Project : USDA ARS

ARS Home » Midwest Area » Morris, Minnesota » Soil Management Research » Research » Research Project #437622

Research Project: Optimizing Oilseed and Alternative Grain Crops: Innovative Production Systems and Agroecosystem Services

Location: Soil Management Research

2024 Annual Report

Objectives
Our overall goal is to develop multipurpose alternative oilseed and grain crops and innovative crop management strategies to diversify agricultural systems, reduce and/or efficiently utilize agricultural inputs, and add new economic opportunities and agroecosystem services for crop production in the Upper Midwest region. Over the next five years our research will focus on the following objective: Objective 1: Identify sustainable alternative crops that complement corn and soybean and develop innovative production systems suitable for the Upper Midwest that efficiently use agricultural inputs and provide agroecosystem services, as well as new economic opportunities for end users. • Subobjective 1A. Identify alternative oilseed crop genotypes with improved agronomic traits such as abiotic stress tolerance and reduced seed shattering that optimize productivity. • Subobjective 1B. Develop new and improve existing practices for managing alternative oilseed crops and traditional crops to produce food, feed, and fuel while providing agroecosystem services (e.g., reducing soil erosion, scavenging excess N & P, and supporting pollinators). • Subobjective 1C. Develop new and improve existing double- and relay-crop sequences with winter oilseed cover crops while protecting soils, suppressing weeds, and promoting pollinator abundance and diversity throughout the growing season. • Subobjective 1D. Determine interactions of climate, soils, plants, and agricultural management on agroecosystem functions of pollinator forage and nutrition, crop nutrient capture and usage, soil GHG emissions, and carbon dynamics in novel and traditional cropping systems.

Approach
Our primary objective and overall goal is to develop new crops and innovative strategies to deploy them across the agricultural landscape to diversify Midwestern cropping systems, reduce or minimize negative impact, and improve economic and environmental sustainability while enhancing production. The following approaches will be taken to accomplish this: 1) identify new and alternative oilseed and small grain genotypes best suited for production in the Northern Corn Belt region, 2) develop best management practices for their production, 3) integrate them with traditional crops into innovative cropping systems (e.g., double- and relay-cropping) to sustainably intensify crop production, and 4) develop a better understanding of the impact of climate, soils, plants, and crop management on pollinator forage and nutrition, crop nutrient capture and usage, soil greenhouse gas emissions, and carbon dynamics in new and traditional cropping systems. These new crops and cropping systems will provide new economic opportunities, create healthier food choices, and increase agricultural input-use efficiency while adding agroecosystem benefits such as improved soil, air, and water quality and abundant resources to sustain healthy pollinator populations. Together, the outcomes of this research will enhance agricultural land-use efficiency and benefit U.S. farmers, rural communities, human health, chemical and food industries, as well as government and academia scientists.

Progress Report
In support of Sub-objective 1B, we will complete data collection (year 2) for two multilocation pennycress experiments in collaboration with three university partners in FY24. One experiment focuses on determining establishment and productivity of golden seeded (domesticated) pennycress following common Midwestern summer annual crops that include wheat, soybean, and corn (harvested for both grain and silage). At two experiment sites in Minnesota, pennycress established better and produced higher seed yield when planted after spring wheat and silage corn than planted after soybean or grain corn. Similarly, double crop soybean yields were higher after pennycress that was planted after silage corn and wheat. The second experiment focuses on identifying the optimum time to plant golden pennycress. Results indicate that the optimum planting time to achieve highest seed yield is from late August to mid-September. Also, the earlier pennycress is planted, the earlier it is harvested the following summer, which leads to better double crop soybean yields following pennycress harvest. In support of Sub-objective 1C, we completed a double cropping study with early maturing winter camelina double cropped with dry edible beans, sunflower, and millet. Data has been statistically analyzed and a peer-reviewed paper is being prepared. Results will be presented at an international society meeting. Seed yields of the early winter camelina variety EF9 were not different than that of the standard line (Joelle), used in our past research, but oil content of its seed was about 2 to 3% lower. Double-cropped grain yields of dry bean and millet were not different than if they were grown as a sole crop (no winter camelina). However, double crop sunflower seed yield was consistently 20% lower than monocrop sunflower, but the content and quality of their oil were the same. Soil water content and seasonal water use were also measured in the study. Double cropping used more seasonal water than growing a sole crop. Double cropped sunflower used about 4 inches more water during the growing season than monocrop sunflower, which could limit its use in drier environments. Identifying agronomically viable double cropping options will help increase farmer adoption of producing camelina for industrial uses such as biofuels. In support of Sub-objective 1C, we replicated a study to evaluate the agronomics of relay cropping (i.e., interseeding) winter camelina with sunflower, safflower, chickpea, and soybean. For the relay treatments with sunflower, chickpea, and soybean, one set of plots consisted of winter camelina interseeded in the fall with tillage radish and another complementary set of plots without tillage radish. Hypotheses were to determine whether tillage radish provides a better seedbed for establishing the relay crops the following spring, and if radish, which winterkills, provides an additional source of soil nitrogen (N) for camelina growth in the spring. Additionally, soil N levels between fall and spring with and without fall interseeded tillage radish and interactions with pollinators as described above are being evaluated in the study. Initial results indicate that fall tillage radish increased spring water infiltration but did not affect camelina or relay crop yields. First year yields were lower in the relay plots than the monocrop plots, the unusually dry 2023 spring affected relay crop establishment. The replicated study will be complete in fall 2024 and results presented at a 2024 international meeting. In support of Sub-objective 1D, we continued to measure and compare soil greenhouse gas fluxes between a wheat-winter camelina-relayed soybean rotation (OCC; oilseed cover crop system), that provides winter plant cover and minimal tillage and a conventional corn-soybean rotation (BAU; business as usual) with fall and spring tillage and no winter cover. This past year, the OCC system was rotated from wheat to winter camelina (planted in the fall) and has been relay interseeded with soybean (in spring), whereas the BAU was corn last summer and was planted to soybean this summer. In comparison, both systems had similar carbon dioxide (CO2) and nitrous oxide (N2O) fluxes from their soil in the fall (Sept-Nov). However, in spring (Feb-May) soil CO2 and N2O fluxes were considerably higher in the OCC system than the BAU. Because of a mild winter, camelina began growing very early. This, combined with higher-than-normal soil temperatures may have led to earlier soil microbial activity, resulting in higher greenhouse gas fluxes from soil in the OCC system. Data will continue to be collected until spring 2025. Results will be analyzed and summarized for publication. In support of Sub-objectives 1B-1D, we conducted field and greenhouse studies to evaluate golden pennycress tolerance to herbicides and herbicide carryover. In experiment one, common soybean herbicides were applied to soybean in June 2023 and pennycress was broadcast-seeded in the fall. Pennycress stand density, canopy cover, and phytotoxicity in response to herbicide carryover were evaluated in the fall and spring, and pennycress yield will be measured. Soybean herbicides that included active ingredients that inhibited the acetolactate synthase enzyme (ALS-inhibitors, Group 2 herbicides) caused severe stand loss and reduced canopy cover. In experiment two, corn and soybean herbicides that had caused minimal injury to pennycress in greenhouse dose-response studies were applied immediately after pennycress was drilled into wheat stubble. Pennycress stand density and canopy cover were evaluated in fall and spring, and yield will be measured. Group 3 herbicides (microtubule inhibitors) did not cause stand loss or measurable injury. Five Group 15 herbicides (s-metolachlor, acetochlor, dimethenamid-p, flufenact and pyroxasulfone (very long-chain fatty acid inhibitors), and two Group 27 herbicides (tolpyralate and topramezone) caused little to no injury and stand loss. In experiment three, herbicides were applied postemergence in the spring at the beginning of pennycress bolting. No injury was detected from Group 15, Group 1 (ACCase inhibitors), or Group 4 (synthetic auxin) herbicides that were tested. In the greenhouse, a series of dose-response studies were conducted to simulate herbicide carryover in the soil at different intervals from herbicide application. Herbicides commonly used in corn and soybean were evaluated. Data from greenhouse and field studies are being combined for manuscripts and to provide data for herbicide registrants to consider listing pennycress on labels as a rotation crop, or as a crop where a herbicide might be used. In support of Sub-objectives 1C and 1D, we initiated a study to quantify winter camelina floral resources for pollinators, evaluate pollen composition, and monitor insect visitation to flowering camelina in both double and relay cropping systems with summer annual crops. Light reflectance indices measured with both a handheld device and drone were found to correlate with visual percent flower cover. Winter camelina flowers were visited by numerous insects including honeybees and bumble bees but mostly by small native bees and beneficial flies. Collected flower samples in the field and sent to an ARS collaborator in Tucson, Arizona. Winter camelina pollen was found to be rich in omega-3 and omega-6 unsaturated fatty acids as compared with other flowering species. Pollen is a primary source of fatty acids for pollinators and omega-3 and -6 fatty acids are known to contribute to good bee nutrition. Pollen was collected from the 2023 crop at two locations and three flowering times. Initial results were not conclusive for effect of location and bloom time on total protein, total lipids, or the ratio of protein to lipid. Pollen samples collected in spring 2024 were sent to the Tucson lab for analysis. Protocols are continually refined for using a pollen vacuum to collect bulk pollen from winter camelina that will be analyzed for more complex lipid and amino acid characterization. In support of Sub-objective 1B and 1C, we completed a collaborative study with a university partner to evaluate four ecotypes of sunn hemp (Crotalaria juncea L.) for differences in biomass accumulation, nutritional quality, and alkaloid accumulation across three harvest times and two growing environments for sunn hemp. Sunn hemp is a warm season annual legume with rapid biomass accumulation that is used for livestock feed and to improve soil health. Sunn hemp ecotypes were planted in June 2022 and 2023 and weekly measurements collected of plant growth, and harvested biomass at 45, 60, and 90 days after planting at two locations. Sunn hemp produced high quality and quantity of biomass suitable for animal forage. Results were presented at an international meeting and are being prepared for publication. The sunn hemp variety used in June 2023 was planted again in 2024 at six seeding rates at two locations and weekly measurements made on plant growth. Results indicate that sunn hemp has a plastic yield response to seeding rate and maintains biomass accumulation across a wide range of rates. In support of Sub-objective 1D, we initiated a collaborative study with a university partner to quantify visitation of different pollinator groups (domestic and native bees, syrphid flies, etc.) on perennial flax across multiple locations. Objectives include identifying if perennial flax is used by pollinators, quantifying the seasonal duration of pollinator forage resources provided by perennial flax, and identifying if certain varieties of perennial flax are more attractive to pollinators. Initial results indicate that visitation and diversity of pollinators is responsive to flax varieties. Observations will continue in 2024.

Accomplishments
1. Seed coatings and treatments on black-seeded pennycress improved establishment. Pennycress is a new oilseed crop that has very small seeds making it challenging to plant. Treating the seeds with the plant hormone gibberellic acid (GA) and fungicides might increase germination, while coating the seeds with a commercially available clay-based compound increases their size making them easier to plant. ARS researchers at Morris, Minnesota, collaborated with several university partners to evaluate combinations of seed coatings and treatments on black-seeded and yellow-seeded pennycress lines under laboratory and field conditions. Seed germination, seedling emergence, and ultimately seed yield were greatly improved in black-seeded pennycress lines whose seed was treated with GA and coated. However, yellow-seeded lines did not benefit from either seed coating or GA treatment, and even showed a yield reduction from coating. Yellow-seeded pennycress has a mutation that causes its seed coat to be thinner than the black lines, which may explain the different results for the two types. Results will help the specialty seed industry and farmers decide on which pennycress lines will benefit from having their seeds coated and treated with GA and fungicide before planting.

2. Pennycress flowers provide food for an abundance and diversity of pollinating insects. Pennycress is a new winter annual cash cover crop for the upper Midwest that flowers early in the spring and is known to attract pollinating insects. However, little is known about the specific types of visiting pollinators. ARS researchers at Morris, Minnesota, in collaboration with several university partners, investigated the abundance and species diversity of pollinating insects visiting pennycress flowers across a wide agricultural landscape from western Minnesota to central Illinois. A total of 28 different native and domestic bee species and 16 fly species were identified. Abundance and diversity of bees decreased as the percent of land area devoted to annual row crops such as corn and soybean increased. Results indicate that including pennycress in Midwestern cropping systems will enhance pollinator diversity and abundance. Results benefit apiarists, ecologists, conservationists, Natural Resource Conservation Service personnel, and growers interested in alternative crops that can promote pollinator abundance and health.

3. Corn stover removal has little impact on pennycress emergence and seed yield. Lack of agronomic best management practices is a barrier to introducing pennycress to the Upper Midwestern cropping systems. Establishing pennycress in corn-based systems has been challenging. ARS researchers at Morris, Minnesota, in collaboration with the University of Minnesota conducted experiments at two locations in Minnesota to evaluate pennycress establishment and yield after planting into standing corn. At corn harvest, 0 to 100% of the corn stover (aboveground plant material) was removed. Pennycress germination and emergence suffered from lack of light after planting into standing corn. However, removal of corn stover after harvest had little or no impact on pennycress growth in the fall or its seed yield the following summer. Yields of pennycress were relatively high averaging 1120 lb/acre. This information benefits farmers, extension educators, and other ag professionals interested in incorporating pennycress into Midwest cropping systems.

4. Camelina is a good fit for dry, high stress environments as biofuel feedstock. Demand for vegetable oil worldwide is outpacing supply. Alternative oilseed crops can serve as rotational crops for the U.S. to diversify cropping systems and help meet oil demands. ARS researchers at Morris, Minnesota, collaborated with ARS scientists in Mandan, North Dakota and Sidney, Montana to evaluate seed yields and seasonal water use of canola, camelina, and white mustard across three environments with declining gradients in precipitation and temperature from east to west. At each site, all three oilseeds used similar amounts of water for their growth. However, in the low stress environment of Minnesota, canola out yielded camelina and mustard and had the greatest water use efficiency. Conversely, in the drier, high stress environments of North Dakota and Montana, camelina performed as well or better than canola and mustard. Because camelina requires low inputs, it may be a better choice to produce in dry, stressful environments, whereas canola is a better choice for high-yielding environments. Results will benefit farmers and the vegetable oil industry interested in pursuing alternative feedstocks for biofuels.

5. Winter camelina has a low nitrogen fertilizer requirement. Winter camelina has a low nitrogen fertilizer requirement. Winter camelina is grown as an "offseason" winter crop between summer annuals in the Upper Midwest, thus helping to diversify agricultural systems and add new economic opportunity. ARS researchers at Morris, Minnesota, in collaboration with University of Minnesota, conducted a study to evaluate nitrogen fertilizer rate and application timing to optimize winter camelina seed yield across three different field sites in Minnesota. Results demonstrated that only 30 to 60 lbs/acre of nitrogen, applied in the spring when the plants are actively growing, is necessary to optimize winter camelina seed and oil yield. Camelina’s nitrogen fertilizer requirement is much lower than the 140 to 160 lbs/acre of nitrogen required for a corn crop. Results will benefit farmers and other ag professionals by guiding them to make scientifically informed decisions on how much and when to apply nitrogen fertilizer to winter camelina.

U.S. DEPARTMENT OF AGRICULTURE

Soil Management Research: Morris, MN