One way to avoid these long run or short run costs is to match irrigation to crop needs. This ET information can serve a key role in irrigation management decisions. Water from precipitation or irrigation can enter the soil where it comes into contact with the crop root system. Evapotranspiration is the water removed from our soils by soil evaporation and plant transpiration. The change in water tension from the soil, through the plant and into the atmosphere.
Soil evaporation is a direct pathway for water to move from soil to the atmosphere as water vapor.
Soil evaporation rates are highest after irrigation or rainfall. At those times the soil surface is wet and the water readily evaporates. As the soil dries the soil evaporation rates decline. Plant transpiration is evaporation of water from leaf and plant surfaces. Transpiration is the last step in a continuous water pathway from soil, into plant roots, through plant stems and leaves, and out into the atmosphere.