effect of 10-year continuous saffron cultivation on physical and chemical properties of soil

the effect of 10-year continuous saffron cultivation on physical and chemical properties of a silty clay loam soil was investigated in a research farm of college of agriculture, shiraz university, shiraz (52 º 33ʹ e longitude and 29º 36ʹ n latitude), iran. this farm was irrigated with different regimes (100% of saffron's potential evapotranspiration (etp), 75%etp, 50%etp) including rain fed treatment under two irrigation methods (basin and furrow irrigation). the results showed that the values of electrical conductivity, sodium adsorption ratio, arsenic, boron and soil bulk density of soil in the root zone increased significantly, but the final infiltration rate decreased significantly compared to the original soil. the value of ph in 100%etp and 75%etp treatments decreased and in 50%etp and rain fed treatments increased compared to the original soil. corms under high irrigation treatment had more weight up to a 6-year cultivation. however, after that, the corm weight declined to levels equal to or less than the low irrigation treatment cases. the number of total corms increased up to 6 years of cultivation and decreased after that. so, the continuous saffron cultivation causes some undesirable change in soil chemical and physical properties, which become pronounced after 6 years of cultivation.