Julie Weitzman

All Publications

• Geochemical and sediment dynamics during an experimental high flow pulse event on the Allegheny River: Lessons for river system management BIOGEOCHEMISTRY Elliott, E. M., Sinon, H., Yancy, A. J., Butkus, C. R., Zuccolotto, G., Weitzman, J. N., Bain, D. J., Oezpolat, E., Ayo-Bali, A., Zidar, K., Whitmire, S. L. 2025; 168 (4)

  View details for DOI 10.1007/s10533-025-01243-6

  View details for Web of Science ID 001514389200001

• A Liposomal Carrier to Reduce Leaching of Ionic Nutrient Loads in Agricultural Soils. Environmental science & technology Dunn, P. J., Mohammadzadeh, A., Pamuru, S. T., Butkus, C. R., Weitzman, J. N., Tian, Q., Yonet Tanyeri, N., Dalton, L. E., Elliott, E. M., Little, S. R., Gilbertson, L. M. 2025

  Abstract

  The use of inorganic nutrient fertilizers in crop agriculture is often inefficient due to rapid leaching of nutrients with percolating water in soil. To address this, a liposomal carrier was developed to slow transport and reduce leaching of inorganic nutrient loads within agricultural soils. Liposomes, spherical lipid bilayers, have been widely used in medicine but remain under-characterized for agricultural applications. Their biocompatibility, high loading capacity, and stability under certain compositions and environmental conditions suggest they could effectively deliver agrochemicals to crops. We present soil column experiments to evaluate the ability of a liposomal carrier to reduce the transport of an ionic tracer load, sodium bromide, under varying soil and water saturation conditions. Results from saturated column experiments demonstrate that encapsulation in liposomes slowed tracer transport and reduced leachate concentrations in sand and silty clay loam soils. Reduction in tracer leachate was also observed for unsaturated column experiments in silty clay loam soil. Subsequent experiments suggested a combination of processes (i.e., attachment, aggregation, physical exclusion, and biogenic immobilization) were responsible for the observed behavior of liposome encapsulated tracer in the soil column experiments. These findings support the use of liposomes as an effective carrier of inorganic nutrients to reduce leaching.

  View details for DOI 10.1021/acs.est.4c14370

  View details for PubMedID 40459328

• Vadose zone flushing of fertilizer tracked by isotopes of water and nitrate VADOSE ZONE JOURNAL Weitzman, J. N., Brooks, J., Compton, J. E., Faulkner, B. R., Peachey, R., Rugh, W. D., Coulombe, R. A., Hatteberg, B., Hutchins, S. R. 2024

  View details for DOI 10.1002/vzj2.20324

  View details for Web of Science ID 001198382400001

• Unearthing a stream-wetland floodplain system: increased denitrification and nitrate retention at a legacy sediment removal restoration site, Big Spring Run, PA, USA BIOGEOCHEMISTRY Forshay, K. J., Weitzman, J. N., Wilhelm, J. F., Hartranft, J., Merritts, D. J., Rahnis, M. A., Walter, R. C., Mayer, P. M. 2022; 161 (2): 171-191

  View details for DOI 10.1007/s10533-022-00975-z

  View details for Web of Science ID 000863138400001

• Deep soil nitrogen storage slows nitrate leaching through the vadose zone AGRICULTURE ECOSYSTEMS & ENVIRONMENT Weitzman, J. N., Brooks, J., Compton, J. E., Faulkner, B. R., Mayer, P. M., Peachey, R. E., Rugh, W. D., Coulombe, R. A., Hatteberg, B., Hutchins, S. R. 2022; 332: 1-13

  Abstract

  Nitrogen (N) fertilizer applications are important for agricultural yield, yet not all the applied N is taken up by crops, leading to surplus N storage in soil or leaching to groundwater and surface water. Leaching loss of fertilizer N represents a cost for farmers and has consequences for human health and the environment, especially in the southern Willamette Valley, Oregon, USA, where groundwater nitrate contamination is prevalent. While improved nutrient management and conservation practices have been implemented to minimize leaching, nitrate levels in groundwater continue to increase in many long-term monitoring wells. To elucidate controls on leaching rates and N dynamics in agricultural soils across soil depths, and in response to seasonal and annual variation in management (e.g., fertilizer input amount and summer irrigation), we intensively monitored the transport of water and nitrate every two weeks for four years through the vadose zone at three depths (0.8, 1.5, and 3.0 m) in a sweet corn (maize) field. Though nitrate leaching was highly variable among lysimeters at the same depth and across years, a strong pattern emerged: annual nitrate leaching significantly decreased with depth across the study, averaging ~104 kg N ha-1 yr-1 near the surface (0.8 m) versus ~56 kg N ha-1 yr-1 in the deep soil (3.0 m), a 54% reduction in leaching between the soil layers. Even though crops were irrigated in summer, most leaching (~72% below 3.0 m) occurred during the wet fall and winter. Based on steady state assumptions, a net equivalent of ~29% of surface N inputs leached below 3.0 m into the deeper soil and groundwater, while ~44% was removed in crop harvest, indicating considerable N retention in the soil (~27% of inputs or approximately 58 kg N ha-1 yr-1). The accumulation and long-term dynamics of deep soil N is a legacy of agricultural management that should be further studied to better manage and reduce nitrate loss to groundwater.

  View details for DOI 10.1016/j.agee.2022.107949

  View details for Web of Science ID 000791946900003

  View details for PubMedID 35400773

  View details for PubMedCentralID PMC8988158

• Drivers of Hot Spots and Hot Moments of Denitrification in Agricultural Systems JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Weitzman, J. N., Groffman, P. M., Adler, P. R., Dell, C. J., Johnson, F. E., Lerch, R. N., Strickland, T. C. 2021; 126 (7)

  View details for DOI 10.1029/2020JG006234

  View details for Web of Science ID 000677821700004

• Coupling the dual isotopes of water (<i>δ</i><SUP>2</SUP>H and <i>δ</i><SUP>18</SUP>O) and nitrate (<i>δ</i><SUP>15</SUP>N and <i>δ</i><SUP>18</SUP>O): a new framework for classifying current and legacy groundwater pollution ENVIRONMENTAL RESEARCH LETTERS Weitzman, J. N., Brooks, J., Mayer, P. M., Rugh, W. D., Compton, J. E. 2021; 16 (4): 1-45008

  Abstract

  Nitrate contamination of groundwater is a concern globally, particularly in agricultural regions where decades of fertilizer nitrogen (N) use has led to a legacy of N accumulation in soils and groundwater. Linkages between current management practices and groundwater nitrate dynamics are often confounded by the legacy effect, and other processes unrelated to management. A coupled analysis of dual stable isotopes of water (δH2O = δ2H and δ18O) and nitrate (δNO3 - = δ15N and δ18O) can be a powerful approach to identify sources and processes responsible for groundwater pollution. To assess how management practices impact groundwater nitrate, we interpreted behavior of δH2O and δNO3 -, together with nitrate concentrations, in water samples collected from long-term monitoring wells in the Southern Willamette Valley (SWV), Oregon. The source(s) of nitrate and water varied among wells, suggesting that the nitrate concentration patterns were not uniform across the shallow aquifer of the valley. Analyzing the stability versus variability of a well's corresponding δH2O and δNO3 - values over time revealed the mechanisms controlling nitrate concentrations. Wells with stable δH2O and δNO3 - values and nitrate concentrations were influenced by one water source with a long residence time and one nitrate source. Variable nitrate concentrations of other wells were attributed to dilution with an alternate water source, mixing of two nitrate sources, or variances in the release of legacy N from overlying soils. Denitrification was not an important process influencing well nitrate dynamics. Understanding the drivers of nitrate dynamics and interaction with legacy N is crucial for managing water quality improvement. This case study illustrates when and where such coupled stable isotope approaches might provide key insights to management on groundwater nitrate contamination issues.

  View details for DOI 10.1088/1748-9326/abdcef

  View details for Web of Science ID 000632374100001

  View details for PubMedID 33897808

  View details for PubMedCentralID PMC8059602

• Ecosystem Nitrogen Response to a Simulated Ice Storm in a Northern Hardwood Forest ECOSYSTEMS Weitzman, J. N., Groffman, P. M., Campbell, J. L., Driscoll, C. T., Fahey, R. T., Fahey, T. J., Schaberg, P. G., Rustad, L. E. 2020; 23 (6): 1186-1205

  View details for DOI 10.1007/s10021-019-00463-w

  View details for Web of Science ID 000497871500001

• Susquehanna Shale Hills Critical Zone Observatory: Shale Hills in the Context of Shaver's Creek Watershed VADOSE ZONE JOURNAL Brantley, S. L., White, T., West, N., Williams, J. Z., Forsythe, B., Shapich, D., Kaye, J., Lin, H., Shi, Y., Kaye, M., Herndon, E., Davis, K. J., He, Y., Eissenstat, D., Weitzman, J., DiBiase, R., Li, L., Reed, W., Brubaker, K., Gu, X. 2018; 17 (1)

  View details for DOI 10.2136/vzj2018.04.0092

  View details for Web of Science ID 000450238100001

• Nitrogen Budget and Topographic Controls on Nitrous Oxide in a Shale-Based Watershed JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Weitzman, J. N., Kaye, J. P. 2018; 123 (6): 1888-1908

  View details for DOI 10.1029/2017JG004344

  View details for Web of Science ID 000438667200008

• Weathering of rock to regolith: The activity of deep roots in bedrock fractures GEODERMA Hasenmueller, E. A., Gu, X., Weitzman, J. N., Adams, T. S., Stinchcomb, G. E., Eissenstat, D. M., Drohan, P. J., Brantley, S. L., Kaye, J. P. 2017; 300: 11-31

  View details for DOI 10.1016/j.geoderma.2017.03.020

  View details for Web of Science ID 000402349200002

• Nitrate retention capacity of milldam-impacted legacy sediments and relict A horizon soils SOIL Weitzman, J. N., Kaye, J. P. 2017; 3 (2): 95-112

  View details for DOI 10.5194/soil-3-95-2017

  View details for Web of Science ID 000457191000002

• Variability in Soil Nitrogen Retention Across Forest, Urban, and Agricultural Land Uses ECOSYSTEMS Weitzman, J. N., Kaye, J. P. 2016; 19 (8): 1345-1361

  View details for DOI 10.1007/s10021-016-0007-x

  View details for Web of Science ID 000388928800002

• Potential nitrogen and carbon processing in a landscape rich in milldam legacy sediments BIOGEOCHEMISTRY Weitzman, J. N., Forshay, K. J., Kaye, J. P., Mayer, P. M., Koval, J. C., Walter, R. C. 2014; 120 (1-3): 337-357

  View details for DOI 10.1007/s10533-014-0003-1

  View details for Web of Science ID 000339871700021