Department of Agronomy, National Taiwan University, Taipei, Taiwan.
Taichung District Agricultural Research and Extension Station, Council of Agriculture, Changhua, Taiwan.
PLoS One. 2023 Apr 17;18(4):e0284290. doi: 10.1371/journal.pone.0284290. eCollection 2023.
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 season, 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.
为提高灌溉农业用水效率，需要对作物需水量进行调查。本研究的主要目的是评估整个主要种植季节水分亏缺胁迫对水稻产量的影响。我们分析了 1925 年至 2019 年台湾田间试验的水稻产量数据，以评估水分亏缺胁迫对 12 个水稻品种产量的影响。利用空气温度、湿度、风速、日照时间和降雨量等气象数据，计算了水稻生长阶段参考蒸散量和作物水分状况（CWS）的时间趋势。负的 CWS 值表示作物缺水，较小的值表示作物生长中的水位较低（水分亏缺胁迫较大）。在 95 年间，凉爽种植季节水稻生长的初始、作物发育期、生殖期和成熟期的 CWS 分别下降了 96.9、58.9、24.7 和 198.6 毫米，温暖种植季节则分别下降了 63.7、18.1、8.6 和 3.8 毫米。CWS 的递减趋势代表水分亏缺胁迫的增加。在初始、作物发育期、生殖期和成熟期，1925-1944 年、1945-1983 年和 1996-2019 年各品种与水分亏缺胁迫相关的总产量变化分别为-56.1 至 37.0、-77.5 至-12.3、11.2 至 19.8 和-146.4 至 39.1 千克/公顷在凉爽的种植季节和-16.5 至 8.2、-12.9 至 8.1、-2.3 至 9.0 和-9.3 至 8.0 在温暖的种植季节。我们的研究结果表明，CWS 可能是水稻在发育阶段茁壮成长的决定因素，但不是生殖阶段。此外，近年来水分亏缺胁迫对水稻生长的影响越来越大。
