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Impacts of climate change on irrigation water demand, grain yield, and biomass yield of winter wheat in Nepal


Kaini, S and Harrison, MT and Gardner, T and Nepal, S and Sharma, AK, Impacts of climate change on irrigation water demand, grain yield, and biomass yield of winter wheat in Nepal, Water ISSN 2073-4441 (In Press) [Refereed Article]


The Nepalese Sunsari Morang Irrigation district is the lifeblood of millions of people in the Koshi River Basin. Despite its fundamental importance to food security, little is known about the im-pacts of climate change on future irrigation demand and grain yields in this region. Here we exam-ined the impacts of climate change on irrigation demand and grain yield of winter wheat. Climate change was simulated using Representative Concentration Pathways (RCPs 4.5 and 8.5) for three-time horizons (2016-2045, 2036-2065, and 2071-2100) in the Agricultural Production Systems Simu-lator (APSIM). For the field data measured period (2018-2020), we showed that farmers applied only 25% of irrigation water required to achieve maximum potential grain yield. Actual yields were less than 50% of potential yields. Projected irrigation water demand is likely to increase for RCP4.5 (3%), but likely to decrease under RCP8.5 (8%) due to truncated crop duration and lower maturity biomass by the end of 21st century. However, simulated yields declined by 20%, suggesting that even irrigation will not be enough to mitigate severe and detrimental effects of climate change on crop production. While our results herald positive implications for irrigation demand in the region, implications for regional food security may be dire.

Item Details

Item Type:Refereed Article
Keywords:irrigation, extreme climatic events, Representative Concentration Pathways, crop model, Sunsari Morang, APSIM, climate crisis, model, adaption, RCP, climate model, GCM, crop, yield, grain, phenology, water-use efficiency, transpiration, development
Research Division:Agricultural, Veterinary and Food Sciences
Research Group:Agriculture, land and farm management
Research Field:Agricultural systems analysis and modelling
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Adaptation to climate change
Objective Field:Climate change adaptation measures (excl. ecosystem)
UTAS Author:Harrison, MT (Associate Professor Matthew Harrison)
ID Code:152942
Year Published:In Press
Deposited By:TIA - Research Institute
Deposited On:2022-08-28
Last Modified:2022-10-24

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