Effect of climate change-induced water-deficit stress on long-term rice yield

RESEARCH ARTICLE Effect of climate change-induced water-deficit stress on long-term rice yield Hungyen ChenID1*, Yi-Chien Wu2, Chia-Chi Cheng2, Chih-Yung Teng2 1 Department of Agronomy, National Taiwan University, Taipei, Taiwan, 2 Taichung District Agricultural Research and Extension Station, Council of Agriculture, Changhua, Taiwan * chenhungyen@ntu.edu.tw Abstract The water requirements of crops should be investigated to improve the efficiency of water use in irrigated agriculture. The main objective of the study was to assess the effects of water deficit stress on rice yields throughout the major cropping seasons. We analyzed rice yield data from field experiments in Taiwan over the period 1925–2019 to evaluate the effects of water-deficit stress on the yield of 12 rice cultivars. Weather data, including air temperatures, humidity, wind speed, sunshine duration, and rainfall were used to compute the temporal trends of reference evapotranspiration and crop water status (CWS) during rice growth stages. A negative CWS value indicates that the crop is water deficient, and a smaller value represents a lower water level (greater water-deficit stress) in crop growth. The CWS on rice growth under the initial, crop development, reproductive, and maturity stages declined by 96.9, 58.9, 24.7, and 198.6 mm in the cool cropping season and declined by 63.7, 18.1, 8.6, and 3.8 mm in the warm cropping season during the 95 years. The decreasing trends in the CWSs were used to represent the increases in water-deficit stress.

The total yield change related to water-deficit stress on the cultivars from 1925–1944, 1945– 1983, and 1996–2019 under the initial, crop development, reproductive, and maturity stages are -56.1 to 37.0, -77.5 to -12.3, 11.2 to 19.8, and -146.4 to 39.1 kg ha-1 in the cool cropping season and -16.5 to 8.2, -12.9 to 8.1, -2.3 to 9.0, and -9.3 to 8.0 in the warm cropping sea- son, respectively. Our results suggest that CWS may be a determining factor for rice to thrive during the developmental stage, but not the reproductive stage. In addition, the effect of water-deficit stress has increasingly affected the growth of rice in recent years. Introduction Global climate change, including increased temperatures and fluctuating rainfall, has become a threat with a high potential to affect the water supply and agricultural sectors [1–3]. The increase in temperature and decrease in rainfall negatively affects the growth of plants because plants are subjected to temperature and water stress due to an increase in evapo- transpiration [4, 5]. The impact of climate change on the hydrological cycle, water balance, and runoff characteristics has emerged as a significant stressor at local and district levels, although there are uncertainties regarding the impacts of climate variability on water PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0284290 April 17, 2023 1 / 14 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Chen H, Wu Y-C, Cheng C-C, Teng C-Y (2023) Effect of climate change-induced water-

deficit stress on long-term rice yield. PLoS ONE 18(4): e0284290. https://doi.org/10.1371/journal. pone.0284290 Editor: Josily Samuel, CRIDA: Central Research Institute for Dryland Agriculture, INDIA Received: September 22, 2022 Accepted: March 28, 2023 Published: April 17, 2023 Copyright: © 2023 Chen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting information files. Funding: This work was supported by funding from the National Science and Technology Council, Taiwan (109-2313-B-002-027-MY3) and Taichung District Agricultural Research and Extension Station, Council of Agriculture, Executive Yuan, Taiwan (111a20-1) to HC. There was no additional external funding received for this study. Competing interests: The authors have declared that no competing interests exist.