WATER TEMPERATURE-FLUCTUATIONS AND EFFECT ON IRRIGATION INFILTRATION

An infrared thermometer measured the temperature of irrigation water flowing in furrows in fields of com and onions. The temperature increased as much as 22-degrees-C from inflow to downstream ends of the field during mid-afternoon. This temperature increase reduces the viscosity of the water sufficiently to increase the hydraulic conductivity by 70%. Computer simulations determined the effect of measured temperature increases on cumulative infiltration and on distribution of infiltrated water during a hypothetical irrigation. For the case studied, the elevated downstream temperature improved the uniformity of infiltrated water down the furrow.