Water use efficiency of potato (Solanum tuberosum L.) under different irrigation methods and potassium fertilizer rates

This study was conducted to determine the effect of different irrigation methods and potassium fertilizers on potato yield in the Abu–Graib–Baghdad, Iraq Region, during season 2011–2012. Potato was grown under furrow and drip irrigation methods and three potassium fertilizers rates applied with 0.0, 300 and 600 kg K2SO4 ha−1. The obtained results indicated that, actual potato evapotranspiration ranged from 357.3 to 511.4 mm in the growth season for all treatments. Furrow and drip irrigation methods had no significant effect on tuber yield under the experiential conditions. Potassium fertilizer influenced the tuber yield (P < 0.05), and the highest tuber yield was registered for 600 kg K2SO4 ha−1, reaching 35.23 T ha−1and 36.65 T ha−1for furrow and drip irrigation, respectively. Water use efficiency increased from 5.129 to 7.379 kg m−3 for furrow-irrigated treatments, and from 6.907 to 10.257 kg m−3 for drip-irrigated treatments using the above mentioned rate of K-fertilizer.