Climate Change impact assessment and adaptation strategies for cotton-sunflower cropping system in arid environment

Abstract

The impact assessment of climate change is a basic step towards designing effective adaptation strategies. The proposed study was the model based assessment of regional climate change impacts on the cotton-sunflower cropping system. The experiments were performed in the arid environment to quantify growth, phenology, and productivity response of cotton-sunflower cropping system to sowing dates. The soil was silt loam, well drained, calcareous, alkaline, and belongs to the Miani series. The experiments on cotton were continued for two years from 2017 to 2018 and sunflower was conducted during 2017-18 and 2018-19. In the first experiment, the cotton genotypes (Cyto-179, CIM-602, and FH-142) were sown on May 10th , May 25th, June 09th, and June 24th . In the second experiment, the sunflower hybrids (Hysun-33, S-278, and NK Armoni) were sown on December 20th, January 04th , January 19th, and February 3 rd. The treatments were arranged in Randomized Complete Block Design (RCBD) in split plot arrangement having four replications. The cotton genotypes and sunflower hybrids were allocated in main plots and sowing dates were kept in sub-plot. The standard procedure was followed to record required observations. The raw data on various recorded observations were subjected to statistical analysis using Fisher’s analysis of variance technique and significance of means comparison was assessed through the least significance test at 5% probability level. The experimental data were used for calibration and validation of the Decision Support System for Agrotechnology Transfer (DSSATv4.7) to simulate growth besides productivity response of cotton besides sunflower. The model simulations were performed under optimum growth conditions, current climate, and climate change scenarios. Model accuracy was assessed by comparing the observed and simulated values by using various approaches. Climate change scenarios developed by Pakistan Metrological Department (PMD) employing climate models for the five General Circulation Models (GCMs) were based on historical baseline daily climate data, with each day’s weather variables perturbed employing changes in climate model outputs for future time periods versus those same model outputs for the one main period; “mid-century” 2040-2069 to baseline climate period (1980-2019) using RCP 8.5 was selected for integrated impact assessment.