Water Use of Wheat

A wheat crop of about 50 bushels per acre has a water requirement that is about equivalent to 10 inches. However, because water also evaporates from the soil surface, the actual amount of water needed to produce a crop is higher. Under most conditions in the Northern Plains, small grains will need between 14 and 16 inches of soil moisture per season, depending on climactic conditions and the length of the growing season.

Daily crop water use, also called evapotranspiration or ET, depends on canopy development and will generally peak between heading and early dough stage. Daily ET during this peak period can range from 0.10 to 0.30 inches depending on air temperature and cloud cover.   The table below shows estimated daily ET rates for spring wheat in central Minnesota at different stages of growth and selected maximum daily air temperature ranges. As weather is variable by location, so too will daily ET estimates vary by location. Real-time estimated daily crop ET may be observed over the Internet during the growing season at: www.ext.nodak.edu/weather/ndawn.