ORGANIC FARMING ENHANCES THE RECOVERY OF ANCIENT CROPS AND SEGETAL WEEDS IN CATALONIA (NE OF SPAIN)

The Area of Natural Interest of Gallecs (ANIG) is one of the largest areas of arable land managed organically in Catalonia. In 2005 a project was launched to convert fields to organic farming and recuperate traditional crop varieties. The aim of this work is to analyse the changes in diversity of the weed flora, including segetal and rare species, and of crops in 20 fields (ca. 50 ha) after the conversion to organic farming during 5 cropping periods (2005-2010). Number of cultivated crops has increased from 1 to 17 including ancient and local varieties of cereal and legumes. Weed biodiversity increased by a 50% in five years at field and regional scale. Crop rotations and sowing organic seeds from other farmers can contribute to the increase and the conservation of the weed diversity in the arable agroecosystems, including segetal species which are currently rare or even have disappeared from most of the conventional arable fields