Improving barley yields in organic stockless farming systems through innovations in green manure management

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Low and fluctuating yield levels of barley on stockless farms converted to organic farming shows that organic feed barley production in Norway is a challenge. This is mainly because of insufficient nitrogen (N) supply, but also problems with soil structur e in intensive arable cropping systems. The main source of plant nutrients in organic stockless cereal production is from soil organic matter and leguminous green manure crops within the crop rotation. Due to high N concentrations in green manure crops, a nd current practice with repeatedly mowing and leaving these as green mulch on the stubble, substantial amounts of N from green manure is at risk of being lost from the cropping system. Such losses represent a reduction in fertilizer value of the green ma nure, and increases potential N pollution to the atmosphere and watercourses. The main objective of the project is to improve yields of feed barley on stockless organic farms. This is to be achieved through investigations on how selected green manure m anagement and biogas slurry application from digested green manure herbage can improve N cycling and N utilization, and how these management strategies will affect soil structure and key grain quality parameters. The results will be implemented in tools f or practical fertilization planning, and contribute towards increased domestic feed barley production to supplying the growing market for organic meet and dairy products.