Crop rotation as an effective strategy for saffron (Crocus sativus L.) cultivation

Saffron is an annual plant usually grown as a perennial crop, with well-known problems, which are related to the reduction of soil fertility (mainly caused by weeds, biotic pathologies and micronutrients scarcity) that in the long run determine a dramatic yield reduction and overexploitation of the soil. In this view, crop rotations are considered the traditional antidote to the soil sickness. However, the evidence of the effects of previous crop on saffron stigma yield and corm production is slender and fragmentary. A two-year study was carried out to evaluate the effect of three different previous crops (faba bean, saffron and fallow) on saffron stigmas yield and replacement corms production. Two different corm densities (30 and 45 corms m⁻²) were also studied. Faba bean as previous crop determined the highest performance in terms of flower number (up to 400 flowers m⁻²), stigma yield (up to 2 g m⁻²) and replacement corms (up to 4.7 kg m⁻²). This paper, to our knowledge, is the first experimental based research on the effects of previous crop on stigma and corm yield of saffron.