Location: Agricultural Systems Research
2024 Annual Report
Objectives
Objective 1: Develop management strategies for dryland cereal, pulse, and bioenergy cropping systems that enhance agroecosystem productivity, climate resilience, soil health, and ecosystem services.
Subobjective 1A: Increase cereal-based cropping system resilience using annual or perennial legumes and forages in response to changing precipitation patterns.
Subobjective 1B: Determine novel management strategies that enhance soil C sequestration, improve N cycling, reduce GHG emissions, N fertilization rates, and the potential for N leaching, and promote soil health and quality in dryland cropping systems.
Subojective 1C: Evaluate novel crop species, crop rotations, and sustainable dryland management practices that optimize soil biological health and enhance soil microbial biomass and function.
Subobjective 1D: Improve crop WUE in dryland agro-ecosystems using novel crop species and rotations to improve cropping system resilience and adaptability.
Objective 2: Develop alternative irrigated cropping systems for northern climates that optimize crop production while enhancing environmental sustainability and climate resilience.
Subobjective 2A: Improve early-season plant vigor and final crop yield of NT crops to be more competitive with CT.
Subobjective 2B: Evaluate the effects of reduced tillage and alternative cropping practices on soil compaction, bulk density, aggregate stability, saturated hydraulic conductivity, available water capacity and crop WUE.
Subobjective 2C: Evaluate the effect of residue management and tillage on soil C sequestration and GHG emissions in a NGP irrigated cropping system.
Subobjective 2D: Evaluate the impact of residue management and tillage practices on soil biological health and overall microbial biomass with an emphasis on specific functional groups involved in C and N cycling.
Objective 3: Identify and evaluate indicators that assess improvements in sustainability and resilience of both dryland and irrigated cropping systems in a semi-arid environment.
Subobjective 3A: Improve pollinator habitat in dryland and irrigated agro-ecosystems by establishing relationships between crop management practices and pollinators.
Subobjective 3B: Develop dryland and irrigated cropping systems that reduce risk of pests in rotational crops.
Subobjective 3C: Measure impact of stubble height on evapotranspiration (ETa) under field conditions using weighing lysimeters and develop coefficients (Kc) for crops listed under Hyp. 1.A.
Approach
Agriculture is facing challenges in providing food, fiber and fuel to a growing population due to increasingly limited water supplies, more frequent crop failures, and diminished land resources. Changes in consumer lifestyles and preferences are also impacting agricultural production. For example, longer life spans, rising incomes, and changes in dietary preferences, along with demands for improved nutrition and sustainably-produced food products require researchers to provide farmers with climate-resilient solutions that improve production efficiencies, crop quality, and ecosystem services. In the northern Great Plains (NGP), dryland and irrigated crop production both contribute significantly to the economic value of agricultural production. However, traditional dryland cropping systems with conventional tillage and crop-fallow are uneconomical and unsustainable. Similarly, while unallocated irrigation water resources in the Missouri and Yellowstone rivers offer opportunities to expand irrigated crop production in the MonDak region (eastern MT, western ND), intensive tillage practices used on most irrigated farms are also unsustainable because they lead to high input costs and soil degradation. Diversified dryland and irrigated cropping systems must be developed that are more resilient to changing markets and climatic conditions. Our research plan addresses these needs by utilizing cropping system field trials to develop scientifically-sound no-till dryland and irrigated cropping strategies that improve water, soil, and nutrient management by diversifying crop rotations to include cereals, pulses, oilseeds, forages, and biofuel feedstocks, and thus increase farm productivity and ecosystem services. The research will provide stakeholders with tools to reduce water, equipment, labor, and energy requirements while increasing crop yield and quality and improving soil and environmental ecosystem services. Outcomes and tools will be shared with and transferred to producer groups, partners and stakeholders through research publications, bulletins, online content, field tours, stakeholder meetings, agricultural symposia, and other outreach activities.
Progress Report
Objective 1. 2024 was the establishment year of a 9-year no-till dryland cropping systems study at the Froid site. The general goal is to develop greater cropping system diversity by including pulse, oilseed, and forage crops in continuously cropped no-till wheat systems. Additionally, fall-seeded and perennial forage, grain, and pulse crops will be included to further reduce periods of fallow (i.e. maximize potential for a living root) during the 4-year cropping cycle. An alternative grain harvest method using a stripper header will be tested to quantify improvements in cropping system performance. Crop rotations to be evaluated are: (1) continuous durum, (2) durum-winter camelina-forage winter wheat-pea, (3) intermediate wheatgrass (3-year stand)-durum, (4) intermediate wheatgrass/sainfoin mix (3-year stand)-durum, (5) intermediate wheatgrass (3-year stand)-pea, and (6) intermediate wheatgrass/sainfoin mix (3-year stand)-pea. Crop rotations will range from having no fall-seeded crops with fallow periods occurring 67% of time during the 4-year cycle to sequences with three perennial crops with fallow occurring 23% of time during the 4-year cycle. Harvest management will be Conventional using a standard combine header and intermediate wheatgrass and intermediate wheatgrass/sainfoin mix harvested for forage or Ecological using a stripper header and intermediate wheatgrass and intermediate wheatgrass/sainfoin mix harvested for grain. Soil samples were collected in 2024 to determine base line levels for soil physical, chemical, and biological properties. Durum, pea, winter camelina, and winter wheat were planted to establish the correct residues for the first year of crop production beginning in 2025.
Objective 2. Sugarbeets have been the primary irrigated crop in the region since 1925. However, the recent closure of the local sugarbeet processing factory necessitates the development of alternative irrigated cropping systems. Many farmer stakeholders have turned to corn as a replacement for sugarbeet in rotation with soybean and spring wheat but managing large amounts of crop residues produced by the corn and wheat have caused difficulties under the predominant tillage-intensive management systems. An existing 6-year irrigated sugarbeet cropping systems study was modified beginning in 2024 to develop no-till irrigated cropping systems for northern climates that emphasize environmental sustainability and climate resilience. Tillage treatments (tilled and no-till) in the prior study with a 3-year sugarbeet-pea-wheat rotation were continued with corn and soybean replacing sugarbeet and pea, respectively, in the new study. Wheat and corn residue are either retained or removed in the new study and nitrogen (N) fertilizer for corn is either applied in a single fall application or split between early fall and spring applications. All crops were successfully planted in 2024 and residue and tillage treatments were initiated. Soil samples were obtained for physical, chemical, and biological properties.
Objective 3. Pollinator populations, pest incidence, and soil water availability are three potential indicators of sustainability and resilience in dryland and irrigated cropping systems. We plan to evaluate these indicators in the new dryland and irrigated studies aforementioned in Objectives 1 and 2 with regard to novel crops grown in the Northern Great Plains for food (spring wheat, durum, pea, corn, soybean) for forage (winter wheat) for dual use food or forage (intermediate wheatgrass, sainfoin) and for biofuel feedstocks for industrial-quality oil (camelina); and with regard to management practices related to tillage, crop residue, harvest method, and application timing of fertilizer N. Soil samples were collected in 2024 to determine base line levels for soil physical, chemical, and biological properties. Two existing lysimeters at the Rasmussen dryland research farm were renovated to develop crop water use coefficients under field conditions.
Accomplishments
1. Long-term continuous cropping reduces greenhouse gas emissions. Tilled crop-fallow has been a traditional dryland cropping system in the northern Great Plains. There is a lack of information regarding long-term system effects of tilled crop-fallow on greenhouse gas emissions compared to no-till continuous cropping systems. Scientists at Sidney, Montana, studied the long-term effects of tilled spring wheat-fallow, no-till continuous spring wheat, and no-till spring wheat-pea rotation on greenhouse gas emissions from 2016 to 2018. No-till continuous spring wheat and no-till spring wheat-pea reduced greenhouse gas emissions per unit area as well as per unit crop yield compared to tilled spring wheat-fallow due to increased carbon sequestration. However, crop yields were lower for continuous spring wheat than spring wheat-pea rotation. Hence, no-till spring wheat-pea rotation can reduce greenhouse gas emissions, increase carbon sequestration, and sustain spring wheat yields in the northern Great Plains.
2. Fungicide application does not negatively impact soil biological health in sugarbeet cropping systems. Rhizoctonia root and crown rot is a soil-borne disease that affects an estimated 24% of sugar beet acres in the United States. The impact on yield varies from field to field and from year to year but losses in affected fields are often 40-60% and can be greater in extreme cases. Soil-applied fungicides are typically used to manage the disease and minimize yield loss; however, there are concerns about the impact of fungicides on non-target beneficial soil microorganisms such as mycorrhizal fungi. ARS researchers in Sidney, Montana, evaluated the impact of fungicide use on soil microbial biomass and community composition in sugarbeet-based cropping systems with different levels of tillage and rotation diversity. Results showed greater total bacterial abundance in a 2-year sugarbeet-barley rotation compared to a 4-year rotation of sugarbeet, barley, corn and soybean. There was a higher relative abundance of beneficial microorganisms, including mycorrhizal fungi, in no-till fields than in tilled fields. Notably, fungicide did not impact the soil microbial community composition or microbial biomass regardless of tillage or rotation. Findings suggest that sugarbeet producers can utilize no-till management and soil-applied fungicides to control Rhizoctonia root and crown rot without negatively affecting soil biological communities.
Review Publications
Sainju, U.M. 2024. Dryland soil carbon and nitrogen stocks in response to cropping system and nitrogen fertilization. Environments. 11:70-85. https://doi.org/10.3390/environments11040070.
Sainju, U.M., Pradhan, G. 2024. Pea growth, yield, and quality affected by nitrogen fertilization to previous crop in small grain-pea rotations. Agronomy Journal. 116:1746-1757. https://doi.org/10.1002/agj2.21589.
Zhu, S., Sainju, U.M., Zhang, S., Tan, G., Wen, M., Dou, Y., Yang, R., Chen, J., Zhao, F., Wang, J. 2023. Cover cropping promotes soil carbon sequestration by enhancing microaggregate-protected and mineral-associated carbon. Science of the Total Environment. 908. Article 168330. https://doi.org/10.1016/j.scitotenv.2023.168330.
Rana Dangi, S., Calderon, R.B. 2024. Arbuscular Mycorrhizal fungi and Rhizobium improve nutrient uptake and microbial diversity relative to dryland site-specific soil conditions. Microorganisms. 12:667-687. https://doi.org/10.3390/microorganisms12040667.
Scheffel, A.J., Johnsrude, L., Allen, B.L., Wettstein, S.G. 2023. Composition analysis and environmental factors influencing biomass quality: A comparative study of Montana-grown biomasses. BioEnergy Research. 17:956-963. https://doi.org/10.1007/s12155-023-10690-8.
Sainju, U.M., Allen, B.L. 2024. Carbon footprint and carbon balance of three long-term dryland cropping sequences. Soil Science Society of America Journal. https://doi.org/10.1002/saj2.20703.