Analyzing unexploitable, agronomic, and non-agronomic yield gaps in irrigated barley growing areas of arid and frost-prone regions from Iran

Abstract

Abstract The yield gap analysis is an important topic for researchers worldwide as it aims to identify the factors influencing the gap between actual and potential yields and to enhance food security. In the current study, the APSIM-Barley model was calibrated for three irrigated barley cultivars, validated using 31 field experiment reports, and applied to simulate long-term (1989 to 2019) yields under eight production levels in eight major barley growing locations of Iran (Arak, Hamedan, Kabudarahang, Marvdasht, Neyshabour, Sabzevar, Saveh and Shiraz). Three major yield gaps, namely unexploitable, agronomic and non-agronomic ones, were analyzed. The results revealed a huge difference between potential and actual yields (on average, 5.4 t ha− 1 yield gap) across the studied locations indicating that the farmers could be able to achieve only 38.6% of the potential yield. Yield gap values varied over locations and seasons. Unexploitable, agronomic, and non-agronomic yield gaps in the studied locations averaged 26.7%, 55.9%, and 17.4% of total yield gap, respectively. The major part of the agronomic yield gap in the studied locations was owing to water limitation, which accounted for ~ 40% of the agronomic yield gap, followed by other agronomic (30%), frost-limited (15.8%), cultivar-limited (13.7%), and sowing date-limited (10.4%) yield gaps. Our findings showed that by improving agronomic management practices, particularly water management and farmers’ non-agronomic conditions, the current yield gaps could be reduced considerably in arid and frost-affected locations.