Toward dormant seeding of rainfed chickpea as an adaptation strategy to sustain productivity in response to changing climate

Abstract

Dormant seeding management (DSM) is a useful adaptation strategy to sustain chickpea grain yield particularly under climate change. Accordingly, the SSM-Legumes model was employed to evaluate the effects of DSM versus fixed sowing dates (at three levels) and cultivars (early-, mid- and late-maturity) on chickpea production and water use efficiency in eight locations in west and northwest of Iran. Daily climatic data from 1980 to 2010 was collected from the Meteorological Organization of Iran as baseline. Projections of the future climate was accomplished in Miroc5 (Model for Interdisciplinary Research on Climate) GCM for the future of 2040–2070 under RCP4.5 and RCP8.5 emission scenarios using the methodology presented by AgMIP (Agricultural Model Intercomparison and Improvement Project). The results showed that DSM2 (dormant seeding around late February) × a mid-maturity cultivar produced much higher grain yield (1382 kg ha−1) in comparison to other combinations of sowing dates and cultivars in baseline. However, in the future, ILC482 × DSM1 (dormant seeding around 20 December) showed the best performance in terms of grain yield (1350 and 1484 kg ha−1 for RCP4.5 and RCP8.5, respectively. Results also indicated that water use efficiency was much higher in DSM1 and DSM2 (3.6 and 4.6 kg ha−1 mm−1, respectively) compared to the fixed sowing dates in baseline. However, combination of DSM2 × ILC482 in baseline, resulted in 1.3 kg ha−1 mm−1 greater water use efficiency than DSM1 × ILC482. In the future, ILC482 cultivar under DSM1 showed highest water use efficiency (5.2 and 5.8 kg ha−1 mm−1 for RCP4.5 and RCP8.5, respectively). Overall, DSM in combination of a mid-maturity cultivar under climate change could be considered as a suitable adaptation strategy to increase the length of growing season, coincide winter and early-spring rainfalls with the critical period of chickpea growth and consequently increase grain yield and water use efficiency.