Yield gap analysis of chickpea under semi-arid conditions: A simulation study

Yield gap analysis provides an essential framework to prioritize research and policy efforts to reduce yield constraints. To identify options for increasing chickpea yield, the SSM-chickpea model was parameterized and evaluated. The model was applied to analyze seed yield at both potential and water limited production levels and subsequently to find the yield gap for nine different locations. Study locations are selected to represent major chickpea-growing areas of Khorasan Razavi province (located between 37 degrees N and 33 degrees S latitude and 61 degrees E and 56 degrees W longitude). The average simulated potential yield of chickpea across all study locations was 2251 kg ha(-1), while for the water limited yield was 1026 kg ha(-1), indicating 54% lower due to adverse soil moisture conditions. Average irrigated and rainfed actual yields were 64% and 79% less than simulated potential and water limited yields respectively. Maximum and minimum of simulated potential yield minus simulated water limited yield (YG(MM)) and simulated potential yield minus irrigated actual yield (YG(MI)) were observed in Torbat-Jam and Quchan, respectively. Generally, YG(MI) and YG(MM) showed an increasing trend from the north (including Neishabur, Mashhad, Quchan and Daregaz) to the south of the study province (Torbat-Jam and Gonabad). In comparison to other indices, simulated water limited yield minus rainfed actual yield (YG(MR)) was very low because both simulated water limited and average rainfed actual yields were low in these locations. Overall, YG(MR) was almost unaffected by the quantity of rainfall received at these locations.