Long‐term evaluation of organic management of durum wheat in Central Italy

Abstract Italy is the most important European producer of organic (ORG) durum wheat [ Triticum turgidum spp. durum (Desf.) Husn.]. Growth and yield of durum wheat are affected by weather conditions and by management systems (MS). The objective of this research was to determine the long‐term impact of two different MS (ORG and conventional [CON]) and their interactions with weather conditions on durum wheat yields. The study was part of a long‐term experiment in Pisa, Italy, comparing crop performance in a 5‐year rainfed rotation (i.e., sugar beet [ Beta vulgaris L. var. saccharifera ] or maize [ Zea mays L.] followed by common wheat [ T. aestivum L. subsp. aestivum emend. Thell.], sunflower [ Helianthus annuus L.], faba bean [ Vicia faba L. var. minor ], and durum wheat) over 15 years under ORG and CON MS. Durum wheat yields were 37% lower under ORG compared to CON on average, though similar yields were produced across the two systems during one of the 5‐year cycles. There was a significant interaction between MS and climatic conditions for yield and yield components. A lower number of spikes per m 2 was observed in ORG wheat compared to CON, thus spotlighting on likely different soil N availability in the two MS at the double ridge stage. ORG management resulted in weed biomass increases over time, with 400% higher weed biomass under ORG by the end of the research period. The high interannual variability across both MS confirms that multi‐year studies are needed to demonstrate the relative productivity of ORG versus CON MS.