Integrating Diverse Cover Crops for Fallow Replacement in a Subtropical Dryland: Implications on Subsequent Cash Crop Yield, Grain Quality, and Gross Margins

Integrating cover cropping into crop–fallow rotation has been considered a key component of ecological intensification that could mitigate negative productivity and sustainability challenges associated with conventional fallow practices. However, the adoption crops in water-limited environments limited by potential soil water nitrogen (N) costs resulting yield penalties. We examined impacts diverse on mineral N dynamics legacy subsequent cash crop profitability. The used (forage oat—Avena sativa L. [grass], common vetch—Vicia subsp. L.)/fababean—Vicia faba [legume], forage rape—Brassica napus [brassica]) differed functional traits related to growth, phenology, acquisition use strategies. found grass-associated generally supported higher grain profit than brassica- or legume-associated crops, mainly due moderate biomass accumulation persistent groundcover. Cash yields increased +19% +23% following oat crop, concomitant gains gross margins +96$ ha?1 +318$ for maize winter wheat compared fallow. In contrast, brassica-associated ranged from +8 ?21% reduced ?229 ?686$ relative Legume- had lowest mungbean added stubble. were production, accumulation, residue carbon ratio, through effects availability at sowing. Given additional margin benefits they may provide alternative management option improve system resilience environments.