Water quality in the surficial aquifer near agricultural areas in the Delaware Coastal Plain, 2014

Fleming, Brandon J.; Mensch, Laura L.; Denver, Judith M.; Cruz, Roberto M.; Nardi, Mark R.

doi:10.3133/sir20175054

Cited by 2 publications

(1 citation statement)

References 14 publications

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“…Surplus nitrogen inputs to cropland increased from 1985 through 2020 in the Upper Chester River watershed, likely because of increasing poultry populations (Figure S4B) and crop production (Figure S5). Possibly in response to these activities, groundwater concentrations of dissolved nitrogen increased throughout the Delmarva Peninsula in recent decades (Fleming et al., 2017; Lindsey & Rupert, 2012) and NO x concentrations in Chesterville Branch were higher since 2011 than the early 1990s and 2000s (Figure S12). Although NO x delivered by groundwater to Chesterville Branch can be decades old (Hyer et al., 2016), the stable trends in TN load monitored in recent years may, in part, reflect the chemistry of stormwater runoff.…”

Section: Nutrient and Sediment Responses And Driversmentioning

confidence: 99%

Evaluating water‐quality trends in agricultural watersheds prioritized for management‐practice implementation

Webber,

Chanat,

Clune

et al. 2024

J American Water Resour Assoc

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Many agricultural watersheds rely on the voluntary use of management practices (MPs) to reduce nonpoint source nutrient and sediment loads; however, the water‐quality effects of MPs are uncertain. We interpreted water‐quality responses from as early as 1985 through 2020 in three agricultural Chesapeake Bay watersheds that were prioritized for MP implementation, namely, the Smith Creek (Virginia), Upper Chester River (Maryland), and Conewago Creek (Pennsylvania) watersheds. We synthesized patterns in MPs, climate, land use, and nutrient inputs to better understand factors affecting nutrient and sediment loads. Relations between MPs and expected water‐quality improvements were not consistently identifiable. The number of MPs increased in all watersheds since the early 2010s, but most monitored nutrient and sediment loads did not decrease. Nutrient and sediment loads increased or remained stable in Smith Creek and the Upper Chester River. Sediment loads and some nutrient loads decreased in Conewago Creek. In Smith Creek, a 36‐year time‐series model suggests that changes in manure affected flow‐normalized total nitrogen loads. We hypothesize that increases in nutrient applications may overshadow some expected MP effects. MPs might have stemmed further water‐quality degradation, but improvements in nutrient loads may rely on reducing manure and fertilizer applications. Our results highlight the importance of assessing MP performance with long‐term monitoring‐based studies.

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Section: Nutrient and Sediment Responses And Driversmentioning

confidence: 99%