Evaluation of cattle bedding and grazing BMPs in an agricultural watershed in Alberta

2011 ◽  
Vol 64 (2) ◽  
pp. 326-333 ◽  
Author(s):  
Barry M. Olson ◽  
Andrea R. Kalischuk ◽  
Janna P. Casson ◽  
Colleen A. Phelan

This paper highlights the environmental impacts of implementing beneficial management practices to address cattle bedding and direct access to the creek in a study watershed in southern Alberta, Canada. Approximately 35 cow–calf pairs grazed 194 ha of grass forage and had direct access to the creek in the spring and summer. During winter, the cattle were fed adjacent to the creek at an old bedding site. The practice changes included off-stream watering, bedding site relocation and fencing for rotational grazing. The cost was $15,225 and 60 h of labour. Four years of data were used in a before-and-after experimental design to evaluate the practice changes. After two years of post-implementation monitoring, riparian assessments showed an increase in plant diversity, but no change in the percent cover of the riparian species Salix exigua and Juncus balitus and a decrease in Carex sp. (P < 0.05). Water quality monitoring showed a decrease in the difference between upstream and downstream concentrations of total phosphorus, total dissolved phosphorus, total nitrogen, organic nitrogen and Escherichia coli (P < 0.10). These results showed that improved environmental changes in riparian and water quality can be measured following the implementation of beneficial management practices for cattle bedding and grazing.

1993 ◽  
Vol 28 (3-5) ◽  
pp. 379-387 ◽  
Author(s):  
S. Mostaghimi ◽  
P. W. McClellan ◽  
R. A. Cooke

The Nomini Creek Watershed/Water Quality monitoring project was initiated in 1985, as part of the Chesapeake Bay Agreement of 1983, to quantify the impacts of agricultural best management practices (BMPs) on improving water quality. The watershed monitoring system was designed to provide a comprehensive assessment of the quality of surface and groundwater as influenced by changes in land use, agronomic, and cultural practices in the watershed over the duration of the project. The primary chemical characteristics monitored include both soluble and sediment-bound nutrients and pesticides in surface and groundwater. Water samples from 8 monitoring wells located in agricultural areas in the watershed were analyzed for 22 pesticides. A total of 20 pesticides have been detected in water samples collected. Atrazine is the most frequently detected pesticide. Detected concentrations of atrazine ranged from 0.03 - 25.56 ppb and occurred in about 26 percent of the samples. Other pesticides were detected at frequencies ranging from 1.6 to 14.2 percent of all samples collected and concentrations between 0.01 and 41.89 ppb. The observed concentrations and spatial distributions of pesticide contamination of groundwater are compared to land use and cropping patterns. Results indicate that BMPs are quite effective in reducing pesticide concentrations in groundwater.


2019 ◽  
Vol 43 (2) ◽  
pp. 240-255 ◽  
Author(s):  
Neill Barr ◽  
John Zeldis ◽  
Kristin Scheuer ◽  
David Schiel

AbstractTogether, macroalgal tissue biochemical nitrogen indices (N-indices) and macroalgal abundance can be used as bioindicators of N-enrichment in estuaries. In this study, we examine the extent and rates of response of Ulva bioindicators during rapid N-enrichment perturbations in the eutrophic Avon-Heathcote Estuary (AHE) (Christchurch, New Zealand). With the diversion of the city’s wastewater discharge away from the estuary in March 2010, a ~ 90% reduction in the estuary’s N-concentration was expected. In turn, this was expected to reduce macroalgal biomass and improve the overall trophic condition of the estuary. We surveyed Ulva bioindicators over a five-year period spanning the diversion. There was a rapid (within one year) transition away from eutrophic condition reflected in N-indices (tissue-chlorophyll, -free amino acids, -N and -δ15N) following wastewater diversion, towards values corresponding with ‘cleaner’ water quality. This was accompanied by large reductions in Ulva percent cover, based on seasonal surveys conducted from 2001 to 2014. However, two large earthquakes in February and June 2011 caused a breakdown of the city’s wastewater infrastructure, resulting in overflows of untreated sewage into the estuary between February and November 2011. The re-enrichment of N and changes in N-sources (treated versus untreated sewage) were rapidly reflected in Ulva bioindicators, notably δ15N. Following repair of infrastructure, Ulva bioindicators again reverted towards a less eutrophic state. Overall, bioindicators were sensitive to changes in N-availability and N-source, and useful for identifying the position of algal populations on a eutrophic-to-oligotrophic gradient. These attributes demonstrated their utility as adjuncts to water quality monitoring and algal biomass surveys.


Land ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 977
Author(s):  
Yogesh P. Khare ◽  
Rajendra Paudel ◽  
Ruscena Wiederholt ◽  
Anteneh Z. Abiy ◽  
Thomas Van Lent ◽  
...  

Soil phosphorus (P) built up due to past management practices, legacy P, in the Lake Okeechobee Watershed (LOW) in south-central Florida, U.S.A., is often discussed as the root cause of lake eutrophication. Improvement of the lake’s water quality requires the identification of critical P sources and quantifying their contributions. We performed a global sensitivity analysis of the Watershed Assessment Model (WAM), a common evaluation tool in LOW environmental planning, using the Morris method. A pre-calibrated WAM setup (Baseline) of the LOW sub-watershed, Taylor Creek Nubbin Slough (TCNS), was used as a test case. Eight scenarios were formulated to estimate the contributions of various P sources. The Morris analysis indicated that total phosphorus (TP) loads were highly sensitive to legacy P in improved pastures, the major land use covering 46.2% of TCNS. The scenario modeling revealed that legacy P, inorganic fertilizers, and other sources contribute 63%, 10%, and 32%, respectively, to the Baseline TP load of 111.3 metric tons/y to the lake. Improved pastures, dairies, citrus, and field crops are the top TP load contributors. Our results have important implications for water quality improvement plans in the LOW and highlighted the need for accurate spatial mapping of legacy P and incorporation of such information in modeling efforts for watersheds demonstrating legacy P problems.


Sign in / Sign up

Export Citation Format

Share Document