Response of potato to irrigation at varying nitrogen levels

Yield and water use of potato (cv. Cardinal) were observed under varying levels of irrigation and nitrogen in Grey Terrace Soil of Joydebpur and Calcareous Floodplain Soil of Jessore. Amount of irrigation water (20.7 cm at Joydebpur and 25.7 cm at Jessore) equivalent to 50% in excess of evapo-transpiration (ET) calculated using ten years average climatic data with the help of Penman's formula was found to be optimum for successful raising the crop. Tuber yield of potato significantly increased with higher N levels upto 160 kg/ha. Total water use by potato varied from 19.5 to 32.3 cm at Joydebpur and from 23.5 to 40.0 cm at Jessore. The water use efficiency (WUE) was higher with irrigation water just meeting ET in most cases at Joydebpur. At Jessore, irrigation water application at 50% deficit of ET showed higher WUE with any given level of nitrogen. Higher levels of nitrogen resulted in decreased total water use and increased WUE under any given irrigation level in both locations.