Efficacy Of Best Management Practices Research Articles

Evaluating the Efficacy of Best Management Practices in Mitigating Sediment Yield and Nutrient Losses in the Lower Sutlej River Basin, India

Evaluating the Efficacy of Best Management Practices in Mitigating Sediment Yield and Nutrient Losses in the Lower Sutlej River Basin, India

PSV-1 Pasture Does Not Impact Pork Quality of Finishing Hogs

Abstract Sales of certified organic pork continue to increase, and an increasing number of young farmers are looking to rear hogs with organic or other niche labeling claims that require outdoor access. There is limited research available to support pastured pork operations in developing best management practices for rearing pigs in outdoor environments. The goal of this study was to evaluate the impact of housing on swine performance and pork quality and to build best management strategies for raising hogs on pasture. Pigs (n = 50) from the same sire and farrowing cohort were obtained from 10 separate litters. Pigs were grouped into separate treatments according to average body weights (BW) with equal sex rations among both groups: Indoor (n = 25), and Outdoor (n = 25), with 5 hogs per pen within each treatment. The Indoor groups were housed on 7m2 of solid concrete flooring in a ventilation-controlled barn; the Outdoor groups were housed on native grass pasture with pen size being 23m2, and a third shaded with 40% shade cloth. Outdoor pens were rotated to new grass every 14 days to manage soil destruction, while Indoor pigs remained in original pens for the duration of the project. Water access was provided via a nipple drinker system and fed a standard grow-finish ration ad libitum for both groups. All pigs were slaughtered at 26 weeks of age, with the Indoor group averaging BW of 126kg, and the Outdoor group averaging BW of 111kg (P < 0.05). Hot carcass weights were also larger (P < 0.001) of the Indoor group. All pork quality measurements were taken at the 10th rib. Color and marbling scores were not shown to vary between the treatment groups (P ≥ 0.17). Colorimeter values (L*, A*, B*) were similar across treatments as well (P ≥ 0.41). However, loin eye area exhibited a trend with the Outdoor group having a smaller average size (P = 0.07) In addition to this, pH values were also shown to vary at 0h (P = 0.03), 6h (P = 0.01), and 24h (P < 0.01) postmortem, with the Indoor group having the higher ultimate pH. Based on these data, pasture reduced final market size and loin eye area of hogs, but not overall pork quality. Although pH was reduced for the Outdoor group, no values showed a rapid decline in pH that would indicate a PSE pork product. Further, average pH between treatments were within 0.2 at all sampling times. Further research is needed to evaluate efficacy of best management practices to improve efficiency of pig growth rate on pasture and to ensure that pork quality will not be reduced.

Understanding farmers’ conservation behavior over time: A longitudinal application of the transtheoretical model of behavior change

Global waterbodies are experiencing increased risk of eutrophication and harmful algal blooms due to excess nutrients including phosphorus and nitrogen discharged from human activity on the landscape and as a result of climate change. Despite modeling that suggests the efficacy of best management practices in agricultural systems to be sufficient to address the problem, adoption by farmers remains far below the levels needed to achieve significant water quality improvements and new approaches to encourage and sustain adoption are urgently needed. In this work, we apply a modified transtheoretical model (TTM) of behavior change to a longitudinal dataset (N = 584) of farmers’ adoption decisions and stated intentions to use cover crops, collected in the Maumee Basin of Lake Erie, USA in 2016 and 2018. The TTM posits that behavior changes over time and is influenced by different social-psychological processes at each stage of change. Our findings confirm past research into the importance of many of the factors investigated, while providing new insight into their role in specific stages of the change process with potential implications for the design of interventions for farmers in different stages. Several factors investigated (mean environmental concern, education, information from conservation groups and off-farm income) were uniquely important to a particular stage. Other factors (response efficacy at the field level, total farm size and risks of spring planting interference) were important at both an earlier and later stage, but less important in predicting middle stages of change. A third set of factors (self-efficacy, proportion rented, no-till adoption and uncertain long-term paybacks) were statistically important across each stage of the TTM model. In applying the TTM longitudinally, we found evidence that farmers in a more advanced stage of cover crop adoption, in the first wave of data collection (2016) were more likely to have adopted cover crops in the second wave (2018), a result not predicted by individual factors alone. We report findings for cover crops but see the potential for the transtheoretical model of behavior change to be applied to other best management practice adoption decisions and to diverse populations of farmers to generate similarly novel insight and utility for intervention design and targeting.

Surface and subsurface phosphorus export from agricultural fields during peak flow events over the nongrowing season in regions with cool, temperate climates

In cool temperate regions with significant winter periods, midwinter thaws and the spring freshet are critical periods for annual phosphorus (P) loss from agricultural fields. The efficacy of best management practices during the winter period is not clear. This paper reports hydrologic and biogeochemical P losses in surface runoff and tile drainage from two fields in Ontario, Canada, during peak flow events (~5 per site) occurring throughout the nongrowing season (October to April). We relate inter-event variability in the quantity and speciation (dissolved or particulate) of P to event climatic drivers (e.g., rainfall, rain-on-snow, and snowmelt) and pre-event soil conditions (e.g., presence or absence of snow cover or presence of frozen ground). Runoff and P (dissolved and particulate) were lost via both surface and subsurface (tile) pathways; however, P concentrations were greater and more variable in surface runoff than in tile drain effluent. The total P load leaving the sites with both overland runoff and tile drainage during the October through April period observed ranged from 0.23 to 0.34 kg ha⁻¹ (0.21 to 0.30 lb ac⁻¹). Particulate P concentrations, particularly in surface runoff, increased as the proportion of precipitation that fell as rainfall increased, and flow-weighted mean concentrations of particulate P were greatest when rain fell on thawed, bare soils. Particulate P represented between 70% and 90% of the total P loss in the observation period. In contrast, while dissolved reactive P loads were only 10% to 30% of the total P loss, dissolved reactive P concentrations were greatest in January and declined over the remainder of the season. This work provides insight for the design and implementation of suitable best management practices for the mitigation of P losses throughout the nongrowing season.

Evaluating rain gardens as a method to reduce the impact of sewer overflows in sources of drinking water

The implications of climate change and changing precipitation patterns need to be investigated to evaluate mitigation measures for source water protection. Potential solutions need first to be evaluated under present climate conditions to determine their utility as climate change adaptation strategies. An urban drainage network receiving both stormwater and wastewater was studied to evaluate potential solutions to reduce the impact of combined sewer overflows (CSOs) in a drinking water source. A detailed hydraulic model was applied to the drainage basin to model the implementation of best management practices at a drainage basin scale. The model was calibrated and validated with field data of CSO flows for seven events from a survey conducted in 2009 and 2010. Rain gardens were evaluated for their reduction of volumes of water entering the drainage network and of CSOs. Scenarios with different levels of implementation were considered and evaluated. Of the total impervious area within the basin directly connected to the sewer system, a maximum of 21% could be alternately directed towards rain gardens. The runoff reductions for the entire catchment ranged from 12.7% to 19.4% depending on the event considered. The maximum discharged volume reduction ranged from 13% to 62% and the maximum peak flow rate reduction ranged from 7% to 56%. Of concern is that in-sewer sediment resuspension is an important process to consider with regard to the efficacy of best management practices aimed at reducing extreme loads and concentrations. Rain gardens were less effective for large events, which are of greater importance for drinking water sources. These practices could increase peak instantaneous loads as a result of greater in-sewer resuspension during large events. Multiple interventions would be required to achieve the objectives of reducing the number, total volumes and peak contaminant loads of overflows upstream of drinking water intakes.

Bioassessment of silvicultural impacts in streams and wetlands of the Eastern United States

Bioassessment is a useful tool to determine the impact of logging practices on the biological integrity of streams and wetlands. Measuring biota directly has an intuitive appeal for impact assessment, and biota can be superior indicators to physical or chemical characteristics because they can reflect cumulative impacts over time. Logging can affect stream and wetland biota by increasing sedimentation rates, altering hydrologic, thermal, and chemical regimes, and changing the base of food webs. Biotic impacts of logging on streams compared to wetlands probably differ, and in this paper we review some of those differences. In streams, invertebrates, fishes, amphibians, algae, and macrophytes have been used as indicators of logging impacts. In wetlands, bioassessment is just beginning to be used, and plants and birds are the most promising indicator taxa. Various best management practices (BMPs) have been developed to reduce the impacts of logging on stream and wetland biota, and we review quantitative studies that have evaluated the efficacy of some of these techniques in streams and wetlands in the eastern United States. Remarkably few studies that address the overall efficacy of BMPs in limiting biotic changes in streams and wetlands after BMP implementation have been published in scientific journals, although some work exists in reports or is unpublished. We review these works, and compile conclusions about BMP efficacy for biota from this body of research.