113 Southern awareness and implementation of pasture best management practices

ABSTRACTOperational stream crossings on forest roads and skid trails are potential sediment delivery areas from timber harvests that can negatively affect water quality if best management practices (BMPs) are not sufficiently implemented. Virginia has three major physiographic regions (Mountains, Piedmont, Coastal Plain), and the diverse topographies require some specificity of BMP guidelines for water quality protection. Furthermore, truck roads and skid trails utilize different drainage and erosion control BMPs to maintain sufficient working conditions and access to timber. As a result, differing BMP approaches and implementation levels for roads and trails inherently have different associated costs. We evaluated BMP implementation levels on 154 stream crossing approaches (3 regions × 2 road types × a minimum of 25 stream crossings). We categorized the crossings as BMP− (failed to meet recommended BMPs), BMP-standard (met recommended guidelines), or BMP+ (exceeded recommended guidelines). We estimated hypothetical costs for elevating BMP− stream crossings to BMP-standard and BMP+ and costs of elevating BMP-standard to BMP+. Average BMP implementation audit scores for stream crossings were 88% on skid trails and 82% on truck roads. To upgrade from a BMP− to BMP-standard, the cost-benefit ratio ($/Mg of sediment prevented) averaged $248.58/Mg for skid trails and $670.33/Mg for truck roads. Enhancement from BMP-standard to BMP+ level is less economically efficient and BMP implementation efficacy at stream crossings appears to plateau at the BMP-standard level.

Nonpoint source transport of nutrients, sediment, and pathogens from agricultural activities is a major concern in the Ozark Highlands of Northwest Arkansas; rolling hills in this region are home to thousands of poultry farms and pastures that produce forage for numerous beef and dairy cattle, resulting in an abundance of animal manure. The predominant use of manure in the area has been as a fertilizer for perennial forage crops. There is growing concern that excess land applications of the manure can lead to surface and ground water pollution due to increased runoff losses of sediment, nutrients, and pathogens. Additionally, this region is experiencing a rapid urbanization resulting in the loss of forest and pasture lands and adding to existing concerns regarding nonpoint pollution. There has, however, been some best management practice (BMP) implementation in the area over the years, these mainly pertaining to nutrient and grazing management. This study seeks to quantify the effects of implementation, timing, and spatial distribution of the BMPs on sediment and nutrient loss reduction and watershed ecological integrity, with a focus on Lincoln Lake watershed, a primarily agricultural watershed in NW Arkansas. An analysis of historical land use and BMP implementation for this watershed showed a 9% increase in urban areas and an 11% decrease in pastured areas during the years 1992-2004. About 10% of the watershed was in a transitional land use, comprising newly cleared forests and abandoned pastures. Over the same time period, BMP implementation increased from <1% to 34% of the watershed area, extending across most of the pasture lands in the watershed. During this time, sediment and total phosphorus losses declined by 22% and 4% respectively, while total nitrogen losses increased by 11%, based on analyses of historical in-stream water quality data. Because of the overlap between BMP implementation and occurrence of land use changes, detailed modeling analyses were found necessary to help distinguish between the effects of BMPs and those due to land use changes. This paper discusses the assessment of BMP impacts based on historical data, as well as on preliminary modeling analyses using the Soil and Water Assessment Tool (SWAT).

ABSTRACT: To quantify the effectiveness of best management practice (BMP) implementation on runoff, sediment, and nutrient yields from a watershed, the Nomini Creek watershed and water quality monitoring project was initiated in 1985, in Westmoreland County, Virginia. The changes in nonpoint source (NPS) loadings resulting from BMPs were evaluated by comparing selected parameters from data series obtained before, during, and after periods of BMP implementation. The results indicated that the watershed‐averaged curve number, sediment, and nutrient (N and P) concentrations were reduced by approximately 5, 20, and 40 percent, respectively, due to BMP implementation. The nutrient yield model developed by Frere et al. (1980) was applied to the water quality parameters from 175 storms, but it failed to adequately describe the observed phenomena. Seasonal changes in nutrient availability factors were not consistent with field conditions, nor were they significantly different in the pm‐ and post‐BMP periods. An extended period of monitoring, with intensive BMP implementation over a larger portion of the watershed, is required to identify BMP effectiveness.

Analysis of daily phosphorus-yield and streamflow data collected before and after implementation of agricultural best-management practices in the Johnson Brook watershed in south-central Maine indicated statistically significant reductions in phosphorus loading in all flow categories. Reduction of median loadings for five flow categories ranged from 26 to 90 percent. The annual total phosphorus yield was reduced 17 percent after implementation of the best-management practices. The observed phosphorus yield reduction is considerable because of two streamflow factors. First, the period after implementation of the best-management practices had eight more storms. Periods of storm runoff in the postimplementation period had 31 days with greater average streamflow and a maximum daily streamflow more than three times greater than those observed in the preimplementation period. Second, the annual streamflow was 128 percent greater in the year after the management practices were implemented. Because the potential for phosphorous transport increases with runoff, and greater yields are possible when the volume of water increases, a higher phosphorous yield would be expected in the postimplementation period then during the preimplementation period, if other factors had remained unchanged. The reductions in phosphorous yield in the study area are not expected to have a significant effect on the eutrophic conditions observed in Lovejoy Pond. Phosphorous concentrations in the pond will continue to be capable of supporting algal blooms. However, the intensity and duration of blooms are expected to be less than those observed before best-management practice implementation. 1 Hydrologist, U.S. Geological Survey, Augusta, Maine 2 Biologist, Maine Department of Environmental Protection, Augusta, Maine

Forest residue utilization for energy has increased in the southeastern United States and additional increases are anticipated. However, such removals generate concerns regarding potential accelerated erosion and nutrient drains, which could affect site productivity and stream water quality. To address erosion and water quality concerns, postharvest erosion rates, operational feature areas, best management practice (BMP) implementation, residual ground cover, soil disturbance, and forest residue concentrations were evaluated on ten biomass and ten conventional clearcut harvests in Virginia’s Coastal Plain. No significant differences in erosion rates (P = 0.4727) were observed between biomass (0.71 tons ac-1 yr-1) and conventional (0.61 tons ac-1 yr-1) harvests. BMP compliance percentages were similar (P = 0.6776) for both biomass (88.54%) and conventional (90.99%) harvests. BMP implementation scores were determined to be a significant predictor of erosion rates (P &amp;lt; 0.0001). A significant reduction (28%) in postharvest residue concentrations was observed for biomass (10.22 tons ac-1) versus conventional harvests (14.24 tons ac-1) (P = 0.0173). Scores for BMP implementation and erosion rates were not significantly different between treatments, indicating that sufficient residual biomass exists for appropriate implementation of BMPs. BMPs provided similar erosion protection on both biomass and conventional clearcut harvests.Study Implications: Forest residues are widely used to cover and stabilize bare soil as best management practices (BMPs) for erosion control. The expanding bioenergy market has raised concerns that overutilization of forest residues may occur. Comparisons of biomass and conventional harvests in the Coastal Plain of Virginia revealed few significant postharvest differences. Implementation of existing water quality BMPs is important for minimizing erosion on biomass harvests; however, the development of biomass harvesting guidelines in addition to current state BMPs appears unnecessary under current harvesting practices. Harvest residue management should be conducted to ensure adequate supplies of woody debris remain for site protection.

There is growing interest in evaluating the impacts at the watershed scale of agricultural best management practices (BMPs) designed to improve water quality. Many approaches to impact assessment require detailed information about actual BMP use by farmers and landowners in a watershed. This paper examines the strengths and weaknesses of using formal USDA Natural Resources Conservation Service records of conservation program participation as an indicator of spatial and temporal patterns of BMP implementation and maintenance. Field interviews with conservation program participants revealed potential limitations with official records regarding (1) documentation of the incidence of successful BMP implementation, (2) the nature of the BMPs that were implemented, (3) accurate measurement of the timing and location of BMP implementations, and (4) information about the long-term use and maintenance of implemented BMPs. The results suggest that official records should be field-verified before being used as indicators of BMP use. The findings also point to a larger need for development of more robust and accurate systems for tracking BMP implementation and maintenance over periods of time.

Reducing surface water pollution through the assessment of the cost-effectiveness of BMPs at different spatial scales

ABSTRACT: Driven by increasing concerns about bacterial pollution from agricultural sources, states such as Virginia have initiated cost sharing programs that encourage the use of animal waste best management practices (BMPs) to control this pollution. Although a few studies have shown that waste management BMPs are effective at the field scale, their effectiveness at the watershed scale and over the long term is unknown. The focus of this research was to evaluate the effectiveness of BMPs in reducing bacterial pollution at the watershed scale and over the long term. To accomplish this goal, a 1,163 ha watershed located in the Piedmont region of Virginia was monitored over a ten‐year period. Fecal coliforms (FC) and fecal streptococci (FS) were measured as indicators of bacterial pollution. A pre‐BMP versus post‐BMP design was adopted. Major BMPs implemented were manure storage facilities, stream fencing, water troughs, and nutrient management. Seasonal Kendall trend analysis revealed a significant decreasing trend during the post‐BMP period for FC concentrations at the watershed outlet, but not at the subwatershed level. Implementation of BMPs also resulted in a significant reduction in the geometric mean of FS concentrations. FC concentrations in streamflow at the watershed outlet exceeded the Virginia primary standard 86 and 74 percent of the time during pre‐BMP and post‐BMP periods, respectively. Corresponding exceedances for the secondary standard were 50 and 41 percent. Violations decreased only slightly during the post‐BMP period. The findings of this study suggest that although BMP implementation can be expected to accomplish some improvement in water quality, BMP implementation alone may not ensure compliance with current water quality standards.

Major conventional and traditional public sanitation networks are out of date and have proven their limits to sustainably manage stormwater. Decentralized approach to stormwater management, whereby Best Management Practices (BMP) are dispersed throughout the site project, has gained popularity in recent years. Stormwater BMPs provide an actual, alternative and more sustainable approach than the conventional practice of routing runoff through pipe systems. The selection of the appropriate stormwater BMP to a site project requires experiences and a fine appreciation of many selection criteria. BMPs may be selected according to a wide range of criteria regarding the land use characteristics, the site characteristics, the catchment characteristics, the quantity and quality performance requirements and the amenity, environmental, community and participation requirements. This paper gives a BMP selection aid tool based on a literature review of many public space projects designed with stormwater BMPs. BMPs are classified according to the land use and their position in the stormwater management train. The classification of BMPs proposed in the tool, and based on actually built project, is then compared to the BMPs selection guidelines found in the literature. It appears that, related to land use criteria for the selection of the appropriate BMP, the implementation of BMPs in developed projects is poorly correlated to the guidelines of the literature.

Florida's unique combination of sub-tropical climate, sandy soils, high-value crops, and shallow water tables have made the development and implementation of best management practices (BMPs) to reduce environmental impacts from agricultural production a challenge. Most of the BMP development has followed commodity lines, with the primary programs developed to date in the following: citrus, sod, vegetables, equine, agronomic crops, cow calf operations, silviculture, container nurseries, forage grasses, aquaculture, and leatherleaf ferns. BMP programs have been developed for the golf course and landscape industries in addition to programs focused on lawn care, yards, and homeowners associations. Each of the BMP programs are designed to reduce impacts to ground and surface waters by reducing loadings of nutrients, pesticides, sediment, and flow volume running off the properties. This paper summarizes the BMP processes that have produced a BMP manuals, workshops, on-farm demonstrations, public education campaigns, and extensive agricultural worker training programs. This paper also presents lessons learned about developing consensus among the diverse interests involved in developing BMPs.

Urbanization result into more impervious land cover and increased stormwater runoff leads to flooding of the drainage system. Best Management Practice (BMP) is an alternative approach to manage the urban stormwater runoff at the source where it originates. BMPs like permeable pavement, infiltration trench, bioretention cell, rainwater barrel storage and so on will be used to reduce rate of flow and flow volume. The present paper describes a simulation modeling approach to incorporate such BMPs in an existing hydrological model to estimate the performance of each BMP on runoff volume reduction under different rainfall characteristics. The results obtained are according to the suitable BMPs site availability in the study area. The BMP results are validated with the international stormwater management BMP database and results are comparable. The results indicate that, permeable pavement, infiltration trench, and rainwater barrel storage BMP scenarios are more effective than bioretention cell BMP scenarios in flood volume reduction under heavier and shorter rainfall events. This study provides information on BMPs implementation and its performance which is essential for urban flooding mitigation in the study area.

Implementation of best management practices (BMPs), such as improved manure storage, buffer strips, and grassed waterways, through government funded conservation programs is a common approach for mitigation of the impacts agricultural activities have on the surrounding environment. In this study, we tested the ability of these practices to meet the environmental goal of improved stream quality at a “micro-basin” scale in the Upper Thames River Watershed, southern Ontario, Canada. Micro-basins were first and second order basins, averaging 400 ha in area, representing gradients of land cover, geomorphology, and participation in conservation programs. At the outflow of each micro-basin the benthic macro-invertebrate community was sampled, water chemistry measurements completed, and habitat quality assessed. Results showed micro-basins with relatively high levels of BMP implementation consistently demonstrated improved stream ecosystem quality over the majority of micro-basins with low or no implementation. Streams in the Upper Thames River basin appeared to exhibit a threshold effect, where with several BMPs in the same basin an improvement in stream ecosystem quality is visible. In addition to the BMPs implemented through government funded conservation programs, the observed ecosystem improvements are probably due to increased environmental awareness and improved management by farmers.

Agricultural best management practices for Conesus Lake: The role of extension and soil/water conservation districts

Excess nutrients and herbicides remain two major causes of waterbody impairment globally. In an attempt to better understand pollutant sources in the Big Sandy Creek Watershed (BSCW) and the prospects for successful remediation, a program was initiated to assist agricultural producers with the implementation of best management practices (BMPs). The objectives were to (1) simulate BMPs within hotspots to determine reductions in pollutant loads and (2) to determine if water-quality standards are met at the watershed outlet. Regression-based load estimator (LOADEST) was used for determining sediment, nutrient and atrazine loads, while artificial neural networks (ANN) were used for determining E. coli concentrations. With respect to reducing sediment, total nitrogen and total phosphorus loads at hotspots with individual BMPs, implementing grassed waterways resulted in average reductions of 97%, 53% and 65% respectively if implemented all over the hotspots. Although reducing atrazine application rate by 50% in all hotspots was the most effective BMP for reducing atrazine concentrations (21%) at the gauging station 06883940, this reduction was still six times higher than the target concentration. Similarly, with grassed waterways established in all hotspots, the 64% reduction in E. coli concentration was not enough to meet the target at the gauging station. With scaled-down acreage based on the proposed implementation plan, filter strip led to more pollutant reductions at the targeted hotspots. Overall, a combination of filter strip, grassed waterway and atrazine rate reduction will most likely yield measureable improvement both in the hotspots (&gt;20% reduction in sediment, total nitrogen and total phosphorus pollution) and at the gauging station. Despite the model’s uncertainties, the results showed a possibility of using Soil and Water Assessment Tool (SWAT) to assess the effectiveness of various BMPs in agricultural watersheds.

The effects of buffer strips and bioretention facilities on agricultural productivity and environmental quality in Central Africa