Location: Northwest Irrigation and Soils Research
2023 Annual Report
Objectives
Objective 1: Develop improved practices and strategies for managing inputs in irrigated cropping systems to increase soil health, optimize crop productivity and quality, and minimize negative environmental impacts.
Sub-objective 1A: Identify effects of fertilizer source, timing of application, and nitrification/urease inhibitors on nutrient cycling and field-scale nutrient budgets.
Sub-objective 1B: Identify effects of past manure application rate and frequency on biological indicators of soil health, nutrient cycling, and field-scale nutrient budgets.
Sub-objective 1C: Determine the efficacy of cover crops and minimum tillage to reduce offsite transport of soil nutrients in a dairy forage crop rotation receiving manure.
Sub-objective 1D: Determine the long-term agronomic economic effects of manure applications on crops, soil nutrient (primarily N, C, and P) cycling, and soil health indicators.
Sub-objective 1E: Determine effects of crop rotation, tillage, and residue management on residue breakdown rates and nutrient cycling in irrigated cropping systems.
Sub-objective 1F: Evaluate aboveground biomass yield, forage quality, and nutrient cycling of sorghum-sudangrass hybrids under multiple management practices (row spacing, number of cuttings, and cultivar).
Objective 2: Quantify gaseous emissions from dairy production facilities and manure-amended soils to improve nutrient cycling and reduce environmental impact of these systems.
Sub-objective 2A: Determine the effect of manure application rate and frequency on soil GHG emissions.
Sub-objective 2B: Determine the effect of manure, cover crop, and minimum tillage on soil GHG emissions.
Sub-objective 2C: Determine ammonia transport and dry deposition in the Magic Valley region and improve accuracy of deposition models.
Approach
Resilient irrigated cropping systems in concentrated dairy production regions require proper management of nutrients to maximize agricultural production while minimizing environmental impacts. Dairy farms in the region generally have more cows and produce more milk than in the past. With the increased number of cattle comes an increased production of manure that must be managed. Crop production coexists in the region with a diverse assortment of crops with varying nutrient needs to meet yield and quality goals. The current project will address crop production and environmental issues that results from concentrated dairy and crop production. Broadly, the project objectives are to improve crop nutrient use efficiency, minimize nutrient and greenhouse gas losses to the environment, investigate novel crops, and determine the impact of crop residues in the agroecosystem. These objectives will lead to improved management practices for irrigated cropping systems in semi-arid environments.
Research consists of several continuing long-term studies along with newly developed projects. Objective 1 is focused on how inputs are managed and effect the agroecosystem. The objective is comprised of seven studies. Long-term studies will evaluate the impact of synthetic fertilizers (with and without nitrification inhibitors in one study) and dairy manure on crop response, nutrient cycling, and soil health. New studies will evaluate impacts of novel cropping approaches, including forage cover crops and grasses such as sorghum-sudangrass, on crop production, nutrient cycling, and soil health. Additionally, these studies will address the impact of crop rotation, tillage, and residue management practices on these factors as well. Objective 2 contains three projects focused on determining gaseous emissions from dairy facilities and manure-amended soils. Long term manure application rate effects on greenhouse gas emissions will be studied. A second study will measure the effects of manure, cover crop, and minimum tillage on greenhouse gas emissions. The final project will determine regional ammonia nitrogen transport to improve models that predict ammonia depositions from the atmosphere to the soil surface.
Progress Report
Research studies were continued in support of Objective 1, where long-term studies continued the evaluation of the use of manure in irrigated dairy forage production systems. These studies are focused on carbon, nitrogen, and phosphorus cycling. Sub-objective 1A included the completion of the tenth year of data collection in Kimberly, Idaho, for the nationwide USDA-ARS GRACEnet project which is assessing the impacts of fertilizer source, timing of application, and nitrification/urease inhibitors on nutrient cycling and nutrient budgets. Manure and compost increased the uptake of nitrogen, phosphorus and potassium and decreased the uptake of calcium and magnesium compared to inorganic fertilizer use. Manure application increased crude protein and crude fat in corn but had no effect on forage quality parameters in alfalfa. This study is entering the third year of alfalfa production where soil health, crop yield, quality, growth, and nutrient uptake and cycling are being analyzed. Nitrogen mineralization is being evaluated in the current growing season using a buried bag technique. This will produce data related to residual nitrogen available to crops following alfalfa with and without manure application.
Sub-objective 1B was supported by the tenth year of continual research evaluating the long-term effects of inorganic fertilizer, dairy manure, tillage, and crop rotation on soil health and crop production. This study is assessing the impacts of past application of manures at varying rates on nutrient cycling and soil nutrient status. Forage barley and silage corn were grown with yields determined and crop samples collected for nutrient content and forage quality. Winter barley and triticale were grown with yields determined in the spring of 2023 and samples collected for nutrient status and forage quality. Yields from manure-treated plots were greater than conventionally fertilized plots. Nitrogen mineralization in treatments that had received manure two years previously ranged from 121 to 235 lbs N/ac, while control plots mineralized 78 lbs N/ac, suggesting that the effect of manure on soil fertility persists for long periods of time. In spring 2023, soil samples were collected to determine nutrient status. Nitrogen mineralization will be evaluated over the 2023 growing season using a buried bag technique to determine the residual nitrogen available to crops from past manure applications. This data will improve our understanding of the value of manure as a fertilizer in forage rotations and the persistence of manure effects on nitrogen cycling and phosphorus budgets, which are a concern for regional producers.
In support of Sub-objective 1C, the eighth year of a study was completed assessing the impact of manure application, tillage, and cover crop on nutrient uptake and cycling. Soil samples were collected and analyzed as in Sub-objectives 1A and 1B. Winter triticale was planted in the fall and harvested in the subsequent spring with yield and forage quality determined. Soil samples were collected in the spring of 2023 to determine soil nutrient status. This data will improve our understanding of how tillage and the use of a winter cover crop affect nutrient cycling in a typical regional forage rotation.
Research associated with Sub-objective 1D focused on manure priming and legacy effects. This included the assessment of the long-term effects of dairy manure applications on crop production and soil properties. Grain and residue yields were determined for barley. Soil and plant samples were analyzed for nutrient concentrations to determine nutrient budgets. Manure treatments are being compared to fertilizer treatments to determine the economic value of manure over time. This data will help determine the feasibility of improved manure distribution and reduced fertilizer input.
Sub-objective 1E evaluated wheat and barley rotations, tillage practice, and residue management. Grain and residue yield were determined, and soil samples collected and analyzed. Research was adjusted to include dry bean rather than sugar beet as the target rotational crop to minimize soil disturbance to the greatest extent possible using a crop commonly grown in the region. These studies have progressed as planned and production for the current growing season is well under-way for both dry bean and barley. Research has indicated that soil health changes are slow to occur in the semi-arid environment of the study and that incorporated residues decompose faster than those left on the surface.
In support of Sub-objective 1F, research on sorghum-sudangrass was conducted. Crop biomass, crop water use, and forage quality were measured. Sorghum-sudangrass diversifies current semi-arid cropping systems in the region as it provides another warm-season grass that can be grown in addition to corn. Preliminary data indicated sorghum-sudangrass yields and nutrient uptake were greater for a single cutting, narrow (7 in) row spacing, and with a conventional variety. Two cuttings in the growing season resulted in decreased yield and nutrient uptake. A brown midrib variety resulted in lower yields than a conventional variety. Row-spacing altered forage quality as wider planting resulted in thicker and denser stems. Management with the least effective practices resulted in a nearly 70 percent (%) reduction in forage yield. This research is providing specific management guidelines to optimize forage production of irrigated sorghum-sudangrass in an intensive dairy production region.
Research continued or was initiated to measure gas emissions from dairy production facilities and manure treated fields in support of Objective 2. Greenhouse gas emissions were measured in semi-arid irrigated cropping systems as well as biological and chemical indicators of soil health and nutrient status. These results, along with future results from Objectives 1 and 2, will be used to identify practices that will improve soil health while minimizing greenhouse gas emissions. In support of Sub-objectives 2A and 2B, greenhouse gas emission data is continuing to be collected and being provided to the U.S. Environmental Protection Agency (USEPA) to be incorporated into national emission inventories. Static gas measurement chambers were installed that provide weekly gas fluxes for both this reporting cycle as well as into the future.
Ammonia deposition research was conducted for Sub-objective 2C with two ammonia deposition towers installed at two regional sites and data collected to determine ammonia deposition. In support of Sub-objective 2C, ammonia monitoring network data was provided to USEPA and other collaborators who utilized it to calculate ammonia deposition in south central Idaho with the Surface Tiled Aerosol and Gaseous Exchange (STAGE) model. This research resulted in identification of model components that must be improved to accurately represent ammonia deposition in semi-arid regions typical of the western United States. Data was also collected and provided to collaborators that allowed comparison of measured ammonia concentrations in the field to satellite imagery.
Accomplishments
1. Improved nitrogen management approach decreases sugar beet fertilizer inputs. Research-based nutrient management practices need to be continuously improved due to changing crop genetics, management practices, and lack of data. ARS researchers in Kimberly, Idaho, determined that the historically used yield goal-based nitrogen management approach was less effective in meeting sugar beet nitrogen needs compared to a new static range nitrogen management approach. The updated guidance is to have 180 to 200 lb/acre of nitrogen available at planting regardless of anticipated crop yield. The static nitrogen approach was adopted by the Amalgamated Sugar Company and the University of Idaho in production guidelines. This recommendation has been implemented across the production area where approximately 20 percent (%) of U.S. sugar beet production is concentrated. At current yield levels and nitrogen fertilizer prices, the static nitrogen approach will reduce fertilizer application rates by 60 to 80 lb/ac saving growers $42 to $56/acre or upwards of $9 million dollars annually.
2. Sugar beet processing lime waste is a significant phosphorus and potassium fertilizer source. Sugar beet processing facilities produce a significant amount of precipitated calcium carbonate (PCC), or sugar beet processing lime waste, during the sugar extraction process. Due to the naturally high concentrations of calcium carbonate in the soil, the PCC is stored in large piles in Idaho rather than applied to fields as occurs in other sugar beet production regions where soil pH in low. ARS researchers in Kimberly, Idaho, studied the effects of PCC on soil properties and crops. The researchers concluded that PCC can be safely applied to fields and the PCC is a good source of phosphorus and potassium fertilizer. Amalgamated Sugar Company is utilizing the research study data to promote the application of PCC on agricultural land as a disposal method for their PCC and as a phosphorus and potassium fertilizer source. In 2023, PCC would have an average fertilizer value of over $4,000,000 across all sugar beet, barley, corn, and potatoes acres in Idaho.
3. Non-growing and growing season nitrous oxide emissions are equivalent in a semi-arid cropping system. Nitrous oxide is a powerful greenhouse gas and emission measurements are needed throughout the year to fully understand annual emissions. Using an automated chamber system, ARS researchers in Kimberly, Idaho, determined that nitrous oxide emissions were significantly greater from manure-treated soil versus those receiving inorganic nitrogen fertilizer. However, regardless of fertilizer source, high nitrous oxide emissions were also found to occur during the colder non-growing season, meaning that non-growing season emissions must be measured to accurately quantify annual emissions in semi-arid climates. This research is being used by scientists internationally who are measuring fallow season greenhouse gas emissions. It is also being used to develop greenhouse gas monitoring protocols for a national study in collaboration with USDA-Natural Resources Conservation Service.
4. Manure and compost applications increase nutrient uptake by forage crops. Nutrient uptake of crops after manure and compost application is less understood than when conventional fertilizers are used. The effects of manure and compost on soil nutrient status, crop nutrient uptake, and forage quality in a dairy forage rotation were assessed by ARS researchers in Kimberly, Idaho. Manure and compost increased the uptake of nitrogen, phosphorus and potassium and decreased the uptake of calcium and magnesium compared to inorganic fertilizer use. Manure application increased crude protein and crude fat in corn but had no effect on forage quality parameters in alfalfa. This research provides dairy producers, universities, and industry groups more accurate values for inclusion in nutrient management plans and nutrient budgets.
5. Winter cover crops increase forage production and nutrient removal after manure application. Manure applications can result in high nutrient concentrations in fields. The effects of a winter cover crop on soil nutrient status, crop nutrient uptake, and forage quality were assessed by ARS researchers in Kimberly, Idaho. Utilizing manure as a nutrient source did not significantly impact silage corn yields but did increase winter triticale silage yields approximately five times that of fertilizer only. Including manure increased crude protein in both silage corn and triticale, while also increasing the fiber content of triticale. Corn and triticale uptake of nitrogen, phosphorus, and potassium were 12-45 percent greater in manure amended treatments compared to synthetic fertilizer only. Including triticale in the rotation increased the nutrient removal 1.1 to 1.8 times that of a field fallow in the winter. Idaho dairy farmers routinely grow triticale in the winter following silage corn to increase nutrient removal and increase forage production.
Review Publications
Tarkalson, D.D., Olsen, D., King, B.A. 2022. Effect of nitrogen supply by soil depth on sugarbeet production and quality. Journal of Sugar Beet Research. 59(1-4):7-22. https://doi.org/10.5274/jsbr.59.1.7.
Bierer, A.M., Dungan, R.S., Tarkalson, D.D., Leytem, A.B. 2023. Fertilization strategy affects crop nutrient concentration and removal in semi-arid U.S. Northwest. Agronomy Journal. 115(1):351-369. https://doi.org/10.1002/agj2.21212.
Hassouna, M., van der Weerden, T.J., Beltran, I., Amon, B., Alfaro, M.A., Anestis, V., Cinar, G., Dragoni, F., Hutchings, N., Leytem, A.B., Maeda, K., Maragou, A., Misselbrook, T., Noble, A., Rychla, A., Salazar, F., Simon, P. 2023. DATAMAN: A global database of methane, nitrous oxide, and ammonia emission factors for livestock housing and outdoor storage of manure. Journal of Environmental Quality. 52(1):207-223. https://doi.org/10.1002/jeq2.20430.
Lee, S., Parsons, C., Chen, Y., Dungan, R.S., Kathariou, S. 2023. Contrasting genetic diversity of Listeria pathogenicity islands 3 and 4 harbored by non-pathogenic Listeria spp. Applied and Environmental Microbiology. 89(2). Article e02097-22. https://doi.org/10.1128/aem.02097-22.
Rogers, C.W., Hu, G., King, B.A. 2023. Deficit irrigation effects on adjunct and all-malt barley yield and quality. Agronomy Journal. 115(3):1161-1173. https://doi.org/10.1002/agj2.21311.
