700 monitor and RTK-GPS to collect and map tractor performance data including fuel consumption, engine load, and fuel efficiency. The tractor speed and seeding depth will be held constant throughout all plots. Fuel efficiency (acres/gallon) will be used to indicate soil strength and compaction (physical properties). Data from the AFS Pro 700 will be exported to ArcGIS software for data point analysis and to create a soil compaction map of the experimental units.
An economic analysis of interseeding cover crops into 3-crop rotation will be carried out to evaluate their effects on the cash crops. Additionally, an economic analysis of backgrounding calves on the cover crops as well as in the drylot will be done to compare the costs and profitability of each type of backgrounding to let us know if it is financially feasible to background the calves on cover crops versus in a traditional drylot situation. In order to achieve this, records of all direct costs for the cover crop grazing as well as for the feedlot backgrounding will be recorded. The beginning and ending weights of the calves will be used to put a per pound value on them so as to measure how much income would come from each backgrounding method. List of records to be kept include costs for drylot, cost of production of feeds, or costs of feeds purchased, custom hire for any processing of feeds such as hay grinding. Costs for cash and cover crops – cost of seed, cost of fertilizer, cost of chemicals, custom cost to plant, cost of fencing, etc. Cost to be recorded for overheads for both enterprises are fuel, land cost, building depreciation, machinery depreciation, utilities, vet, supplies, marketing, etc. Labor will be recorded for each enterprise and specifically charged. Incomes – calf weights at weaning and calf weights at end of study. Prices will be recorded at each of those points to put a value on the calves. Any death loss will be recorded as well. From the economic analysis, we plan to provide information and a guide that farmers can use to integrate cover crops into their operations. This guide will help crop farmers estimate how much they can charge a livestock farmer neighbor to graze the field. In order to arrive at a fair estimate, we will factor in an adjustment for manure credit for grazing livestock and compaction if needed.
In the fall of 2019 there was a large snow storm in October that buried the corn research plots. This prevented any grazing from occurring as much of the snow remained until spring. The small grains plots were still able to be grazed that year. All plots were successfully established and grazed in 2020. The cover crop growth was greater in 2019. A drought in 2020 reduced cover crop growth. This limited the grazing days in the small grains system. Due to availability of both cover crop and corn residue, there was much more opportunity for grazing in the corn system even with the dry conditions.
Soil penotrometer readings were taken throughout each of the plots each year in the fall and spring. The readings were georeferenced in relation to the water tanks. The goal was to look for areas of compaction caused by cattle grazing. There were no compaction zone detected in any cropping system treatment nor year.
Soil biology measurements were taken before and after grazing each year. Based on both the microbial analysis report and the nutrient analysis, there was no consistent or discernible effect on most soil health markers. The variables were strongly affected by seasonal conditions though, and were consistently very similar across treatments. These changes are driven by soil temperature and moisture conditions. At the last sampling time in 2021 the ratio of protozoa to bacteria was slight higher in the grazing plots than in the cover crop only and the check plots (Figure 1). The difference was statistically significant at alpha = 0.1 with the check plots only. A higher ratio indicates an active community with sufficient nutrients to support higher trophic levels. Related to this, the amount of biomarker fatty acids originating from eukaryotic organisms were also higher in the grazing plots than in both the check and cover crop only plots, statistically different (alpha = 0.1) with the cover crop only plot (Figure 2).
Cattle were grazed each year of the study. However, corn plots could not be grazed in 2019 due to the late snow storm. So only wheat plots were grazed. In 2020 all plots were grazed, but wheat plots could only be grazed for seven days due to the limited biomass growth of the cover crops and no straw to supplement. Cattle performance was not measured followed 2020 wheat grazing due to this limited time-frame. In 2019 wheat cover crop biomass averaged 1800 lb/a dry matter. In 2020 the corn dry matter weight, including stalks was 7500 lb/a and wheat cover crops were 800 lb/a. Cattle performance on the cover crops was as follows: following wheat cattle gained 1.69 lb/day compared to drylot which gained 3.9 lb/a. Following corn, cattle gained 1.4 lb/day compared to 2.91 lb/day in drylot. Marbling was measured with ultrasound on each of the grazed and drylot cattle for each year of the study. No quality differences were detected through this comparison.
In 2020 we switched the farmer cooperators from aerial broadcast to ground-based broadcast seeding. In 2019 it was difficult to arrange aerial applications due to limited availability of aerial seeding platforms, and competition with time demands for custom aerial spraying. The ground applications improved overall satisfaction with the broadcast seeding practice among farmers and researchers. One grower was not able to seed in 2020 and but was able to complete the task in 2021. Overall, cereal rye establishment was poor at all locations and years. These two years also had very dry summers. There was some limited emergence of the cover crop late in the wet fall of 2019, but snow conditions prevented utilization of the cover crops. Farmers were still able to graze corn stalks on these fields.
For cash crop harvest, the average spring wheat production was equal across all treatments (Table 1). This would be expected as none of the treatments were imposed until after harvest. The corn production was also similar across treatments. In this case, the cover crop was planted mid-season, but no grazing would have occurred until after harvest.
|
Treatment |
Spring Wheat yield (bu/a) | Corn yield (bu/a) |
| No cover crop or grazing | 43.2 | 163.3 |
| Cover crop but no grazing | 42.9 | 162.2 |
| Cover crop and grazing | 45.3 | 156.2 |
Corn was planted across all treatments the following year to test for differences. No differences in subsequent corn yield was detected either year for any treatment combination.
Costs and net returns were applied to the yields and cattle performance for the duration of the study (Table 2). Net returns on cash crop treatments were less when adding cover crops, except for the cover crop + grazing treatment on wheat (thought this was likely an anomaly due to yield coincidentally being higher). When compared to drylot, grazing costs were quite a bit lower per head. This was particularly true for the corn plots. The main difference was the amount of days the cows grazed in the corn. The longer grazing period created greater separation of costs as the grazing was more efficient each day of utilization compared to drylot which is a fixed cost per day. Net return on grazing vs drylot was not calculated as there are many variables that affect the sale timing. The difference in costs between grazing and drylot was calculated for the duration of this study, which was $13.55 for the wheat system and $59.23 for the corn system, based on the area that was grazed. When added to the net return of the cash crop grazing, both the wheat and the corn system with grazing became the top performing treatment.
For soil compaction we were expecting to see some short lived compaction layers near the water tanks with reduced compaction as the distance became greater. Our soil penetrometer readings were all below 2000 kPA which is the value where plant root inhibition might be impacted. So, the compaction tests that were performed indicated that none of the treatments, which include cover crops, cattle, and cash crop in combinations, had any impact on overall compaction at the site. This is both good and bad. It is good that the cattle did not cause any compaction issues, but also the cover crops did not reduce compaction any further. This can partly be explained by the low number of grazable days. Each year, grazing duration was relatively short due to the difficulty of getting cover crops with sufficient growth, particularly in wheat.
With soil biology we are once again maybe not seeing many differences here due to the short duration of the grazing and limited cover crop growth. However, it is encouraging to see the soil health indicators of protozoa/bacteria ratio and fatty acids from eukaryotic species increase after even limited grazing sessions. Soil biology ecosystems are being shifted as a result of the introduction of cattle to the system which increases diversity and function of the soil microbiome in those areas exposed to animals.
Animal performance in this study was poor in grazed plots compared to drylot cattle. The grazing opportunities in this study were not great due again to the weather conditions these two years. Not only was the cover crop growth limited, each year saw snowfall events during the grazing period which were difficult for the cattle. The grazing took place the second half of October each year during abnormally cold and snowy conditions. However, there were cost and feed supply savings associated with grazing the cattle vs feeding them during this period which would partially offset the difference in daily gain between the sets of treatments. We were able to set out time-lapse cameras that helped understand cattle traffic as well. This demonstrated that the animals were regularly moving throughout the entire enclosures each day.
Farmer cooperators did not have very good luck with cover crop seeding. Only one of the six sites (3 farmers x 2 years) had cover crops established, but even it was a low amount. Farmers still grazed the corn residue, so they were able to get some value out of the collaboration. Aerial seeding was a poor option in our region. The goal for these applications is to time them just before rain events, however, the optimum timing for corn cover crop seeding is the same as fungicide timing for cereal grains. Aerial seeds are set up primarily for fungicide applications. We worked with two crop dusters, and neither were able to get the cover crops seeded in a timely manner. The fields were seeded three (1 field) and four (2 fields) weeks after our target date due to them being too busy to change equipment setup. In 2020, the ground applicators were much more reliable as there were more people willing to do that seeding and less competition for equipment time since most commercial herbicide applications were completed by this time. Neither aerial nor ground application made a difference in cover crop establishment, but the ground units would be the preferred application method due to logistics.
Our recommendation going forward is to transition more cover crops into corn cropping systems. Mid-season planting appears to be the best solution. However broadcasting has proven to be very unreliable. Our trials were more successful than grower experiments largely because we were able to use a modified planter to place the seeds in dirt. Corn interseeded with cover crops, using a planter, have since proven to work each year it has been tried. This provides growers with the ability to grazing corn stalks, dropped cobs, and cover crops on the same field. Our study was designed for fall grazing. However, results would have been better if we were able to spring graze the cattle. With a corn cover crop system, a grower could decide which timing works better for them. A combination of rye plus brassica cover crops would mean there is grazing potential at either timing. So if corn harvest is delayed in the fall, a spring grazing scenario could still offer good opportunities for cattle producers. In a fall cover crop/wheat system, much of this is not true. The success and failure of the fall cover crop comes down to fall moisture and temperature. Neither of which are guarantees in North Dakota.
Cash crop performance in this study was not expected to change by treatments. There was a chance that cover crops could have competed with corn and caused a yield drag. There was a numerical drop in corn yield in this trial as a result of cover crops but not enough to be statistically significant. We believed there could be a difference the subsequent year with the corn test crop. None was detected. This is both good and bad. This indicates that no change in practice was negatively impacting crop yields. It also indicates no benefit to this change in practice, at least in the short term. With longer growing periods, longer grazing duration, and more years of cover crops or grazing, treatment differences would be more likely. The duration of this study likely limited the noticeable effects to a cropping system.
Economic returns were highest with the cover crop grazing, as long as the drylot expenses are factored into production. When one can save on drylot expenses and instead utilize the cropland for grazing, there can be substantial differences is cost savings. The benefit of grazing increases substantially the longer the grazing period. This is because the majority of costs for grazing are up-front and making it more efficient the longer the duration. Drylot costs per day fixed. The period of grazing here was not long for either corn or wheat due to limited biomass. With longer grazing periods, the net return on cash crop + grazing (vs cash crop + feedlot) will be even larger. However the weather risks of fall grazing could reduce the ability to capture this difference some years, whereas the drylot feeding is more predictable.
Overall, this was a difficult study to work with. Many of our plans did not pan out as we had hoped. But we did come away with many important lessons from these failures, many of which are stated above. We are able to continue to educate producers on the best cover crop management practices for our area, including what to expect or not expect if grazing is of interest. Our experiences do not differ much from our target audience for this project. In many cases farmers are reporting similar outcomes to cover crop implementation (poor growth or establishment, limited grazing potential). This feedback and our experiences are important to increasing the chances for success in a cover crop or integrated system. We now have much better information to share with producers. We are now working on research reports and outreach plans that summarize the various aspects of this study. For instance we are putting together a more thorough report involving the microbial findings, and another more comprehensive article about the compaction data. We feel confident that we can work with producers to help them get started in a cover crop grazing scenario that reduces risk and increases the chances of satisfaction with the practice.
Education
There are two primary forms of education associated with the project; on-farm demonstration and cafe talks. There are three farmer cooperators associated with this project that will be testing on-farm cover crops for grazing, utilizing commercial cover crop seed spreaders (aerial or ground-based). Farm walks are included in the fall in corn fields that have had cover crops spread. The other component of education is the the cafe talk aspect that occurs during the winter months. This included some virtual meetings in the second year. These talks encourage one-on-one interactions and lets the growers dictate the topic coverage and facilitates grower-to-grower interaction.
Project Activities
Educational & Outreach Activities
Participation Summary:
With Covid-19 the 2020 outreach activities were minimal. However we were able to do a two additional virtual format presentations with mainly-farmer attendance.
In 2021, we had slots on 5 field tours and 3 workshops. One of the field tours was a train-the-trainer event consisting of 13 county Extension agents from the surrounding area. That entire tour was focused on different aspects of this SARE project but also including a stop for manure composting and fencing options for field grazing. We were able to reach an additional 208 farmers and other ag professionals as part of other field tours and 207 farmers and consultants at winter workshops. This was a very nice increase compared to the year before.
Learning Outcomes
- Strategies for increasing cover crop establishment following or within cash crops
- Reasons cover crops have failed to establish
- Biological and chemical weed management synergies with cover crops
- Realistic expections for grazing durations in North Dakota
Project Outcomes
Do not use aerial seeding for cover crops, will only plant/seed cover crops
Maintain the use of herbicides to work with a cover crop system
Would consider mid-season planting of cover crops