Beef production often gets labeled as unsustainable partly because of its large water footprint. Estimates of the water used to produce one pound of beef are 1,675 gallons compared with 545 gallons to produce one pound of pork and 257 gallons to produce one pound of poultry. However, not all water has the same importance when it comes to sustainability. There are primarily 3 types of water used in the livestock production chain: green, blue and gray water. Green water is rainwater that landed on the field or pasture that required no human intervention to use. Blue water is primarily irrigation water for crops and drinking water for animals. Gray water is water used for cleaning animal facilities, processing plants, etc.
From a water sustainability perspective, blue and gray water are more important than green water because they involve removing water from its natural cycle, and blue and gray water could be used directly by humans. When we compare the water footprint of animal protein sources based on water type, it becomes clear that the important water footprint of beef is much more like poultry and pork (Figure 1). Over 90% of the water footprint for beef production is green water compared with 73% for pork and 79% for poultry. The blue and gray water footprint of beef is 158 gallons per pound compared with 146 gallons per pound for pork and 55 gallons per pound for poultry.
For all species of livestock, the vast majority (> 85%) of water use is to produce feed and the important type of water is blue water used to irrigate crops. Advances in irrigation technology and drought resistant crop varieties will further reduce blue water use for feed production. For example, subsurface drip irrigation can reduce irrigation water use by 45% and variable rate irrigation adjusts the amount of water applied to each square foot of the field based on soil characteristics and plant water needs. Also, in 2016, 40% of corn acreage in Nebraska and Kansas was planted to drought tolerant varieties.
When looking at the water types agriculture can control (blue and gray water), animal proteins are very similar in their water footprints. And technological advances in feed crop production will continue to reduce the blue water footprint of animal proteins.