effect of pumice on water retention capacity in soil, growth and yield of spring safflower in dryland conditions

application of superabsorbent material is one of the new methods for moisture storage in the soil. this research was performed in the khajeh research station on the basis of randomized complete block design with three replications in the plots with dimension of 4×5 meter for investigate the effect of different amounts of pumice on water retention capacity in the soil, growth and of spring safflower in rainfed condition. experimental treatments were five levels of pumice (a: zero, b: 5, c: 10, d: 15 and e: 50 ton ha-1). before cultivation, amounts of pumice calculated for each plot and then mixed with soil to depth of 20 cm. then, cultivation was performed in the seeding and the number of germinated seeds at first ten days of cultivation was determined. soil volumetric water content and plant height was measured at various times during growth season, 1000 grain weight and grain yield of safflower was measured in the end of growth season. the results showed that application of pumice in the soil led to significant increase in volumetric water content, germination, 1000 grain weight, grain yield (p < 0.01) and plant height (p < 0.05). so adding pumice soil improves soil physical conditions (total porosity, water retention capacity of the soil and prevent the formation of crust on the soil surface) that it leads to increase in growth and yield of plants.