Suite Of Best Management Practices Research Articles

Evaluating nitrate and phosphorus remediation in intensively irrigated stream-aquifer systems using a coupled flow and reactive transport model

In irrigated semi-arid watersheds, over-fertilization often leads to nitrogen (N) and phosphorus (P) contamination in aquifers and river systems. Modelling tools often are used to evaluate the effect of management practices on nutrient contamination levels. In this study, we assess a suite of best management practices (BMPs) for N and P in a regional irrigated stream-aquifer system using a new numerical model. As it is necessary to consider the interaction of flow in the stream and aquifer, SWAT-MODFLOW model that couples surface and groundwater flow was used. The reactive processes were modelled using RT3D that simulate the reactive groundwater transport. The model is based on the coupled flow model SWAT-MODFLOW, with the groundwater reactive transport model RT3D included to simulate the reactive groundwater transport of NO3 and soluble P and their interactions within the soil-aquifer-stream system. The assessment is performed for a highly managed 732 km2 region in the Lower Arkansas River Valley (south-eastern Colorado), with model results compared to observed groundwater nutrient concentration, in-stream nutrient concentration and loading, and crop yield. A total of 28 BMPs scenarios are evaluated regarding their impact on NO3 and soluble P contamination in the aquifer and river system. The most effective individual BMP in most areas is to decrease fertilizer by 30%, resulting in NO3 and soluble P reduced by 20% and 2% for groundwater concentrations, 25% and 10% for river concentrations, and 27% and 6% for mass loadings into surface water, respectively. Combinations of using 30% irrigation reduction, 30% fertilization reduction, 60% canal seepage reduction, and conservation tillage yield the greatest overall impact to lower NO3 and soluble P concentrations up to 41% and 8% in groundwater, 52% and 40% in river, and 63% and 49% for mass loadings. Targeting BMPs on localized problem areas shows great promise in reducing contamination while maintaining region-wide crop yield. The study demonstrates the SWAT-MODFLOW-RT3D modelling code is a useful tool to examine NO3 and P transport and quantify BMP effects in groundwater-driven watersheds.

Communicating the 4Rs to farmers: Insights and opportunities

P lant nutrients are essential to the food, feed, fiber, and fuel supply. Additionally, plant nutrients, no matter the form, can be lost from the plant root zone as water moves through the system. In recent decades, plant nutrients have become the focus of concerns linked to water quality, air quality, greenhouse gas emissions, and supply chain sustainability. For on farm productivity and profitability, as well as the concerns listed above, a common goal is to reduce nutrient movement from the root zone and to further reduce loss from the cropping system with supporting conservation practices. Through significant outreach, education, and engagement, the fertilizer industry and other stakeholders have created significant awareness of 4R nutrient stewardship. The 4Rs are a suite of best management practices linked to the right nutrient source, applied at the right rate, the right time, and in the right place (Lawrence et al. 2014). While practices such as cover crops, conservation tillage, and drainage water management can be instrumental in retaining applied nutrients within the crop production system, the 4Rs are a key place to start. Survey data indicate that while the use of 4R practices is on the rise, opportunities for improvement remain. Practice adoption in…

Analysis of soil management and water conservation practices adoption among crop and pasture farmers in humid-south of the United States

Nutrient management, water quality protection, and irrigation efficiency top the list of on-farm resource concerns indicating a need to address them through conservation strategies. A suite of Best Management Practices (BMPs) has been identified and recommended, through several outlets, to farmers to ameliorate these concerns. This research examines the adoption of strategies that ameliorate the resource concerns as a joint decision, using a bivariate model. Data from the 2016 Nutrient Management Survey, conducted by the Louisiana Master Farmer Program, are used to examine the factors affecting adoption of these conservation practices. A bivariate probit regression found significant results for explanatory variables and emphasize the effect of perception regarding the role of on-farm practices, ownership of land, participation in conservation programs in the past, and producers educational attainment on the likelihood of adopting the conservation practices. Implications for policy development and educational programs are discussed.

Lake Nutrient Responses to Integrated Conservation Practices in an Agricultural Watershed.

Watershed-scale management efforts to reduce nutrient loads and improve the conservation of lakes in agricultural watersheds require effective integration of a variety of agricultural conservation best management practices (BMPs). This paper documents watershed-scale assessments of the influence of multiple integrated BMPs on oxbow lake nutrient concentrations in a 625-ha watershed of intensive row-crop agricultural activity during a 14-yr monitoring period (1996-2009). A suite of BMPs within fields and at field edges throughout the watershed and enrollment of 87 ha into the Conservation Reserve Program (CRP) were implemented from 1995 to 2006. Total phosphorus (TP), soluble reactive phosphorus (SRP), ammonium, and nitrate were measured approximately biweekly from 1996 to 2009, and total nitrogen (TN) was measured from 2001 to 2009. Decreases in several lake nutrient concentrations occurred after BMP implementation. Reductions in TP lake concentrations were associated with vegetative buffers and rainfall. No consistent patterns of changes in TN or SRP lake concentrations were observed. Reductions in ammonium lake concentrations were associated with conservation tillage and CRP. Reductions in nitrate lake concentrations were associated with vegetative buffers. Watershed simulations conducted with the AnnAGNPS (Annualized Agricultural Non-Point Source) model with and without BMPs also show a clear reduction in TN and TP loads to the lake after the implementation of BMPs. These results provide direct evidence of how watershed-wide BMPs assist in reducing nutrient loading in aquatic ecosystems and promote a more viable and sustainable lake ecosystem.

Stormwater runoff to an impaired lake: impacts and solutions.

Stormwater runoff can represent a significant source of pollutants to downstream water bodies. An integrated assessment was conducted for the Spring Lake watershed in western Michigan because of concerns that increased impervious land cover in the watershed, especially in sub-basins adjacent to Spring Lake, would result in greater stormwater runoff and pollutant loads. Spring Lake has a history of high total phosphorus (TP) concentrations and cyanobacterial blooms. An alum treatment, paid for by an assessment, was applied to Spring Lake in 2005 to control internal phosphorus loading; hence, there was an economic incentive for stakeholders to limit new phosphorus from entering the lake, which otherwise would reduce the long-term efficacy of the alum treatment. This study provides a novel six-step process that identifies priority areas and optimally reduces nonpoint sources of pollution. We identified a suite of best management practices to be placed in the watershed, assessed their optimal locations based on pollutant sources, and modeled the degree to which their implementation would reduce TP and total suspended solids. Application of the modeled best management practices (BMPs) resulted in a 15 % reduction in TP load and a 17 % reduction in total suspended solid load. Reductions were not uniform throughout the watershed, with the greatest reductions closest to Spring Lake. We also developed a flow chart for BMP selection, which may be transferable to other watersheds with similar issues.

A study of cattle producer preferences for best management practices in an East Tennessee watershed

Best Management Practices (BMPs) contribute to a broader range of efforts to improve the environmental performance of the livestock sector and its impact on water quality. This research evaluates a survey of cattle producers in an East Tennessee watershed and parts of five surrounding watersheds, along with and the factors correlated with preferences for BMPs designed to reduce sediment, nutrient, and fecal coliform contamination of surface waters by limiting cattle access to streams. The objective of the survey was to gather behavioral information about producer interest in specific BMPs in an effort to supplement a long-term biophysical modeling project. Structures and BMPs analyzed include stream crossings, rotational grazing, pasture improvement, and cattle water tanks. The physical and economic constraints faced by producers and the incentives provided by state and federal programs influence the decision to adopt a set of practices or structures that impact pathogen loading into streams. There was a clear preference for a suite of BMPs that did not include stream crossings, reinforcing anecdotal evidence that the maintenance associated with frequent high flow events may reduce willingness to install stream crossings. Cattle producers were more willing to implement rotational grazing and pasture improvement BMPs, which were associated with cattle health and productivity. The extensive distribution of pastureland in the region analyzed, the relatively inexpensive costs of adopting practices supporting pasture improvement, and higher quality forage correlated with improved pastures suggest a win-win outcome for cattle owners and efforts to enhance water quality.

An analysis of urban forest management plans in Canada: Implications for urban forest management

Urban forests are an integral part of urban ecosystems and quality of city life. The urban forest in Canada is highly valued, underscoring the importance of devising schemes for sustainable urban forest management. During the last decade, many urban forest management plans (UFMPs) have been prepared. This study analyses 14 Canadian UFMPs published in this period. We found that most of the UFMPs are dominated by an approach that relies on single-tree maintenance, canopy-cover enhancement, tree-diversity enhancement, and planting-oriented educational programmes. These activities dominate the operational features of the plans, while other ecological, social, and economic considerations lack specificity and operational clarity. A suite of best management practices based on UFMP documentation is included here.

Implementation of BMP Strategies for Adaptation to Climate Change and Land Use Change in a Pasture-Dominated Watershed

Implementing a suite of best management practices (BMPs) can reduce non-point source (NPS) pollutants from various land use activities. Watershed models are generally used to evaluate the effectiveness of BMP performance in improving water quality as the basis for watershed management recommendations. This study evaluates 171 management practice combinations that incorporate nutrient management, vegetated filter strips (VFS) and grazing management for their performances in improving water quality in a pasture-dominated watershed with dynamic land use changes during 1992–2007 by using the Soil and Water Assessment Tool (SWAT). These selected BMPs were further examined with future climate conditions (2010–2069) downscaled from three general circulation models (GCMs) for understanding how climate change may impact BMP performance. Simulation results indicate that total nitrogen (TN) and total phosphorus (TP) losses increase with increasing litter application rates. Alum-treated litter applications resulted in greater TN losses, and fewer TP losses than the losses from untreated poultry litter applications. For the same litter application rates, sediment and TP losses are greater for summer applications than fall and spring applications, while TN losses are greater for fall applications. Overgrazing management resulted in the greatest sediment and phosphorus losses, and VFS is the most influential management practice in reducing pollutant losses. Simulations also indicate that climate change impacts TSS losses the most, resulting in a larger magnitude of TSS losses. However, the performance of selected BMPs in reducing TN and TP losses was more stable in future climate change conditions than in the BMP performance in the historical climate condition. We recommend that selection of BMPs to reduce TSS losses should be a priority concern when multiple uses of BMPs that benefit nutrient reductions are considered in a watershed. Therefore, the BMP combination of spring litter application, optimum grazing management and filter strip with a VFS ratio of 42 could be a promising alternative for use in mitigating future climate change.

Modeling watershed-scale effectiveness of agricultural best management practices to reduce phosphorus loading

Planners advocate best management practices (BMPs) to reduce loss of sediment and nutrients in agricultural areas. However, the scientific community lacks tools that use readily available data to investigate the relationships between BMPs and their spatial locations and water quality. In rural, humid regions where runoff is associated with saturation-excess processes from variable source areas (VSAs), BMPs are potentially most effective when they are located in areas that produce the majority of the runoff. Thus, two critical elements necessary to predict the water quality impact of BMPs include correct identification of VSAs and accurate predictions of nutrient reduction due to particular BMPs. The objective of this research was to determine the effectiveness of BMPs using the Variable Source Loading Function (VSLF) model, which captures the spatial and temporal evolutions of VSAs in the landscape. Data from a long-term monitoring campaign on a 164-ha farm in the New York City source watersheds in the Catskills Mountains of New York state were used to evaluate the effectiveness of a range of BMPs. The data spanned an 11-year period over which a suite of BMPs, including a nutrient management plan, riparian buffers, filter strips and fencing, was installed to reduce phosphorus (P) loading. Despite its simplicity, VSLF predicted the spatial distribution of runoff producing areas well. Dissolved P reductions were simulated well by using calibrated reduction factors for various BMPs in the VSLF model. Total P losses decreased only after cattle crossings were installed in the creek. The results demonstrated that BMPs, when sited with respect to VSAs, reduce P loss from agricultural watersheds, providing useful information for targeted water quality management.

A sinkhole filter for protection of karst groundwater

Protection of groundwater quality in karst regions presents land and resource managers with special challenges. About one-quarter of the world's water supply comes from karst sources. Forty percent of the United States east of Tulsa, Oklahoma, is karst. A disproportionately high amount of agricultural production occurs on the fertile karst soils of the Appalachian region. Contaminants such as sediment, nitrate, and pathogens rapidly reach the shallow groundwater in Appalachian karst through the region's extensive network of sinkholes and sinking streams. The sinkholes often provide direct entry points to the underground system of caves and conduits that rapidly move water and contaminants great distances in a short time. The intimate relation between surface processes and groundwater requires a suite of best management practices tailored to site-specific settings to effectively protect groundwater resources in karst areas.