Abstract
A field experiment was conducted at the Agriculture Research Station of King Abdulaziz University to study the response of sudan grass (Sorghum sudanensis L.) cv. California Gold and pearl millet (Pennisetum glaucum L.) cv. KN-10. productivity to different irrigation methods and water application under arid conditions. Three irrigation methods including surface drip (SD), sub-surface drip (SSD) and sprinkler irrigation (SPI) were investigated. Under each irrigation method, one full irrigation treatment (100% of water requirement [WR]) and two water stress treatments (75% WR and 50% WR) were studied. Sudan grass and pearl millet crops were cultivated under each water regime for two consecutive seasons and cut several times for evaluating the production and irrigation water use efficiency (IWUE). Results revealed that SSD produced the highest forage yield under full and stress treatments in both crops followed by SD. SPI produced the least forage yield compared with SD and SSD in 2014 and 2015 seasons. Decreasing water application decreased yield production and increased IWUE under SD and SSD but decreased them under SPI. Increasing number of cuts decreased yield and IWUE in both crops. Under full and stress treatments, sudan grass produced higher forage yield than pearl millet. Irrigation water use efficiency was the best under SSD followed by SD and SPI, respectively. Irrigation water use efficiency of 100 and 75% were significantly similar in both investigated crops.