Assessing the potential of cover crop mixtures in a faba bean cropping system under boreal climatic conditions

Abstract

Poor soil conditions and boreal climatic conditions in Newfoundland and Labrador (NL) are the major constraints in the establishment of cover crop (CC) mixtures. CC mixtures were grown as an additional forage source, which not only provided biomass but also balanced soil C:N ratio, scavenged N and improved soil health. An experiment (June 2022- September 2023) was conducted in Pasadena, NL, where fourteen CCs mixtures were introduced in a faba bean cropping system. The combinations composed of two-way and three-way CC species of legumes [red clover (RC), berseem clover (BC), hairy vetch (HV) and birdsfoot trefoil (BT)] and cereals [fall rye (CR), annual ryegrass (AR) and triticale (TR)] in a randomized complete block design. The results showed that CC mixtures were successfully established and highest DMY was observed for HVCR and RCCR. While BCAR and RCAR exhibited better fodder quality as compared to other CC mixtures. CC mixtures also improved the forage quality of the faba bean, weed suppression and benefit-cost-ratio. However, CC mixtures have a non-significant impact on faba bean yield stability. CC mixtures had a significant impact on SMBC while no significant effects on POX-C, POM-N, POM-C, MBN, and soil mineral N. PLFA analysis showed that CC mixtures have significant impact on G⁻, G⁺, total bacterial population and total PLFA content while had no significant effects on fungi and protozoa population. This research concluded that CC mixtures showed good DMY and forage quality along with improvement in weed suppression, benefit-cost-ratio, SMBC, and bacterial population.