Corm plays a pivotal role in the life cycle of saffron plant. In order to find and recommend a method for improving the growth of daughter corms using soil organic amendments in semi-arid areas, a split plot experiment in randomized complete block design including three irrigation intervals of 30, 50 and 70 days as main plots and three factors of vermicompost, Terracottem, and Bolourab-A as sub plots was conducted for two years -2014-2016-. The results showed that the highest number of daughter corms was observed in Bolourab-A and irrigation interval of 50 days in the second year, and the highest average weight -14.8 g- was related to Terracottem and 30-day irrigation round in the first year. The highest percentage of standard and non-standard daughter corms in the first year was obtained in combined vermicompost + Bolourab- A and 50-day irrigation interval, control and 30-day irrigation interval treatments, respectively. The highest amount of nitrogen uptake was in Terracottem + Bolourab- A and 50-day irrigation interval treatments also phosphorus and potassium were in vermicompost + Terracottem and irrigation in 50 and 70 days in the first year, respectively. The highest dry matter content was obtained in treatment of vermicompost + Bolourab- A and 30-day irrigation, also the highest yield daughter corms -36.4 ton.ha-1- and water use efficiency -5.2 kg.m-3- were observed in irrigation interval of 70 days and Bolourab- A + Terracottem,vermicompost + Terracottem treatments, respectively. In general, soil organic amendments can be used in combination to increase the efficiency of available water resources and improve some characteristics of daughter corms of saffron in semi-arid regions.

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