Effect of Irrigation Water Depth and Plastic and Straw Mulches on Yield and Water Use Efficiency of Potato under Tape Drip Irrigation in Dehgolan Plain

Drip irrigation is one of the effective ways to conserve water and increase water use efficiency (WUE). Despite the many benefits of drip irrigation system, a substantial amount of irrigation water is wasted through evaporation from the soil and transpiration by weeds growing between the rows. Using mulch between planting rows can maintain soil moisture, reduce evaporation from the soil and transpiration from weeds, reduce irrigation water consumption, and increase crop yield. The purpose of this study was to evaluate irrigation depth and mulching effects on potato yield and water use efficiency in Dehgolan plain of Kurdistan Province. For this propose, a field experiment was conducted in the spring season of 2014, using a split plot scheme based on randomized complete blocks design with three replications. The main plots and subplots included the amount of irrigation water at four levels (60%, 80%, 100%, and 120% of the potato water requirement) and three mulch treatments (without mulch, straw mulch, and plastic mulch), respectively. Results showed that the effect of irrigation water and mulch on yield was significant (P<0.01). The maximum and minimum amounts of potato tuber yield were related to 120% and 60% water requirement, respectively. The results also showed that the effect of mulch on potato WUE was significant (P<0.01). The highest WUE (14.96 kg.m-3) was related to plastic mulch. It is to be noted that the use of plastic mulch compared to the biodegradable straw mulch will lead to environmental problems.