Crop Model Simulation Slants for Predicting and Managing the Climate Risks in Poor Rainfed Rice-Wheat Eco-System of Mid-Western Nepal: Application of APSIM, DSSAT Model and Trade off Economic Analysis
Year: 2019
Type: article
Abstract: The Agriculture is the life line of Nepalese people which contributes to more than 34% GDP and employing > 65% of total population.In Nepal, agriculture sector is in small fragmented subsistence rainfed farming system, must therefore be a special area of plan focus on other priorities such as resource use efficiency and technology to ensure sustainability of natural resources, adaptation to climate change and improvements in total factor productivity.Obviously Nepalgunj, Banke district is the hub for mid and far western development region of Nepal.Whatsoever it is the hottest place of Nepal with temperature rising well above 46°C in the summer, while minimum temperature goes down to 5°C or even below during the winter season.Annual average rainfall ranges from 1000mm to 1500mm in the district.The rice-wheat cropping system is currently practiced on about 0.5 million hectare of prime agricultural land in terai and lower basin of mid hills of Nepal.Both of the crops are grown in diverse agro-ecological environments and also seasonal diversity (rice-summer and wheat-winter) from terai to hills.All five GCMs predicted higher mean monthly maximum and minimum temperatures during the mid-century period (2040-2069) under RCP8.5 compared to the baseline .However, rainfall projections are reduction trends in all GCM predictions except GCM IIXA.Both APSIM and DSSAT simulated higher wheat and rice yields compared to survey data after the cumulative probability level except one GCM.Moreover, DSSAT simulated higher rice yields than did APSIM.Differences between the DSSAT and APSIM projections are due to differences in sensitivity of the crop models to increases in CO2 and temperature.In the case of rice, out of the 20 GCMs there is an 80% positive response both in DSSAT-rice and wheat projected a pessimistic scenario.Overall, DSSAT simulated more optimistic projections than APSIM for wheat.The integrated assessment result in DSSAT showed that mean yield of wheat crop in the future period would decline from 5% to 33% than the historic or base period.APSIM simulation also showed similar results for wheat with declining yield from 14% to 18% in the tested climate scenarios.APSIM simulation interestingly also showed 18% yield decline in rice crop in the future period in GFDL ESM2M scenario.While for the mixed crops (include crops like maize, lentil, chickpea, pigeon pea, mustard, and vegetables) an assumption was made that it would decline by 15% in all the climate scenarios in the future period.Overall, the simulation results showed that the mean net farm returns would decline by 14% to 16% in DSSAT and 14% to 24% in APSIM in the tested climate scenarios.The simulation results in different climate scenarios have shown mixed results in per capita income (PCI), net farm returns and poverty rate.Both the crop model simulations (DSSAT and APSIM) have shown higher PCI, net farm returns and reduction in poverty in the future period in those scenarios where increase in rice yield is higher than decrease in wheat yield in future than the base period and vice versa.The results showed a very small difference (less than 1%) in the poverty rate in between future and current period.DSSAT simulation has shown higher percentage of gainers (farm populations gaining in future period) in HadGEM2-ES, MIROC5, and MPI-ESM-MR scenarios while APSIM simulation has shown higher percentage of gainers CCSM4 and MIROC5 scenarios.Both the crop model simulations have shown higher percentage of losers in GFDL ESM2M scenario.Various RAP parameters and other estimates
Source: Acta Scientific Agriculture
Language: English
Subfield: Agronomy and Crop Science
Domain: Life Sciences
SDGs: Zero hunger, Climate action
Open Access status: diamond
OpenAlex ID: W2981646178