Crop Strategies for a Short Water Year
Plant water thrifty crops when possible. The chart at the bottom of this page shows how much water each of the crops commonly grown in Twin Falls County require. The graph above it shows monthly water use during June, July and August. Minimizing the amount of late season watering required by your crop rotation is a good strategy.
Irrigate early. Take advantage of early season irrigation to saturate the root zone to field capacity. That will give the crop a reservoir, so to speak, to draw from during the peak evapotranspiration (ET) period from July 10 to August 10. Research done by the USDA-ARS in Kimberly has shown that sugar beet growers can extend the irrigation interval by 2 to 5 days in August without reducing the sugar yields, when field capacity was reached early in the season.
Of available moisture in the soil, you can stop irrigating at early dough stage on loamy or clay soils without hurting yield.
Take advantage of alfalfa's natural water cycle of water use to stretch short water. Alfalfa crops water use starts slow, then peaks before bloom and falls back about 0.08 inches a day. By filling the soil profile early, you can withhold one irrigation from the hay and cut it when the soil surface is dry. that lets the hay cure faster and allows you to begin irrigation again when the crop water use is below ET.