Location: Soil and Water Management Research
2020 Annual Report
Objectives
1. Assess the environmental impacts of crop management practices that have the potential to improve soil health and decrease greenhouse gas emissions in the Upper Midwest.
a. Develop a perennialized row crop system that reduces the environmental footprint of agriculture and improves its resilience, without adverse impacts on water usage and profitability.
b. Develop new knowledge regarding soil nitrogen cycling and nitric and nitrous oxide production mechanisms.
c. Develop new knowledge of chemical triggering compounds of microbial activity.
2. Increase nutrient use efficiency and reduce nutrient losses to leaching, runoff and atmospheric emissions in Upper Midwest cropping systems.
a. Develop improved methods to quantify and to reduce losses of reactive N gases from fertilized cropping systems.
b. Evaluate manure management practices for improvement of nutrient cycling and reduction of reactive nitrogen losses on large dairies.
Approach
All the objectives of this project have a common focus on quantifying the impacts of management practices, including crop rotation/cover crops, irrigation, and synthetic N fertilizer or manure amendments, on GHG emissions and nutrient availability for crop uptake or susceptibility to loss to the environment. The different objectives complement each other in several ways. In order to gain insights from multiple perspectives, the methods for each objective range across scales, including large field and larger plot studies (sub-objective 1a); replicated small-plots (2a); soil column mesocosms (2b); and laboratory microcosms (1b, 1c). The same set of soil types representing a range of Minnesota agricultural soils from across the state, including soil from both field experiments (1a and 2a), will be used in the microcosm and mesocosm experiments (1b, 1c and 2b). Thus, results from the three laboratory experiments each of which have different primary objectives, will inform and help to interpret results of the other lab studies; and results from the lab experiments under more controlled conditions will inform results of the field experiments that are subject to dynamic climate conditions. Both of the field experiments (1a and 2a) will measure greenhouse gas emissions and ammonia volatilization losses from cropping systems under similar soil types (the same soil series) but with different management regimes, which may also allow for cross-site comparison of results. This research also complements efforts within several national projects and initiatives, including the Greenhouse Gas Reduction through Agricultural Carbon Enhancement (GRACEnet), Resilient Economic Agricultural Practices (REAP), Dairy Agro-ecosystem Working Group (DAWG) and Long-Term Agricultural Research (LTAR) networks; and as such will involve collaboration with several colleagues from other ARS locations, universities and other organizations.
Progress Report
Sub-objective 1a. We completed the two-year establishment phase of our new kura clover living mulch system (KCLM) which is also our Long-Term Agroecosystem Research (LTAR) field. This effort was necessitated when our former field site was sold by the University of Minnesota. A row crop (corn) was planted into the KCLM for the first time in spring 2020. Within the field, a separate experiment was set up in which three different types of tillage equipment are being tested to determine which is the most effective for establishing corn in the KCLM. Eddy covariance data from the site, along with phenocam data, are being used in the LTAR-phenocam project, in collaboration with ARS researchers at Las Cruces, New Mexico, and other ARS locations across the country.
Sub-objective 1b. Results from soil incubation experiments completed in FY19 were used as the basis for developing a detailed process model (the 2SN model) that describes both steps of nitrification, gas production, and other associated processes. A manuscript describing the 2SN model and reporting a subset of the incubation data was revised and then published in Soil Biology and Biochemistry. The remaining data that includes experiments using the nitrification inhibitor dicyandiamide (DCD) were prepared in a manuscript and submitted to a peer reviewed journal. A separate set of lab experiments were conducted with collaborators from the University of Minnesota using extramural funds to evaluate the use of novel nitrification inhibitors and soil amendments including biological material designed to improve crop nitrogen use efficiency. Additional lab experiments were conducted in collaboration with colleagues in Denmark using soils from Greenland. Results from these additional experiments are being analyzed and additional follow-up experiments are being planned.
Sub-objective 1c. Microbially produced volatile organic compounds (mVOC) can be used as an indicator of soil microbial processes. From the laboratory incubations completed to date, ARS scientists at Saint Paul, Minnesota, have observed a unique mVOC fingerprint that is correlated to the residue undergoing decomposition in laboratory incubations, but technical hurdles remain. One of the most significant is the vast complexity of the detected compounds (both in number and structural isomers). For most of these samples, fewer than 30% of the detected compounds were identified through the National Institute of Standards and Technology Library Search algorithm using commercially available software. Therefore, customized R-scripts were written to evaluate the collected mass spectra utilizing other online database options. The first linkage has been completed to the PubChem database (https://pubchem.ncbi.nlm.nih.gov). These scripts allow further compound identification and permit the evaluation of the spectral fitting by more sophisticated and diagnostic algorithms. This analysis has confirmed the number of identifiable mVOCs increased with the complexity of the substrate and with soil microbial biomass diversity. Work is currently on-going to link additional online databases that are specific to microbially produced compounds (i.e., mVOC2.0 - http://bioinformatics.charite.de/mvoc/). This linkage will permit more targeted compound identification and comparison with known species of bacteria and fungi that have been observed to produce identified compounds. A stable isotope mass spectrometer was purchased and recently installed within the Saint Paul, Minnesota, location which will be used for improved tracing of carbon cycling, which is particularly envisioned to aid LTAR research efforts, and more generally to improve mechanistic-level research for nitrogen cycling.
Sub-objective 2a. The field experiment examining improved nitrogen management practices through the use of soil additives was expanded and continued using extramural funds from Eurochem Agro. The fourth year of the overall study was successfully completed at three field sites including an experiment with corn in Saint Paul, Minnesota, and two experiments in Becker, Minnesota, one with corn and one with potato. The data have been analyzed and two manuscripts are being prepared. It is expected that at least one of these manuscripts will be submitted in FY20. The study found small agronomic benefits from soil additives that were not consistent across growing seasons. However, one of the additive combinations, 3,4-Dimethylpyrazole-succinic acid and N-(n-butyl) thiophosphoric acid triamide (DMPSA+NBPT), resulted in significant changes in soil nitrogen availability and reductions in the movement of nitrate below the root zone and the emission of nitrous oxide to the atmosphere. In a separate effort in collaboration with colleagues from Denmark and New Zealand, a method that uses diffusion modelling combined with statistical Monte Carlo analysis was developed to evaluate and compare the performance of different gas-flux calculation techniques used to determine fluxes of nitrous oxide and other gases from soils. The analysis was incorporated into a manuscript that was accepted for publication in the Journal of Environmental Quality. As part of this effort, a spreadsheet-based tool was developed to allow users to conduct their own analysis using site-specific inputs. In a separate effort, the effectiveness of a commercially available product containing nitrogen-producing microbes was evaluated for its impact on corn production and losses of reactive nitrogen to the environment. A field experiment using PROVEN™ was started in the spring 2020 and is continuing through to harvest in October. The automated flux chamber system for semi-continuous measurement of greenhouse gas fluxes is still undergoing repairs and testing. A permanent technician hired in June 2020 is reconfiguring the hardware and software components of the system and making several improvements that will be useful in coming years.
Sub-objective 2b. The manuscript on the column leaching experiment to evaluate losses of nitrogen (N) and phosphorus (P) from manure and non-manure sources on a range of soils is still in the peer-review process. Additional field experiments (five site-years) were conducted that were designed to determine N and P release from snow melt following dairy manure application under, within, or atop the snow-pack. Lab analyses of samples from this experiment are being completed. The data are expected to yield separate manuscripts on the N and P losses. The experiments will also provide data for model development and extend earlier laboratory work that described nutrient release to water over expected range of temperatures in Minnesota. The work is being done in collaboration with an ARS scientist in Marshfield, Wisconsin, and a manure research/extension expert at the University of Minnesota.
Accomplishments
1. International guidelines for chamber measurement of soil N2O emissions. Chamber measurements of nitrous oxide (N2O) emissions from agricultural soils provide the basis for greenhouse gas budgets at site, regional, national, and global scales and for validation of emissions models. While easy to adopt, chamber methods used by researchers across the world have varied with respect to several details which can lead to challenges in comparing results between studies and assessing their uncertainty. To improve the uniformity and reliability of these protocols, an ARS scientist in Saint Paul, Minnesota, collaborated with an international team of scientists in conjunction with the Global Research Alliance on Agricultural Greenhouse Gases (GRA) to develop and publish an updated set of methodological guidelines in a special section of the Journal of Environmental Quality. The guidelines address a comprehensive set of topics including chamber design and deployment, sample collection, storage and analysis, automated chambers, flux calculations, statistical analysis, emission factor estimation, reporting, modelling and backfilling approaches, and health and safety considerations, and will provide the basis for improved agricultural N2O emissions estimates gathered by researchers across the world working in both crop and livestock systems.
2. Tillage intensity and timing affect nitrogen availability in a living mulch system. Kura clover living mulch (KCLM) is a production system with several potential advantages for use in organic corn production, but optimum tillage strategies with KCLM have not been determined. ARS researchers in Saint Paul, Minnesota, evaluated four tillage regimes: no-till, strip-till, rotary zone tillage, and double-till (a combination of strip till and rotary zone tillage) in a two-year experiment in Rosemount, Minnesota, to determine their impact on soil nitrogen (N) mineralization and availability to corn grown with KCLM. Results showed that the amount of soil inorganic N in the root zone was a strong function of tillage intensity, with the greatest amount found in the double-tilled system. A large difference between years was also noted in all systems due to later planting the second year, which resulted in greater clover biomass and correspondingly greater soil N later in the season. These findings will promote the use of KCLM to increase N use efficiency, decrease fertilizer inputs, and reduce reactive N losses with organic and conventional corn production.
3. Biochar improves allelopathic chemical persistence. Allelopathic chemicals such as coumarin are known to have positive or negative effects on plant and microbial communities, but the influence of biochar on the fate of soil allelopathic chemicals is not understood. For the first time, ARS researchers in Saint Paul, Minnesota, studied the effects of biochar on coumarin by comparing its activity in unamended soil to its activity in soil amended with fresh and aged biochar. At high application rates, biochar increased the sorption of coumarin and, consequently, changed its degradation and leaching patterns. Results indicated that the increase in organic matter provided by the biochar was the dominant factor controlling coumarin sorption, and that alteration of biochar surface chemistry due to aging was not an important factor. These results have significant implications for the use of biochar as a soil amendment for enhancing the activity of naturally occurring allelochemicals.
Review Publications
Toczydlowski, A., Slesak, R., Kolka, R., Venterea, R.T. 2020. Temperature and water-level effects on greenhouse gas fluxes from black ash (Fraxinus nigra) wetlands in the Upper Great Lakes region, USA. Applied Soil Ecology. 153:103565. https://doi.org/10.1016/j.apsoil.2020.103565.
Venterea, R.T., Coulter, J., Clough, T. 2020. Nitrite accumulation and nitrogen gas production increase with decreasing temperature in urea-mended soils: Experiments and modeling. Soil Biology and Biochemistry. 142:107727. https://doi.org/10.1016/j.soilbio.2020.107727.
Toczydlowski, A., Slesak, R., Kolka, R., Venterea, R.T., D'Amato, A., Palik, B. 2019. Effect of simulated emerald ash borer infestation on nitrogen cycling in black ash (Fraxinus nigra) wetlands in northern Minnesota, USA. Forest Ecology and Management. 458:117769. https://doi.org/10.1016/j.foreco.2019.117769.
Alexander, J.R., Baker, J.M., Venterea, R.T., Coulter, J.A. 2019. Kura clover living mulch reduces fertilizer N requirements and increases profitablility of maize. Agronomy. 9(8):432. https://doi.org/10.3390/agronomy9080432.
Anderson, E., Jang, J., Venterea, R.T., Feyereisen, G.W., Ishii, S. 2020. Isolation and characterization of denitrifiers from woodchip bioreactors for bioaugmentation application. Journal of Applied Microbiology. https://doi.org/10.1111/jam.14655.
Chen, Z., Griffis, T.J., Baker, J.M., Millet, D.B., Wood, J.D., Dlugokencky, E.J., Andrews, A.E., Hu, C., Kolka, R.K. 2018. Source partitioning of methane emissions and its seasonality in the U.S. Midwest. Journal of Geophysical Research-Biogeosciences. 123(2):646-659. https://doi.org/10.1002/2017JG004356.
Souza, E.F., Soratto, R.P., Sandana, P., Venterea, R.T., Rosen, C. 2020. Split application of stabilized ammonium nitrate improved potato yield and nitrogen-use efficiency with reduced application rate in tropical sandy soils. Field Crops Research. 254. https://doi.org/10.1016/j.fcr.2020.107847.
Spiegal, S.A., Kleinman, P.J., Endale, D.M., Bryant, R.B., Dell, C.J., Goslee, S.C., Meinen, R.J., Flynn, K.C., Baker, J.M., Browning, D.M., McCarty, G.W., Bittman, S., Carter, J.D., Cavigelli, M.A., Duncan, E.W., Gowda, P.H., Li, X., Ponce, G., Raj, C., Silveira, M., Smith, D.R., Arthur, D.K., Yang, Q. 2020. Manuresheds: Advancing nutrient recycling in US agriculture. Agricultural Systems. 182:102813. https://doi.org/10.1016/j.agsy.2020.102813.
Yu, X., Millet, D.B., Wells, K.C., Griffis, T.J., Chen, X., Baker, J.M., Conley, S.A., Smith, M.L., Gvakharia, A., Kort, E.A., Plant, G., Wood, J.D. 2019. Top-down constraints on methane point source emissions from animal agriculture and waste based on new airborne measurements in the U.S. Upper Midwest. Journal of Geophysical Research-Biogeosciences. 125(1). https://doi.org/10.1029/2019JG005429.
Christianson, L.E., Feyereisen, G.W., Hay, C.H., Tschirner, U.W., Keegan, K.J., Soupir, M.L., Hoover, N.L. 2020. Denitrifying bioreactor woodchip recharge: Media properties after nine years. Transactions of the ASABE. 63(2):407-416. https://doi.org/10.13031/trans.13709.
Domingues, R.R., Sanchez-Monedero, M.A., Spokas, K.A., Melo, L.C., Trugilho, P.F., Valenciano, M.N., Silva, C.A. 2020. Enhancing cation exchange capacity of weathered soils using biochar: feedstock, pyrolysis conditions and addition rate. Agronomy. 10(6):824. https://doi.org/10.3390/agronomy10060824.
Deventer, J.M., Griffis, T.J., Roman, T.J., Kolka, R.B., Wood, J.D., Erickson, M.D., Baker, J.M., Millet, D.B. 2019. Error characterization of methane fluxes and budgets derived from a long-term comparison of open- and closed-path eddy covariance systems. Agricultural and Forest Meteorology. 278:107638. https://doi.org/10.1016/j.agrformet.2019.107638.
Ferraz-Almeida, R., Spokas, K.A., De Oliveira, R.C. 2020. Columns and detectors recommended in gas chromatography to measure greenhouse emission and O2 uptake in soil: A review. Communications in Soil Science and Plant Analysis. 51(5):582-594. https://doi.org/10.1080/00103624.2020.1729370.
Ginakes, P., Grossman, J., Baker, J.M., Sooksa-nguan, T. 2019. Tillage intensity influences nitrogen cycling in organic kura clover living mulch. Nutrient Cycling in Agroecosystems. 116:71-82. https://doi.org/10.1007/s10705-019-10025-0.
Griffis, T.J., Hu, C., Baker, J.M., Wood, J.D., Millet, D.B., Erickson, M.D., Yu, Z., Deventer, J.M., Winker, C.D., Chen, Z. 2019. Tall tower ammonia observations and emission estimates in the U.S. Midwest. Journal of Geophysical Research-Biogeosciences. 124(11):3432-3447. https://doi.org/10.1029/2019JG005172.
Gamiz, B., Velarde, P., Spokas, K.A., Cox, L. 2019. Dynamic effect of fresh and aged biochar on the behavior of the herbicide mesotrione in soils. Journal of Agricultural and Food Chemistry. 67(34):9450-9459. https://doi.org/10.1021/acs.jafc.9b02618.
Gamiz, B., Hall, K., Spokas, K.A., Cox, L. 2019. Understanding activation effects on low-temperature biochar for optimization of herbicide sorption. Agronomy. 9(10):588. https://doi.org/10.3390/agronomy9100588.
Novak, J.M., Spokas, K.A., Johnson, M.G. 2018. Concentration and release of phosphorus and potassium from lignocellulosic and manure-based biochars from fertilizer reuse. Frontiers in Sustainable Food Systems. https://doi.org/10.3389/fsufs.2018.00054.
De Klein, C.A., Harvey, M.J., Clough, T.J., Petersen, S.O., Chadwick, D.R., Venterea, R.T. 2020. Global Research Alliance N2O chamber methodology guidelines: Introduction, with health and safety considerations. Journal of Environmental Quality. 49(5):1073-1080. https://doi.org/10.1002/jeq2.20131.
Venterea, R.T., Petersen, S., de Klein, C., Pederson, A.R., Noble, A., Rees, R., Gamble, J.D., Parkin, T.B. 2020. Global research alliance N2O chamber methodology guidelines: Flux calculations. Journal of Environmental Quality. 49(5):1141-1155. https://doi.org/10.1002/jeq2.20118.
