Perennial and annual cropping sequences differentially influence soil functionality in Luvisolic soils

Diversified cropping systems are vital for improving soil properties and resilience. This study evaluated the impact of integrating perennial forage crops into annual systems under varying nitrogen (N) levels on a Luvisolic soil, utilizing 10-year experimental plots (2013-2023) in the Peace region of northwestern Canada. The experiment in a split-plot design with four replicates had eight cropping sequences as main plots and three N rates (0, 45, and 90 kg N ha^- 1) as sub-plots. Soil samples from 0 to 15 cm depths collected in 2023 were analyzed for physical, chemical, and biological properties, and data were assessed using linear mixed models and principal component analysis (PCA). Crop diversification, including legumes and perennials improved soil aggregate stability, water-stable macro-aggregates, and enzyme activities, while N fertilization had no measurable long-term effects on these parameters. The turfgrass to legume sequence (S₇) and the annual to perennial integrated sequence (S₃) increased mean weight diameter (MWD) by 87% and 29%, respectively, relative to the conventional annual rotation. The diversified, fescue-integrated cropping sequences clearly excelled in soil structural stability parameters, increasing water-stable macroaggregates by up to 57%. PCA aligned carbon pools, structural stability, and microbial activity along with the major axis, indicating that these soil attributes collectively explained much of the observed functional variation and were more strongly influenced by crop functional group than by individual cropping sequences. Moreover, most cropping sequences exhibited overlapping soil property profiles, indicating that responses were not uniform across all systems. Integrating legumes and perennial crops into annual systems can contribute to improved soil structural stability, and biological functioning, thereby supporting sustainable cropping in the Peace region of Canada.