Evaporative Loss From the Interrow of Irrigated Crops in a Semi-Arid Agricultural Area.

Soil evaporation plays an important role in the water balance of irrigated crops, especially in arid and semi-arid regions.  Irrigation scheduling may affect the fraction of evaporative loss (E) from the total evapotranspiration (ET), and thus affect the water use efficiency.  During the second intensive operation period (IOP) of the Bushland Evapotranspiration and Agricultural Remote Sensing EXperiment 2008 (BEAREX08) 10 micro-lysimeters (ML) were installed next to a large weighing lysimeter to obtain both E and ET.  In addition, sapflow measurements of transpiration (T) were conducted.  A good agreement was found between the three components (E, T, and ET).  When fraction vegetation cover was 40-50% (LAI=1), evaporative loss was 20-35% of total ET at the first 24 hours following irrigation, and reduced to 10-15% 2 to 4 days following irrigation.