Evaluation and Comparison of Drip and Conventional Irrigation Methods on Sugar Beets in a Semiarid Region

Abstract

A field study was conducted on sugar beet during a two-year period to investigate the effects and comparison of different irrigation methods and treatments on crop yield, irrigation water use efficiency (IWUE), and pan coefficient determination in a semiarid region with limited water resources. The experiments were in complete randomized blocks design. Three replications were used with different levels of irrigation water amounts (25, 50, 75, and 100%), evapotranspiration (ET) of sugar beet seasonal water requirement with surface drip tape (SDT), and conventional furrow irrigation method (CFI), with and without soil and water monitoring, and comparison with CROPWAT modeling. The variety of sugar beet was Rasool. The highest and lowest average irrigation water use efficiencies on the basis of root yield with 16.16 and 9 kg/m3, and sugar yield with 3.82 and 1.33 kg/m3, for both experimental years was achieved under different irrigation treatments of T4 (25% ET) SDT and CFI, respectively. The results of this study showed that by using drip tape irrigation method with different treatments (100% ET), (75% ET), (50% ET), (25% ET), instead of conventional furrow irrigation method with and without soil, water, and root monitoring, (28.8, 46.6, 64.5, and 82.2%) and (38.4, 53.8, 69.2, and 84.6%) of sugar beet seasonal irrigation water requirement can be saved, respectively. The results also showed that sugar beet average annual water, requirement under conventional furrow irrigation method with soil, water, and root monitoring was almost 8.4% and 28.70% lower compared to CROPWAT modeling and conventional furrow irrigation without monitoring. Additionally, this study showed a pan coefficient (Kp) equal to 0.80 for the investigated semiarid region.