The Subtlety of Summer Drought on California Rangelands

With Labor Day and our local Gold Country Fair behind us, I find my thoughts turning to autumn.  This morning, I went through all of our mature ewes, checking them for udder problems and teeth problems, and de-worming any that seemed to have internal parasites.  We call this process "bagging and mouthing" - we check udders for hard lumps that indicate a past bout of mastitis (these lumps inhibit a ewe's ability to produce milk - and to feed her lambs).  We check the ewes' mouths to see if all of their teeth are intact - a ewe that is missing teeth is not able to graze as efficiently, which can also impact milk production.  Finally, we check the color of every ewe's third eyelid.  An eyelid that is vibrant and pink indicates that that ewe is relatively free from barberpole worms, one of the most common summer parasites in sheep.  An eyelid that is pale indicates anemia - a symptom of parasitic infection.  Those with pale eyelids are given an oral de-wormer.  We only treat the infected ewes because we don't want to make the parasites resistant to our de-wormer by overusing it (plus, it saves us money!).  After sorting off 13 ewes for hard bags, bad teeth, or poor performance during last spring's lambing season, I took the rest of the flock - next year's brood ewes - to a neighboring property with irrigated pasture to start the "flushing" process.  Flushing means that we are putting the sheep on a rising plane of nutrition (they've been on dry grass), which should increase their ovulation rates (and, hopefully, the number of twins born next spring).  We've been managing our limited irrigated pasture this year with flushing in mind - we sold most of our lambs at weaning (rather than finishing them on irrigated pasture) with the idea that the ewes would graze our irrigated pasture now.  This long-winded explanation of what we're doing now serves as a backdrop for the continuing impacts of California's drought on our operation.  This dry year, which was so up-in-our-face last winter, is much more subtle in California's normally dry summer months, at least for a rangeland-based livestock operation like ours.

Unlike many farms in California, we've been blessed with adequate irrigation water this summer.  The Nevada Irrigation District (NID), which supplies our water, purchased extra water from Pacific Gas and Electric this spring.  This purchase, along with water conservation measures, means that NID will go into this winter with adequate carry-over supplies in its reservoir system.  For us, the purchase has meant that we've received our normal water deliveries on the irrigated pastures that we graze.  But irrigated pasture is only a small part of our operation.  We have the ability to irrigate about 20 acres of pasture near Auburn, which represents about 5 percent of our total acreage.  We graze on about 400 acres of annual rangeland - land that is not irrigated.  In other words, we rely on rainfall to grow forage for our sheep for most of their needs.  Indeed, our entire management calendar revolves around the rainy season and the flush of spring grass growth - we time our lambing to coincide with spring grass.

Most of California has a Mediterranean climate, characterized by a distinct rainy season (late fall, winter and early spring) and a distinct dry season (late spring, summer and early fall).  Last winter's record-setting dry period meant that our rangelands didn't have much green grass in January and February - and even into March.  The drought, as I've written, had a profound impact on our operation.  Since we've been able to irrigate this summer, the drought's impacts have been much more indirect (unlike the impacts on farmers in the Central Valley).  For example, many of the oak trees on the rangelands we graze seem stressed by the lack of soil moisture - they have started dropping leaves well before the autumn equinox.  We're also seeing unusual forage conditions because of the timing and amount of rainfall last year - we have much more wild oats on many of our rangelands.  While some dry grass has nutritional value for our sheep, dry wild oats are not very nutritious or palatable.  And finally, because of the dust that has been prevalent on our rangelands and in our corrals since last winter, we are seeing some increased problems with pneumonia.  Dust can cause respiratory infections in livestock, and we've been treating more cases of this than normal.

Some of these subtle impacts are psychological, too.  California's annual rangelands are always brown and dry in early September, and yet I find that I'm getting more anxious about the onset of the rainy season than I normally do at this time of year.  I find myself looking at the weather forecast with greater scrutiny - will the El Niño predicted for California actually materialize, and will it result in higher than average precipitation?  We have planned our grazing carefully for the coming months - we'll have enough dry forage to last us into March of next year - but find myself worrying about what will happen if this winter turns out like last winter.

To paraphrase Will Rogers, a farmer (or rancher) has to be an optimist or he wouldn't keep farming.  In three-and-a-half weeks, we'll turn our rams in with the ewes - the ultimate act of optimism in a sheep rancher's year.  We're betting the rains (and the green grass) will come.  We hope we're right!