Spring is on the way. The snowdrops are blooming and that means I had better be seriously getting ready for spring planting, even though they are a month early this year. “But how do you know what to plant?”
That is a lot tougher question than you might expect. It is a blending of economics, agronomics, and a bit of geography, all thrown into the maw of planting decisions, where each individual farmer balances the perceived risks and rewards according to his own ideas and experience. Though I make it sound pretty wide open, it is really not. If you study any giving farming area, it might look like crop choices are constant and tradition bound, but it is almost always tradition evolved out of biological and economic necessities. An area’s ‘traditional’ crops are those crops that have proven to be the least risky, the most economically reliable, over time. It is an evolutionary process, and farmers eagerly watch the neighbors to see which planting decisions pay off, and which don’t.
I am in traditional wheat country, but tradition is only a marginal reason for not growing watermelons. My growing season is a bit short for melons, my soil is not great for melons, and I don’t have irrigation water to keep them growing through the hot dry summer. Agronomic reasons keep a lot of crops out of traditional wheat country. In fact, for a large part of Central Washington, winter wheat is the only reliable choice.
Corn and soybeans for example, the dominant crops in the Midwest, don’t do as well in Eastern Washington’s drylands because, well, the ‘drylands’ are dry. Really dry. Single digit humidity dry. We don’t have the high summer humidity and hot nights that corn and beans love, and having lived briefly in Indiana, you will never hear me complain that we don’t have their humidity. Though continued advances in plant breeding are slowly creating new varieties of corn and other crops that are more adapted to our climate, there is still a long way to go.
Washington grows a lot of potatoes and apples, both of which were once grown on the Palouse where wheat, barley, peas, lentils, and chickpeas (or garbonzo beans) now dominate. Though we can grow apples and potatoes, we don’t because Yakima and Wenatchee can grow a lot better apples, and the Columbia Basin can grow much better potatoes. We can’t compete quality wise, or quantity wise without irrigation. Even with irrigation, I doubt if we could compete with Columbia Basin potatoes because our soil type is not as good as theirs for that crop, and our growing season is shorter.
If those agronomic hurdles were to be cleared, we would then face the economic hurdles of buying the specialized equipment to plant potatoes, pick corn, or sort apples while at the same time, trying to assure profitable markets.
Sometimes, it is processing that limits a crop choice. Most fruits and vegetables require some level of post-harvest processing, cleaning, and packaging and that requires a capital investment in equipment and manpower. An example is Canola, a crop that has been planted on limited acres here in large part because we lack access to a local crushing plant to extract the oil from the harvested seed. Also, canola prices haven’t been great, and there are pest and other agronomic problems as well.
On the other side, what we DO have is a relatively mild winter climate, not so severe most winters that fall planted wheat can’t survive it. This gives us plants already established in the ground on the first spring day when the soil temperature gets above 45 degrees and the wheat plants can start growing. Spring seeded crops miss those early growing days while we wait for the soil to be dry enough to support planting equipment.
We have amazingly deep soils with incredible water holding capacity that keeps the plants supplied with water and nutrients for weeks between rainstorms. The combination of soils that hold a lot of water, and a very dry July and August, make for ideal conditions to mature and ripen excellent quality wheat. In particular, because of June rainfall in the Eastern Palouse, we have an ideal climate for growing soft white winter wheat, the kind used for cakes, cookies, crackers and flat breads. We can grow other types of wheat, hard red winter, hard red spring, soft white spring, or hard white, but most years, our climate is best matched to soft white.
Because winter wheat is so naturally well adapted to our climate, it tends to be the crop that gives us the greatest economic return. Also, it doesn’t hurt that we have a long tradition of being reliable producers of high quality wheat that our customers overseas can access any day of the year.
So, why then isn’t every acre planted to winter wheat? “Biology,” is the short answer. When the same crop is grown repeatedly in the same soil, you select for a population of soil microbes that is adapted to living on or with that crop, including microbes that cause disease in your crop plants. You also select for the weedy plants that either mimic the life cycle of your crop, or are well adapted to growing with it. Weeds that compete with the crop for light and space and nutrients, diseases that slow the plant’s growth, or insects that feed on the plant and spread crop diseases, all reduce yield, quality and economic return.
We plant rotational crops, peas, lentils, chickpeas, spring wheat, spring barley (everything but winter wheat), so we can grow better winter wheat the next year. For me, I tend to focus on the biological reasons when deciding what to plant in rotation with winter wheat, but economic reasons dictate that I need to keep at least 1/3 of my acres in winter wheat. Others choose to, or are sometimes forced to focus more on economics. A two year rotation of wheat followed by chickpeas (garbonzo beans) or lentils has been the most profitable for several years, and some even plant winter wheat continuously. The shorter the time between winter wheat crops, however, the more susceptible those crops will be to insect, weed and disease problems, and those problems, especially disease problems can’t always be solved with a spray application.
Every field, every farm, is different, with different strengths and weaknesses that go into deciding what crop rotation to follow on that particular field. Though I plan a rotation several years in advance, sometimes I change the plan in response to a problem that flares up; a bad weed infestation one year, or a severe soil born disease may make me shift to a longer rotation. A late, wet spring may dictate that I don’t plant spring crops at all.
That is all part of the fun. No matter what you plan, or how much planning you do, you never know for sure what nature will throw in your path next year.