Opportunism is the key to taking advantage of the variability of the weather in our region of the Northern Great Plains, according to a cropping systems specialist from Montana State University in Bozeman. "We have to expect some dry years," says Perry Miller. "There's no way to know which, till well after seeding time. We know how to capture the moisture we get and protect whatever moisture is stored in the soil. Our challenge is to figure out crops and crop sequences that allow us to maximize returns from the moisture that's available. We have to stay flexible."
Low disturbance direct seeding and conservation of crop residues are the first tools for stretching soil moisture. Miller recommends early seeding and crop sequences that store and then take advantage of moisture. Fallow, the traditional moisture storage system, may be needed to keep risk manageable. But, in sequences with frequent (50%) fallow, salinity can develop as stored water moves in the soil profile. Miller advises including some medium and high water use crops - wheat, winter wheat, sunflower or mustard - in the rotation.
The other problem with fallow every two years is erosion, the old scourge of prairie farming. "Even with no-till, there's a risk of soil erosion with the broadleafs," he says. "You just can't build up a duff layer with so much fallow. And, you risk losing potential income in wet years. Perhaps a low water use crop like lentils or peas can fit in and pay a few bills when the moisture's available."