Effect of vermicompost application on seed yield and quality in fababean (Vicia faba L.) and fennel (Foeniculum vulgare L.) intercropping

To compare the replacement intercropping patterns of fennel (Foeniculum vulgare Mill.) and faba bean (Vicia faba L.) at different levels of vermicompost, a field experiment was conducted as factorial arrangement in randomized complete block design with three replications at the research field of the Faculty of Agriculture, Urmia University, Iran, in growing season of 2018. Experimental treatments included six planting ratios: sole cropping of fennel and faba bean, one row of fennel + one row of faba bean, two rows fennel + two rows faba bean, three rows faba bean + two rows fennel, four rows faba bean + two rows fennel, and two levels of vermicompost: 0 and 10 t.ha-1. The results showed that the highest seed yield (2568.33 kg.ha-1) of fennel was obtained in the sole cropping and the lowest seed yield (1396.67 kg.ha-1) was belonged to the one row of fennel + one row of faba bean, respectively. Essential oil and oil content (%) of fennel were higher in all intercropping system than in sole cropping. Application of vermicompost could increase seed yield, essential oil content, essential oil yield, oil conten (%) and fennel oil yield by 20.48%, 14.52%, 32.72%, 11.12% and 29.37,  in comparison with control (no application of vermicompost), respectively. The highest amount of E-anethole of essential oil (79.9%) and oleic fatty acid (83.1%) of fennel were obtained from three rows of faba bean + two rows of fennel with vermicompost consumption. The highest land equivalent ratio (1.42) was obtained in the  three rows faba bean + two rows fennel intercropping system fertilized with vermicompost, indicating that intercropping improved land use efficiency by 42%, when compared to sole cropping. This cropping system was identified more suitable for increasing land use efficiency particularly in the medicinal plants production systems.