|Hong, Eun-mi - Orise Fellow|
|Nam, Won-ho - University Of Nebraska|
|Choi, Jin-yong - Seoul National University|
Submitted to: Agricultural Water Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2015
Publication Date: 1/1/2016
Citation: Hong, E., Nam, W., Choi, J., Pachepsky, Y.A. 2016. Projected irrigation requirements for upland crops using soil moisture model under climate change in South Korea. Agricultural Water Management. 165:163-180.
Interpretive Summary: Irrigation needs are changing in response to climate change. Modification of irrigation practices is expected to be site-and crop-specific. Crop modeling allows for the development of country-wide or region-wide overviews to project changes in irrigation needs and patterns. The objective of this work was to evaluate the overall trend, and crop-specific trends, in the effect of irrigation water availability on the sustainability of agricultural production for 29 crops in upland South Korea. We found that the overall trend is that increasing water scarcity will be a major limiting factor for agricultural sustainability; cereal crops will be less vulnerable than produce. Some of vegetable crops will experience a strong longitudinal trend of vulnerability. Overall, the strong interplay of crop, soil, and meteorological parameters was observed in simulations. Results of this work are expected to be of use in regional and national planning to adopt mitigation measures to improve irrigation and soil water management for upland crops in South Korea.
Technical Abstract: An increase in abnormal climate change patterns and unsustainable irrigation in uplands cause drought and affect agricultural water security, crop productivity, and price fluctuations. In this study, we developed a soil moisture model to project irrigation requirements (IR) for upland crops under climate change using estimated effective rainfall (ER), crop evapotranspiration (ETc) and the IR of 29 major upland crops in South Korea. The temperature and precipitation will increase, but the ER is projected to decrease under climate change. ETc and the net irrigation requirement (NIR) are expected to increase under climate change. Vegetable crops have less ER and more NIR than cereal crops with a similar amount of ETc, which means they are more sensitive to water scarcity and IR than cereal crops. In addition, we found that barley has the smallest daily ETc and IR but the highest increase rate in NIR under climate change, especially in the central part of South Korea. The NIR of Chinese cabbage-fall is the lowest in the northern region and increases moving southwards. The NIR of spinach is projected to increase gradually from the southern and eastern coastlines to the northern inland area. Onions have the largest ETc and NIR of the 29 upland crops, but they show small changes compared to other crops under climate change. Water scarcity is a major limiting factor for sustainable agricultural production. The variation of IR and ETc values for each crop under different climate change scenarios depends on the crop, soil, space, and meteorological characteristics. The results of this study can be used as a guideline for irrigation and soil water management for upland crops under climate change.