Weed Suppression, Biomass and Nitrogen Accumulation in Mixed-Species and Single-Species Cover Crops in a Tropical Sugarcane Fallow

While mixed-species cover crops are gaining worldwide popularity, their utility in the ‘plough-out’ period tropical sugar cane systems has not been investigated. Field trials investigating weed suppression (one season only), biomass production and nitrogen accumulation of single-species were conducted over two seasons on a commercial sugarcane farm Australian tropics. Mixed-species showed strong suppression, among top treatments for each year, but did yield highest either season. Sunn hemp (Crotalaria juncea cv. Global sunn) produced most drier-than-average 2016–2017 (>10 t dry matter ha−1), while soybean (Glycine max Leichardt) (5.3 ha−1) wetter-than-average 2018–2019 season, highlighting influence seasonal conditions species’ production. The inclusion multiple species short-term crop tropics where extreme weather events can occur thus be seen as risk mitigation strategy given failure any