Database of field experiments on the effect of organic farming on yield and yield stability in European arable land

The database consists of 50 field experiments located in 45 sites with mostly loamy soil texture across 15 European countries, covering European climate zones, from Boreal to Mediterranean South. Mean annual precipitation and mean annual temperature measured at the experimental sites included in this meta-analysis ranged from 360 mm to 1,050 mm and from 3.4 °C to 16.3 °C, respectively.A total of 7 studies each from Sweden and Poland were included, 6 from Italy and Spain, 4 from Denmark and Estonia, 3 from Germany, 2 from Finland, Latvia, Norway, Switzerland and the UK, and 1 from Austria, the Netherlands and France. In organic systems, animal-based fertilizers (manure, slurry, manure compost) was applied in 11 studies, plant-based fertilizers (legumes and mixed green manure) in 24 studies, and both types of organic fertilizers in 13 studies. N input in organic systems was less than in conventional systems in 24 studies, equal in 3 studies, higher in 4 studies, and not reported in 19 studies. In most studies, fields were conventionally tilled and not irrigated. The duration of cereal-based organic systems ranges from 3 to 35 years. Yields of winter wheat, winter rye, spring barley, spring wheat, or oats were measured from 3 to 30 years, and the duration of organic rotations varied from two to eight years.