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

2023 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 completed two multilocation studies with three different university collaborators. The first evaluated the effectiveness of various seed coatings applied to pennycress seed to improve field emergence after planting. The coatings consisted of different combinations of gibberellic acid (GA), a fungicide, and commercial pelleting material which were used to coat/pellet two different pennycress lines, one black- and one yellow-seeded. The black-seeded line had better establishment and yield when planted seeds were treated with GA or coated with GA plus the pelleting material than untreated seeds. However, the yellow-seeded line did not benefit from any of the coating treatments and its emergence was reduced by up to 40% when pelleted. Two peer-reviewed manuscripts for this work have been submitted for publication. The second study compared productivity of black- and yellow-seeded pennycress lines that were broadcast planted into vertically tilled soil (disking) following a 90-day maturity corn hybrid. The black-seeded line resulted in better stands and soil cover than the yellow-seeded variety, but their seed yields were not different. However, yellow-seeded pennycress had higher oil content (35%) than the black-seeded line (31%). Soybean was double cropped after pennycress harvest, and despite a very dry summer, it yielded about 22 bushels/acre regardless of the pennycress line it was planted after. In support of Sub-objective 1B, we repeated two new multilocation pennycress experiments in collaboration with three different university partners this fiscal year. One addresses establishment and productivity of Golden Pennycress (yellow-seeded commercial variety) following spring wheat, soybean, grain corn (86-day maturity), and silage corn. We collected and analyzed grain yields of wheat, soybean, and corn for the first year and planted pennycress in the fall. Pennycress provided optimum fall emergence and spring cover following silage corn and wheat at northern U.S. sites, while further south, emergence and cover were optimized when following soybean and silage corn. Following pennycress harvest, soybean will be grown as a double crop. The second experiment evaluates optimum planting date for Golden Pennycress. Results for year-1 indicate that emergence in the fall is optimized by planting in early to mid-September. Fall-emergence was minimal for later plantings (late September through October), but several plants emerged in the spring. Previous research shows that spring-emerged plants yield less than fall-emerged ones. Pennycress plant biomass, seed yields, and seed quality are being collected and analyzed. The experiment will be repeated this fall. In support of Sub-objective 1B, we initiated a study to determine which commonly used soybean preemergence herbicides pose a carryover risk to fall-planted pennycress. Applied herbicides and planted soybean. Pennycress will be planted Fall 2023 following soybean harvest, and assessed for stand, injury, and yield. In support of Sub-objective 1B and 1C, we initiated a collaborative study with a university partner to evaluate four ecotypes of sunn hemp for differences in biomass accumulation, nutritional quality, and alkaloid accumulation across three harvest times and two growing environments and identify optimal seeding rates for sunn hemp across two growing environments. Sunn hemp is a warm season annual legume with rapid biomass accumulation that is used for livestock feed and to improve soil health. Tested hypotheses to determine whether sunn hemp ecotypes vary in forage quality and how location affects growth. Planted sunn hemp ecotypes in June 2022 and 2023 at ARS and Cooperator research farms. Weekly measurements of plant growth will be collected, and biomass will be harvested 45, 60, and 90 days after planting at both locations. Biomass will be analyzed for feed quality and alkaloid levels. Preliminary findings showed that sunn hemp produced high quality and quantity of biomass that is suitable for animal forage. Findings will be presented at a 2023 international meeting. A single ecotype of sunn hemp will be planted in June of 2023 and 2024 at six seeding rates at ARS and Cooperator research farms. Weekly measurements of plant growth will be made, and biomass will be harvested at 30, 60, and 90 days after planting to determine optimal regional seeding rates for biomass production. In support of Sub-objective 1C, we replicated a double-cropping study with early maturing winter camelina this year. Results showed that the early maturing variety (EF9) yielded as high as the standard later maturing variety (Joelle) used in most of our previous studies. However, EF9’s seed oil content (37%) was slightly lower than Joelle (39%). Harvested the EF9 camelina by late June and then followed with sunflower, dry bean, and millet as double crops. Grain yields of dry bean and millet were as high or higher than their monocrop counterparts planted June 3 (normal planting date) after winter fallow. Double crop sunflower grain yield was 20% lower than its monocrop counterpart. Soil moisture during the summer was generally as high or higher in the double crop plots as the monocrop plots, but for sunflower it was the opposite, which probably contributed to lower double crop yields. Overall grain yields of the double crop systems (both crops combined) were greater than growing each separately as a monocrop. In support of Sub-objective 1C, we initiated 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. Tested hypotheses to determine whether tillage radish provides a better seedbed for establishing the relay crops the following spring, and if radish provides an additional source of soil nitrogen (N) for camelina growth in the spring. Tillage radish flourishes in the fall but is killed by freezing in the winter, and presumably releases N to soil from its decomposition that can be used 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. Initially, camelina stands overwintered relatively well. Soil samples, soil moisture, camelina stand counts and biomass samples have been taken, and flower counts and samples for pollen along with light reflectance measurements have been taken. These data will be analyzed later this fall. Crops will be harvested later this summer and analyzed for yield and grain quality. Soil moisture in spring/early summer was slightly higher throughout the soil profile in plots that had tillage radish, indicating that potentially the radish provided better infiltration of water from snowmelt and spring rains. 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. Collected pollen from the 2023 crop at two locations and three flowering times to determine the impact of climate and growth stage on pollen quality. 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 soil cover. Results so far indicate little difference in soil carbon dioxide (CO2) emissions between the two systems from spring to late fall/winter. However, soil nitrous oxide (N2O) fluxes did tend to be higher during late spring/early summer in the BAU treatment as compared with the OCC treatment. Nitrous oxide is a greenhouse gas that has about 300 times greater global warming potential than CO2. Plots used for this study are included in the Long-Term Agricultural Research (LTAR) network complementary to an on-farm project and as such, we will continue to monitor soil gas fluxes to better understand long-term implications of these cropping systems on climate change. In support of Sub-objective 1D, we initiated a collaborative study with a university partner to quantify visitation of different pollinator groups (honey bees, bumble bees, native bees, syrphid flies, etc.) on perennial flax varieties 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. Pollinator visitation monitoring started at the beginning of June will be done every two weeks throughout flowering. Data on visiting insects across locations and varieties will be analyzed in fall/winter.

Accomplishments
1. Improving agricultural management of pennycress production. Pennycress is a new winter oilseed crop that can be used for biofuels and bioproducts. It can be planted in fall after corn, soybean, or wheat and relay-cropped the following summer with soybean thereby producing two crops on the same land in a single year. ARS researchers in Morris, Minnesota, demonstrated that with proper soybean planting time and variety selection, soybean yield can be maximized without damaging pennycress. In collaboration with a university partner, the researchers also showed that because pennycress seeds mature rapidly it could be direct harvested without swathing (cutting and drying before combining) to reduce harvest time. In addition, they verified that the cooperator’s new improved pennycress line was less prone to shatter seed thus, improving yield. An industry partner is currently poised to initiate pennycress commercialization. Results benefit farmers interested in producing pennycress and relay-cropping, university extension specialists, ag consultants, industry partners, and other scientists seeking ways to improve pennycress production.

2. Mid-range maturity corn allows better pennycress fall establishment without sacrificing grain yield. Planting pennycress after corn harvest presents challenges in the upper Midwest because corn is harvested late in the fall. ARS researchers in Morris, Minnesota, in collaboration with three university partners, evaluated using early relative maturity corn hybrids (CRM) to allow earlier fall establishment of pennycress to improve its growth and yield. Results demonstrated that across the Corn Belt Region, growing a mid-range maturing CRM allowed better establishment and yield of pennycress without losing corn grain yield compared with a full-season CRM. Also, the use of an early CRM allowed earlier pennycress harvest followed by earlier planting of soybean as a double crop. This management adjustment for the system will likely improve economic returns making it more attractive to farmers. Results benefit farmers, ag consultants, and industry partners interested in growing pennycress in a corn-soybean rotation and researchers seeking ways to improve the integration of pennycress into Midwestern cropping systems.

3. Winter camelina greatly reduces early summer weed growth. The use of winter oilseeds as cash cover crops is gaining popularity. Previous study indicates that certain winter mustard oilseed species with good freeze-hardiness can suppress early summer weeds including herbicide resistant ones. A collaborative study between researchers in Morris, Minnesota, and Fargo, North Dakota, was conducted at both locations to determine winter survival and weed suppression traits of winter camelina and several winter canola lines selected for improved winter survival. Winter camelina had much greater winter survival than canola, and the following spring, camelina suppressed weed biomass by >90% at both sites. Results revealed winter-hardy lines of winter canola useful for breeding to improve freeze tolerance in commercial varieties. Results benefit crop breeders and geneticists looking to improve crop freeze-hardiness, and farmers and researchers looking for cropping strategies to improve integrated weed management.

4. Modified intra- and inter-row spacing may improve soybean yield in a winter camelina on soybean nitrogen fixation in a relay system. ARS researchers in Morris, Minnesota, pioneered the development of relay cropping soybean, a legume, with winter camelina and pennycress; both of which are winter annual oilseed crops. Much is known about biological nitrogen fixation (BNF) of conventional soybean. However, nothing is known about soybean BNF when relay-cropped with camelina, and information for this is needed to best manage the system’s productivity. ARS researchers in Morris, Minnesota, showed that nitrogen-fixing bacteria successfully infected and fixed N in relayed soybean roots. However, competition between camelina and soybean during the relay (i.e., intercrop) phase, resulted in lower N-fixation and lower grain yield in relayed compared to conventionally grown soybean. Findings suggest that modifying plant spacing to reduce plant-plant competition during the intercrop phase may boost relayed soybean BNF and yields. Results benefit researchers exploring ways to improve relay cropping productivity and farmers, ag consultants, and extension specialists beginning to implement this new cropping system.

5. Full season sunn hemp biomass accumulation and quality are not affected by the timing of the first cutting, providing the producer maximum flexibility. Legume crops benefit crop and livestock agriculture through nitrogen fixation and providing nutritive, high quality animal feed. Crotalaria juncea (sunn hemp) is a warm season, annual, legume that produces high amounts of biomass, fixes nitrogen, and provides high quality livestock feed making it one of the few viable alternatives when alfalfa is limited. Sunn hemp will regrow after cutting or grazing but there is no recommendation for the optimal timing for the first cutting. ARS researchers in Morris, Minnesota, in collaboration with a university partner showed that the first harvest of sunn hemp biomass between 45 and 105 days after planting did not influence the cumulative full season (first harvest + second harvest of regrowth) biomass yield or nutritive accumulation of sunn hemp produced under dryland conditions in the northern Great Plains. Findings suggest that sunn hemp harvest management can be adjusted based on the needs of the operation without sacrificing quality. These research findings will benefit producers interested in using sunn hemp as a forage crop and extension educators, researchers, and ag consultants interested in adopting sunn hemp into a cropping rotation or feed ration.

6. Refining nitrogen (N) fertilizer recommendation for economic and agronomic benefits. Nitrogen fertilizer is a major input cost for corn producers, and overuse is both uneconomical and leads to air and water contamination. Nitrogen fertilizer rate determination for corn production in Minnesota is mainly based on an online calculator available for the Corn Belt Region, which considers N fertilizer cost, corn grain price, and crop rotation to make a rate recommendation. ARS researchers in Morris, Minnesota, compared results from field study with the recommendation from this calculator to evaluate the net-benefits of using N fertilizer for corn production. Results showed that the tool could be improved for N fertilizer determination by including weather, soil types, and corn hybrid (early vs. late) to better estimate N needed for corn production in Minnesota. Results provide needed information for extension specialists, consultants and producers wanting to know the effects of the current N fertilizer cost and corn grain price on the net benefits of using N fertilizer for corn production.

U.S. DEPARTMENT OF AGRICULTURE

Soil Management Research: Morris, MN