Sunday, May 3, 2015

Embracing Complexity

In California’s ongoing conversation about drought, we seem to look for simple answers to an incredibly complicated problem.  Lauren Michele’s piece (“Why knock almonds? Alfalfa uses more water) in the April 26, 2015 edition of California Forum is no exception – “Californians need to lay off the cheeseburgers, and the media needs to lay off the almonds,” Michele concludes.  In other words, California could solve its water crisis if we’d stop raising cattle and growing alfalfa.  But like most matters concerning water and agriculture, reality is far more complex than Michele would have us believe.

Michele begins her piece by citing oft repeated – and incorrect – “data” regarding the water required to produce beef.  In California, beef cattle spend the majority of their lives on rangeland – land that by definition is not  irrigated.  Much of this water, then, is rainfall that grows grass – not irrigation water.  Those of us who rely on grasslands watered by rainfall have faced “reductions” in our water supply each of the last four years – simply because we didn’t receive our normal precipitation.  In general terms, we've only grown two-thirds of our normal grass this year.  Most of us have adjusted by selling livestock.

Much of California’s water originates on or flows across rangeland that is used for sheep and cattle production.  Grazing, as a land use, is an important factor in maintaining habitat diversity and connectivity, in managing invasive species (like yellow starthistle), and in reducing wildfire threat.  Eliminate rangeland livestock production and we lose these critical ecosystem services.

Alfalfa, from an economic standpoint, may indeed contribute less value to California’s economy than almonds.  From an environmental perspective however, alfalfa is an important crop.  It is often grown in long-term rotation with other crops; as a legume, it naturally fixes nitrogen in the soil, which reduces the need for fertilizer applications.  When alfalfa is irrigated, the water that is not taken up by the plant helps recharge groundwater supplies or flows back to surface water where it can be used for agricultural or environmental benefit downstream.

In the meantime, we have been planting almonds and other permanent crops on rangelands that were not previously irrigated.  Technological and cultural advancements have made it possible to grow (and irrigate) crops on land that could only grow grass in years past.  As Michele suggests, these decisions are largely economic – an unirrigated acre of grass provides a net return of $1.02 to a rancher, while an acre of irrigated almonds provides a net return of $195.  However, these economic figures don’t answer questions about where the irrigation water comes from, or what happens during times of drought.  An acre of grass during drought can still be grazed; an acre of almonds must be irrigated to survive – and this irrigation water is often groundwater.

We seem to be entering an era of increased uncertainty regarding our climate and our water supply.  This uncertainty is more complicated than it would have been a generation ago; California’s growing population makes divvying up the water “pie” difficult even in normal years.  Resolving conflicts over water use will require us to accept – and embrace – the complexity of the issue.  Simply favoring one crop over another based on water use doesn’t move us down that path.

1 comment:

  1. Thanks Dan for illuminating how comparing water allocation between different ag applications is apples and oranges.