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Abstract
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This study evaluated the Effects of different irrigation methods and mulching on field corn (Zea mays L.) actual evapotranspiration (ETc), yield, water use efficiencies (WUE = yield/ETc, and IWUE = yield/irrigation) in Karaj of Iran. The experiment was laid out in a split plot design keeping three irrigations methods (i) porous clay capsules irrigation (CC), (ii) surface drip irrigation (SD) and (iii) subsurface drip irrigation(SDI) as the main factor and two kind of mulch (i) with and (ii) without Aluminium foil mulch as sub-factor. Each treatment was replicated three times in a randomized complete block design. Actual evapotranspiration (ETc) was calculated by water balance method. Coefficients values for kc, were derived from measured ETc and ETo calculated from weather data. Results showed that ETc of corn for Karaj was 380, 377 and 372 mm for porous clay capsules, surface and subsurface drip irrigation, respectively. However for the same period, ETc was estimated 374.22 mm using FAO Penman–Monteith model. Statistical analysis of evapotranspiration data indicated that the effects of irrigation methods were significant on evapotranspiration of corn (P≤ 0.01).The results showed that the Kc of porous clay capsules irrigation method in initial, crop development and middle stages of the growing season were 0.52, 0.78 and 1.19 respectively. The highest value of Kc was for porous clay capsules irrigation method. The effect of irrigation methods on biological yield, WUE and IWUE were significant (P<0.05). The highest yield (30 ton ha-1), WUE (7.89 kg m-3) and IWUE (7.89 kg m-3) was obtained for porous clay capsules irrigation method. The effect of mulch were significant on biological yield (P≤ 0.05), WUE (P<0.05) and IWUE (P≤ 0.05). But interaction of irrigation methods and mulch had no significant effect on biological yield, WUE and IWUE. Dry and wet biological yield increased from 25 to 28 (ton ha-1) and 63 to 97 (ton ha-1) for irrigation treatments respectively, and
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