Dairy farm water quality trends at AB Lime

Abstract

AIM The aim of this project is to conduct water quality analyses at AB Lime dairy farm by exploring the five years’ worth of water quality data along with the current data collected. The data will then be used to identify seasonal trends and discuss the impacts of current dairy farm practises to these trends. These finding will then be used to recommend strategies of sustainable dairy farm practices.

ABSTRACT Water quality monitoring is an essential way to help sustain lands. This is particularly important in dairy farms where constant inputs of excess nutrients on the soil and water affects the aquatic environment. This research analyses five years’ worth of previously collected water quality data, along with current data from a recently converted cut-and-carry land to a dairy farm at AB Lime Ltd, located in Winton. AB Lime’s unique location gives a great opportunity to carry out water quality testing and analysing as all the surface water can be attributed to the dairy farm since it is situated at the very top of a catchment. The data comes from water samples that were taken from identified nine sites where surface water and tile drains exit the farm. AB Lime follows the Standard Operating Procedure (SOP) for monthly dairy farm water sampling to ensure water quality samples were taken and sent to the Hill Laboratories correctly. The researcher adhered to these guidelines throughout the data collection. Seasonal trends of water parameters and biological parameters have been identified: Winter to Spring will see concentration of nitrates increase in the water exiting the farm. E. coli concentrations tend to proliferate in dry summer periods associated with higher water temperatures, attributing to more favourable conditions for regrowth. Similarly, Total Ammoniacal Nitrogen (TAN) concentration tends to intensify when weather is dry with high temperatures. No general seasonal trend has been associated with DRP concentration; however, it was found that the lower the concentration the severe the effect in the aquatic environment, stimulating algal growth in the water which can be toxic for livestocks, while rainfall events contribute to level of turbidity. The knowledge gained from this study allows the AB Lime’s staff to help the farmers understand the importance of water quality monitoring in order to make decisions around dairy farm practices for better water quality as well as giving recommendations of strategies on the farm. It is important that the AB Lime farm continues to monitor long-term water quality in order to provide swift mitigations on factors that could be degrading the water. Following the lead of AB Lime, it would be advantageous for all farms to undergo consistent water quality monitoring, especially given that Farm Environmental Management Plans (an important part of the consenting process for farms) require that farms shows good management practices around the discharge of contaminants to surface water.