Abstract

Yield of saffron (Crocus sativus L.), is the most expensive medicinal and spicy plant, which significantly respond to degree of soil fertility. In comparison to chemical Nitrogen (N) fertilizer, application of cow manure (20 to 30 t ha^-1) combined with chemical-N (23 kg/ha) to the soil surface increased significantly soil fertility. Saffron plant was treated with N as urea (CO(NH₂)₂, 46% N) at 50 to 100 kg ha^-1; and 20 to 30 t ha^-1; combination of urea (50 kg ha^-1) and cow manure (20 t ha^-1). Application of cow manure plus N fertilizers increased yield components of saffron. The highest yield (0.45 g m^-2) was obtained with the combination of cow manure and urea 50 kg ha^-1, and the lowest (0.24 g m^-2) with control. The maximum flower fresh weight (0.89 g), with the longest stigma (29 mm) were obtained in the combination of urea (50 kg ha^-1) + cow manure (20 t ha^-1) treatment, and the lowest (0.43 g) with control, respectively. The N application increased vegetative growth, but not significant on yield. Application of cow manure (20 to 30 t ha^-1) to the soil surface and mixed to 30 cm depth as soil amendments increased significantly (P = 0.05) soil organic matter (OM), soil electrical conductivity (EC), soil pH, and cation exchange capacity (CEC). There was a positive relationship between amounts of manure applied and soil in OM contents.

Key words: Saffron, nitrogen source, nutrient management, organic farm.