Biomass Production and Nitrogen Use Efficiency in Dill-Fenugreek Intercropping in Response to Biofertilizers and Manure

Medicinal plants’ intercropping system is a relatively new approach to enhance their sustainable production. The aim of this study was to evaluate the response of fenugreek-dill to the integrated application of manure and bio-fertilizers in the intercropping system.

In a field experiment during the growing season of 2020, the effect of manure levels (no application, 6 and 12 t ha-1), either inoculated or non-inoculated with N-fixing bacteria on biomass production, land equivalent ratio (LER), Area-time equivalent ratio, land use efficiency, agronomy efficiency of fertilizer (AEF), and nitrogen use efficiency (NUE) in monoculture compared to different intercropping patterns of dill:fenugreek (75:25, 50:50, and 25:75) were examined.

The results showed that the decrease in biomass production due to the decrease of fenugreek cropping ratio was compensated by 100% fertilization and bacterial inoculation which led to an increase in NUE, AEF, LERf, and the whole system advantageous in 75:25 and 50:50 dill:fenugreek intercropping ratios. Despite the decrease in biomass production and NUE with decreasing dill ratio in intercropping, biomass production under bacterial inoculation and 50% fertilization did not show any significant difference with 100% manure application, which led to increased AEF, NUE, and LER in these conditions.

According to the results, 25:75 and 50:50 dill:fenugreek intercropping ratios under 100% fertilization and bacterial inoculation can increase the total advantageous indices and NUE. For sustainable production of dill, 75:25 dill:fenugreek intercropping ratio inoculated with bacteria in 50% manure application can be recommended.