Simulated CSM-CROPGRO-cotton yield under projected future climate by SimCLIM for southern Punjab, Pakistan

Climate change is widely affecting the agriculture sector in Pakistan with an estimated annual loss of up to 16 billion dollars by the end of 21st century (GOP, 2015). Southern Punjab is famous for producing more cotton than the entire province of Sindh in Pakistan but here the climatic variations largely affect the cotton production. The present research was carried out in Vehari, an arid area of Southern Punjab, Pakistan, to determine the intensity of the climatic impacts on the projected agricultural production of cotton in southern Punjab for 2025 and 2050 using SimCLIM(climate model) with CSM (crop simulation model)-CROPGRO-Cotton by comparing with observed data (2013 and 2014).The integrated assessment model (IAM) SimCLIM uses a statistical approach for regional downscaling. Scenarios for two general circulation models (GCMs) (BCC-CSM1–1 and MIROC5) and three greenhouse gas concentration pathways (RCP-8.5, 6.0, 4.5) were developed. The three levels of phosphorous (0, 57, and 114kg ha−1) were applied to find the yield output of cotton cultivars (MNH-886 and FH-142) for the prediction of development and yield with different GCMs. The model predicted that FH-142 would give a higher percentage yield than MNH-886 for 2025 and 2050; the lowest percentage yield would be for MNH-886 at maturity for three RCPs. The lowest percentage change in the yield was projected for MNH-886 by RCP-8.5 (−0.77) and (−0.85) for 2025 and 2050, respectively. Farmers might have to apply a moderate level of phosphorous (57kg P ha−1)to avoid the potential threat of climate change. Both the cultivars MNH-886 and FH-142 are suitable for 57kg P ha−1, but cultivar FH-142 performed better when compared to MNH-886 for GCM and three RCPs.