Jarrod O. Miller
Associate Professor and Extension Specialist in Agronomy University of Delaware
- Newark DE
Prof. Miller is interested in how precision ag technologies can make farms more economically and environmentally efficient.
Media
Social
Biography
Industry Expertise
Areas of Expertise
Media Appearances
As land turns salty, farmers grapple with lost income
Maryland Matters online
2024-12-31
“I think we’re still at the point where we don’t know enough,” said Jarrod Miller, a soil expert and farming consultant, also at the University of Delaware. “I don’t have a grasp on what’s going to work here. On everything, we’re behind. On practices, we don’t know.”
Rising sea levels threatens farming along Chesapeake Bay
PBS NewsHour tv
2024-06-27
To help farmers get a handle on how their lands are changing, the University of Delaware's Jarrod Miller uses drones to photograph how crops are growing, and matches those with measurements of salinity in the soil.
Salt patches, a product of rising seas, are spreading rapidly on the Chesapeake’s Eastern Shore
Bay Journal online
2023-11-13
“It’s not like you lost half a field,” said Jarrod Miller, a soil expert at the University of Delaware. “It could have been just a foot along the edge of these fields. But when you add it up, it’s a lot of acreage across the region.”
‘Fighting for inches’ in the Southeast’s struggle with salt
Yale Climate Connections online
2022-09-23
“By the time you can visually see it, it’s too late in some cases,” added Dr. Jarrod Miller, assistant professor and extension specialist in agronomy at the University of Delaware. With tight windows on which to grow, harvest, and sell crops, farmers often can’t afford the margin of error that salinized fields bring.
Articles
Planting date effects on soybean yield and foliar nutrient concentrations across the Mid‐Atlantic region
Agronomy Journal2025
The effect of three planting dates on soybean (Glycine max L. Merr.) yield and foliar nutrient concentrations was evaluated across four sites representing the Coastal Plain, Piedmont, and Ridge and Valley regions of the Mid‐Atlantic. Group IV soybeans were planted at 2‐week intervals from mid‐April to late May. Trifoliate leaves and surface soils (0–15 cm) were sampled at the R2 stage. Although yield did not differ significantly among planting dates, several foliar nutrient concentrations were affected. Foliar K, Ca, S, and Fe declined with later planting, though all remained within sufficiency ranges. Only S showed parallel declines in both soil and tissue, suggesting a possible link between soil availability and plant uptake, though loss pathways and timing of availability should be further explored.
Evaluating routine agronomic soil tests for coastal soil salinity detection in the mid‐Atlantic
Soil Science Society of America Journal2025
Coastal salinity is a growing concern for managing agricultural soils in the eastern United States, including the Delmarva Peninsula. The saturated paste (SP) extraction, which is the standard method for measuring soil salinity in arid climates, is not widely available in the eastern United States and its effectiveness in humid coastal soils is unknown. We evaluated the Mehlich‐3 (M3) routine agronomic soil test as an alternative to SP and ammonium acetate (AA) extractions on samples from 13 Delmarva agricultural fields with known salinity issues. Soils were analyzed for electrical conductivity (EC) by SP extract (ECe) or deionized water (1:2 and 1:5 soil‐to‐water ratios; EC1:2 and EC1:5).
Understanding the yield impacts of alternative cover crop families and mixtures: Evidence from side‐by‐side plot‐level panel data
Agrosystems, Geosciences & Environment2024
The short‐run effects of cover crop use on cash crop yields (e.g., corn [Zea mays L.] and soybeans [Glycine max (L.) Merr.]) have been a topic of debate given that evidence from previous literature has generally been mixed on this issue. Past studies suggest that the observed yield effect varies (i.e., negative, positive, or insignificant), often depending on the applied cover crop species used, weather conditions, and farm management practices implemented (among others). In this study, we examine the short‐run (i.e., 1 year) yield impact of four different cover crop families—grasses (Poaceae), broadleaves (Brassicaceae), legumes (Fabaceae), and others—both as single‐family groups and as mixtures.
Management strategies for reducing phosphorus levels in saltwater-intruded agricultural fields
Agriculture, Ecosystems & Environment2024
As sea levels continue to rise and high tide flooding events increase in frequency, researchers and farmers alike are looking for solutions to adapt to and mitigate the effects of saltwater intrusion (SWI). Some landowners on the Lower Eastern Shore of Maryland respond to SWI by taking land out of agriculture. For example, they (1) attempt to remediate salt-damaged soils (e.g., planting switchgrass, Panicum virgatum), (2) restore native marsh grasses (e.g., planting saltmarsh hay, Spartina patens), or (3) abandon fields altogether (e.g., allow for natural recruitment). This work examines the ability of each of these land management practices to reduce phosphorus (P) levels in soils and porewater, with the overall goal to benefit both the farming community and water quality in the Chesapeake Bay.
Assessing relationships of cover crop biomass and nitrogen content to multispectral imagery
Agronomy Journal2024
Cover crops provide valuable roles in sustainable agriculture, provided they produce enough biomass. To accurately measure their services to field management, spatial estimates would be useful to producers. This study used multispectral drone imagery to produce maps of normalized difference vegetation index (NDVI), normalized difference red edge index (NDRE), and a digital surface model (DSM) of cover crop plots on sandy, Mid‐Atlantic soils. Cover crops included cereal rye (Secale cereale), mixtures of rye and crimson clover (Trifolium incarnatum), and mixtures of rye and hairy vetch (Vicia villosa). Their biomass was sampled in the spring of 2019, 2020, and 2021, dried, weighed, and analyzed for total nitrogen (N) content.
Research Grants
Evaluation of Cover Crop Timing, Soil Nitrate Availability, and Crop Emergence. Natural Resources Conservation Service Grant
NRCS DE Conservation Agreements for Implementing Key Conservation Objectives in Delaware
2018-2021
Accomplishments
Achievement Award: Communications, National Association of County Agricultural Agents
2016
Achievement Award: Communications, National Association of County Agricultural Agents
2015
Education
University of Kentucky
PhD
Soil Science
2008
Virginia Polytechnic Institute and State University
MS
Crop and Soil Environmental Science
2002
Virginia Polytechnic Institute and State University
BS
Environmental Science
1999
Affiliations
- American Society of Agronomy : Member
- Soil Science Society of America : Member
