Influence of irrigation on yield, profile moisture use, water-use efficiency and net return of winter maize (Zea mays) and potato (Solanum tuberosum) intercropping

An experiment was conducted during 1987-90 with 5 irrigation treatments based on irrigation water depth : cumulative pan evaporation (IW : CPE) ratios with sole crops of maize (Zea mays L.) and potato (Solanum tuberosum L.) and their intercropping. In maize alone, maize-equivalent yield was maximum (5.38 tonnes/ha) at an IW : CPE ratio of 1.0, whereas in sole potato and in its intercropping with maize a significant increase(11.25 and 13.34 tonnes/ha respectively) was recorded up to an IW : CPE ratio of 1.2. Net return was maximum up to an IW : CPE ratio of 1.0 in sole crops of maize (Rs 6937/ha) and potato (Rs 12684/ha), whereas in intercropping stands maximum (Rs 15398/ha) net return occurred at an IW : CPE ratio of 1.2 with 7 irrigations. Water-use efficiency was maximum at an IW : CPE ratio of 0.8 in sole crops of maize and potato, and at 0.6 in the mixed crops. Soil-moisture depletion was more (42.22 mm at 1.2 ratio) from the 0-60 cm layer in the intercropped than that in pure crop of either maize (32.25 mm at 1.2 ratio) or potato (13.89 mm at 1.2 ratio).