Aqualinc: Impact of dairy farming on water quantity and quality

Different farm systems that are in use internationally put varying degrees of pressure on water resources and the quality of receiving waters.

A team of researchers from Aqualinc, along with collaborators from Nepal and the Netherlands, have recently published a paper “Impacts of dairy farming systems on water quantity and quality in Brazil, Ethiopia, Nepal, New Zealand and the USA” in the Journal of Irrigation and Drainage.

Their research examined the performance of dairy farming systems in Brazil, Ethiopia, Nepal, New Zealand, and the USA, based on existing databases of the Food and Agriculture Organization of the United Nations, and country‐specific data sources.

The research team explains that there are primarily three types of dairy farming, with pasture‐based open grazing being the dominant one in Brazil and New Zealand.

In the USA, stall‐feeding is more popular, while mixed dairy farming is traditionally adopted in Ethiopia and Nepal.

Lead author Dr Birendra KC, a Civil and Environmental Engineer with Aqualinc, says compared to the mixed and pasture‐based systems, the stall‐feeding system puts more pressure on water quantity, as the water requirement to produce a given amount of concentrated feed required for a stall‐feeding system is higher than to produce an equivalent amount of grass, crop residue, and fodder required for pasture‐based and mixed systems.

“Nitrate leaching, and subsequent contamination of water resources, is the biggest environmental problem,” says Birendra, “the high‐intensity stall‐feeding in USA, followed by the pasture‐based system in New Zealand, are the most challenging in terms of managing nutrient losses.”

Birendra says that well-controlled irrigation systems and irrigation scheduling that considers water availability, soil moisture, and plant growth stages are important for mitigating the impacts of dairy farming, particularly where conversion from low-production land to a higher production system is being considered.

Read the research

KC, B., Schultz, B., McIndoe, I., Rutter, H., Dark, A., Prasad, K., Sijapati, S. & Paudel, K. (2020). Impacts of dairy farming systems on water quantity and quality in Brazil, Ethiopia, Nepal, New Zealand and the USA. Irrig. and Drain. https://doi.org/10.1002/ird.2486.

Find out more about Aqualinc.