Over the last several weeks, I've been interviewed by a number of local, state and national media outlets about the impacts of the drought on our operation and on California ranchers in general. Usually the discussion focuses on options for feeding our way out of drought - purchasing hay and other feedstuffs to make up for the lack of grass on our rangelands. Even the most farm-savvy reporters seem somewhat surprised that our strategy leans more towards selling animals than toward buying feed. As I talk to customers and others who are not in the ranching business - and even to some who are in the business on a smaller scale - I find that they are also surprised. Why, they ask, can't you feed your way out of this drought?
My answers have tended towards the economic reasons - with higher demand for hay, I simply can't afford to feed all of our sheep. Basic business principles tell us that if our costs of production are higher than our sales revenue, we can't be sustainable in an economic sense. But the real reason that de-stocking (that is, selling our breeding animals) is our primary strategy has more to do with the ecological sustainability of our operation. If we're going to stay in ranching over the long haul, the land must come first.
First, I should probably discuss some basic principles of grazing management and describe how they fit into our operation. In a "normal" year, we try to abide by the principle of "take half, leave half" on both our unirrigated rangelands and on our irrigated pastures. Grass growth on unirrigated rangeland is measured in pounds per acre, and we try to leave at least 800 pounds of standing grass at the end of the growing season (which usually happens in May). We leave this much "residual dry matter" for several reasons:
- It provides a micro-environment that encourages earlier germination once the fall rains commence by moderating temperature, retaining moisture and protecting new grass seedlings.
- It protects our soils by providing root structure and intercepting the energy of falling rain drops - in other words, it prevents erosion.
- It helps give more desirable plants a leg up on invasive weeds (generally). Invasive weeds tend to like disturbed or bare soils.
- Finally, saving this much dry grass gives us a stockpile of dry forage going into the fall months. Dry grasses are not terribly nutritious for our livestock (we generally need to provide some supplemental nutrition), but we time our production system to be able to graze our ewes on this dry feed when they have lower nutritional demands.
Based on past experience, we may be lucky to grow 800-1000 pounds of grass on some of our rangelands this year, so taking half would leave us under this threshold going into next fall. If we graze too much this spring, we create the potential for erosion and weed infestation next year - and we'd have little or no fall feed for our ewes.
On irrigated pasture, we use the "take half, leave half" principle for a slightly different reason. Grass grows by capturing sunlight energy with it's "solar panels" or leaves. As we graze (that is, as our sheep remove the solar panels), we reduce the ability of the grass to capture sunlight energy. Following a grazing, the grass will draw energy from its roots to begin regrowing its leaves. Once the leaves are big enough, they once again can capture enough sunlight to meet the needs of the entire plant. We try to time our grazing to allow for this full recovery before we graze again - if we don't, we'll eventually kill the root system (and the rest of the plant). If we turn sheep into a pasture with 12-inch-high grass, we try to graze it down to 6 inches. With this much leaf material left, the grass recovers more quickly - in May and June, we might be able to graze it again in 25 days. As the weather grows hotter, recovery takes longer - we might need to wait 35-40 days. Over the years, we've found that a more severe graze (taking the grass down to 2-4 inches, for example) lengthens the recovery period significantly. In a year like this, where summer irrigation water will likely be in short supply, it will be even more important to leave enough grass. We may have to dry up some of our irrigated pastures in late summer, and research done by the University of California indicates that our pastures are more likely to survive if we leave 4-5 inches of residual after our last grazing.
Based on these principles, we look at two factors in determining our management approach. First, we consider the carrying capacity of our land - that is, we look at the supply that Mother Nature gives us. This year, it's looking like Mom will be pretty stingy, but we don't have any control over this component. We can, however, control our demand - we can adjust our stocking rate (or the number of mouths we need to feed) to bring demand into balance with supply. This gives us a couple of options:
- We can reduce our stocking rate by selling animals. We've started this process and will continue to re-evaluate our flock size as the year progresses.
- We can supplement or replace our grasses by feeding our sheep. As I've indicated, this option doesn't make sense economically for us. Furthermore, if we're feeding in our pastures, we'll continue to impact what little grass there is.
- We can take animals to new pastures that have not been grazed. Fortunately, it's much easier to do this with sheep than with cattle - we can utilize smaller properties and don't require much in the way of infrastructure (we bring our own fencing and water systems in most cases). We are also pursuing this option at the moment.
As with any changes to a business, one should always consult his or her banker. Our banker, obviously, is concerned with our ability to meet our financial obligations. Those of us who ranch, however, must work with much more demanding banker - the land. An overdraft notice from Mother Nature means we're out of business.