Nutrient and sediment runoff from agricultural landscapes with varying suites of conservation practices in the Mississippi Alluvial Valley

Baker, Beth H.; Czarnecki, Joby M. Prince; Omer, A.R.; Aldridge, Caleb A.; Kröger, R.; Prevost, John

doi:10.2489/jswc.73.1.75

Cited by 23 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…At both sites, the hydrologic characteristics of the flow events were highly variable with some flow statistics varying by two or more orders of magnitude (table 3). The hydrologic characteristics and variability found in BLT1 and LWSR are consistent with findings of other research on agricultural ditches in Mississippi (Baker et al 2018;Littlejohn et al 2014).…”

Section: Methodssupporting

confidence: 90%

“…The mixed results presented here are consistent with other studies in agricultural drainages in the MAP, as well as other intensive agricultural areas with BMPs. Some studies have shown decreases in sediment (Lizotte et al 2014;Corsi et al 2005), P (Bishop et al 2005;Baker et al 2016;Littejohn et al 2014), and N (Corsi et al 2005;Littlejohn et al 2014), while other studies have shown little to no reduction in sediment or nutrient (Lizotte et al 2017;Baker et al 2018;Corsi et al 2012).…”

Section: Potential Changes Between Early and Late Periodsmentioning

confidence: 99%

“…Variability in crop type and soil type can greatly affect sediment and nutrient concentrations and loads (Aryal and Reba 2017). Variability in hydrology and crop production practices can make detecting changes in nutrients and sediment challenging (Baker et al 2018). Rainfall frequency, duration, and intensity vary within and between years, also contributing to seasonal and annual variability in concentrations and loads (Sharpley et al 2015).…”

Section: Potential Changes Between Early and Late Periodsmentioning

confidence: 99%

See 2 more Smart Citations

Assessing water quality changes in agricultural drainages: Examples from oxbow lake tributaries in northwestern Mississippi, United States, and simulation-based power analyses

Murphy¹,

Hicks²,

Stocks³

2020

Journal of Soil and Water Conservation

View full text Add to dashboard Cite

Hydrology (streamflow and stage) and water quality (suspended sediment, total nitrogen [N], ammonia [NH 3 ], total Kjeldahl N, nitrate plus nitrite [NO 3 + NO 2 ], and total phosphorus [TP]) were monitored in two small agricultural drainages in northwestern Mississippi to document changes in water quality that coincided with the implementation of best management practices (BMPs) in upstream drainages. Using an event-based data set and bootstrapping techniques, we tested for difference and equivalence in median event concentration and differences in concentration-streamflow (C-Q) relationships between an early and late period at each site, where most of the major BMP implementation occurred during the early period. Results for Bee Lake Tributary were inconclusive. Using 95% confidence intervals, none of the constituents were statistically different or equivalent for median event concentrations between the periods, indicating a lack of evidence to determine whether water quality had changed or stayed the same, and only TP had a significantly higher C-Q intercept during the late period. At Lake Washington Tributary, more than half the constituents had a significantly different median, slope, or intercept between periods, indicating a 35% or more decrease in event concentration following a period of intense BMP implementation. These mixed results could be due to a variety of differences between the sites including the type and timing of BMP implementation, production practices, and crop types. We also used the monitoring data to generate synthetic data and performed a simulation-based power analysis to explore the ability to detect change under 25 scenarios of sampled event counts and hypothetical percentage changes. The simulation-based power analysis indicated that natural variability in event concentration and flow hindered our ability to detect change. The results from this study can be used to guide future decisions pertaining to monitoring efforts in small agricultural drainage basins in the Mississippi Alluvial Plain.

show abstract

Section: Methodssupporting

confidence: 90%

Section: Potential Changes Between Early and Late Periodsmentioning

confidence: 99%

Section: Potential Changes Between Early and Late Periodsmentioning

confidence: 99%

See 1 more Smart Citation

Assessing water quality changes in agricultural drainages: Examples from oxbow lake tributaries in northwestern Mississippi, United States, and simulation-based power analyses

Murphy¹,

Hicks²,

Stocks³

2020

Journal of Soil and Water Conservation

View full text Add to dashboard Cite

show abstract

“…In response to this threat, regulatory agencies in the United States and Europe have tasked water resource managers with developing numeric criteria for nutrients that protect the physical, chemical, and biological integrity of aquatic ecosystems (USEPA, 1998; Hering et al, 2006). In addition to regulatory limit setting, a substantial amount of federal, state, and private funding has been invested in testing and implementing best management practices (BMPs) that reduce nonpoint‐source nutrient runoff from agricultural fields (Baker et al, 2018). Thus, the agricultural community and resource managers also need defensible ecological measures to demonstrate water quality improvements in watersheds with BMP implementation.…”

mentioning

confidence: 99%

Diatom Assemblage Changes in Agricultural Alluvial Plain Streams and Application for Nutrient Management

Hicks¹,

Taylor

2019

J of Env Quality

View full text Add to dashboard Cite

In large, alluvial floodplains dominated by agriculture, small streams have the potential to experience nutrient enrichment affecting algal assemblage structure and metabolism. Nutrient enrichment is largely driven by application of nutrients and altered hydrologic regimes. To inform stressor–response‐based nutrient reduction goals for agricultural alluvial plain streams, diatom assemblages were sampled from 25 streams located within the Mississippi Alluvial Plain (MAP) with various land management practices and associated P and N inputs. From August through September 2015, epidendric diatom assemblage samples were collected from instream woody debris. Field nutrient gradients were skewed toward higher concentrations, and ranges of previously reported diatom assemblage response thresholds indicative of oligotrophic conditions were not well represented. Ordination analysis identified a gradient in species composition associated with increasing P and decreasing dissolved oxygen. A significant shift in diatom assemblage structure occurred when total P concentrations in the MAP streams exceeded 0.12 mg L−1. Phosphorus‐enriched systems were represented by a distinct set of indicator species, lower abundances of ubiquitous species, greater abundances of highly tolerant species, and greater abundances of high‐P indicator species. No relationships were observed among diatom assemblage measures or traits with increasing N. Current results do not address potential criteria for identifying high‐quality, oligotrophic streams. However, measures of diatom assemblage structure have potential for helping set benchmarks to reduce nutrient impacts and monitor effects of agricultural best management practices on MAP streams. Core Ideas Identifying stream nutrient indicators is difficult in agricultural landscapes. Diatoms found in Mississippi Alluvial Plain streams are sensitive to changes in P concentrations. Diatom assemblages shifted when stream total P concentrations exceeded ∼0.12 mg L−1. Diatom measures can help set nutrient reduction goals for agricultural streams. Stream diatom indicators may improve monitoring success of nutrient best management practices.

show abstract

“…Suites of CPs do not always lead to water quality improvement, as demonstrated by Baker et al (2018). Failure of CP suites to address P losses may be due to the lack of redundancy in the system, inability of practices to reduce P, transformation of P, or a multitude of issues surrounding CP implementation and water quality monitoring.…”

Section: Implementing Conservation Practice Systemsmentioning

confidence: 99%

Increasing the Effectiveness and Adoption of Agricultural Phosphorus Management Strategies to Minimize Water Quality Impairment

Osmond

Shober²,

Sharpley

et al. 2019

J of Env Quality

View full text Add to dashboard Cite

Phosphorus (P) is essential for optimum agricultural production, but it also causes water quality degradation when lost through erosion (sediment‐attached P), runoff (soluble reactive P; SRP), or leaching (sediment‐attached P or SRP). Implementation of conservation practices (CP) affects P at the source (avoiding), during transport (controlling), or at the water resource edge (trapping). Trade‐offs often occur with CP implementation. For instance, multiple researchers have shown that conservation tillage reduces total P by over 50%, while increasing SRP by upward of 40%. Conservation tillage may increase water quality degradation as SRP is more bioavailable than is particulate P. Conservation practices must be implemented as a system of practices to increase redundancy and to address all loss pathways, such as P management with conservation tillage and a riparian buffer. Further, planning and adoption must be at a watershed scale to ensure practices are placed in critical source areas, thereby providing the most treatment for the least price. Farmers must be involved in watershed planning, which should include financial backstopping and educational outreach. It is imperative that CPs be used more effectively to reduce and retard off‐site P losses. New and innovative CPs are needed to improve control of P leaching, address legacy stores of soil test P, and mitigate increased P losses expected with climate change. Without immediate changes to CP implementation, P losses will increase due to climate change, with a concomitant degradation of water quality. These changes must be made at a watershed scale and in an intentional and transparent manner. Core Ideas Phosphorus‐reducing conservation practices must control all P pathways. Phosphorus‐reducing conservation practices must be utilized as systems. New and innovative conservation practices are needed to improve control of P. Farmer decision‐making must be considered when implementing conservation practices. Watershed planning and conservation practice implementation must be intentional.

show abstract

Nutrient and sediment runoff from agricultural landscapes with varying suites of conservation practices in the Mississippi Alluvial Valley

Cited by 23 publications

References 0 publications

Assessing water quality changes in agricultural drainages: Examples from oxbow lake tributaries in northwestern Mississippi, United States, and simulation-based power analyses

Assessing water quality changes in agricultural drainages: Examples from oxbow lake tributaries in northwestern Mississippi, United States, and simulation-based power analyses

Diatom Assemblage Changes in Agricultural Alluvial Plain Streams and Application for Nutrient Management

Increasing the Effectiveness and Adoption of Agricultural Phosphorus Management Strategies to Minimize Water Quality Impairment

Contact Info

Product

Resources

About