College of Earth Sciences, Jilin University, Changchun 130012, China.
Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Changchun 130102, China.
Int J Environ Res Public Health. 2019 Apr 4;16(7):1211. doi: 10.3390/ijerph16071211.
Maize yield has undergone obvious spatial and temporal changes in recent decades in Northeast China. Understanding how maize potential yield has changed over the past few decades and how large the gaps between potential and actual maize yields are is essential for increasing maize yield to meet increased food demand in Northeast China. In this study, the spatial and temporal dynamics of maize potential yield in Northeast China from 1990 to 2015 were simulated using the Global Agro-ecological Zones (GAEZ) model at the pixel level firstly. Then, the yield gaps between actual and potential yields were analyzed at city scale. The results were the following. (1) The maize potential yield decreased by about 500 kg/ha and the potential production remained at around 260 million tonnes during 1990-2000. From 2000 to 2015, the maize potential yield and production increased by approximately 1000 kg/ha and 80 million tonnes, respectively. (2) The maize potential yield decreased in most regions of Northeast China in the first decade, such as the center area (CA), south area (SA), southwest area (SWA), and small regions in northeast area (NEA), due to lower temperature and insufficient rainfall. The maize potential yield increased elsewhere. (3) The maize potential yield increased by more than 1000 kg/ha in the center area (CA) in the latter 15 years, which may be because of the climate warming and sufficient precipitation. The maize potential yield decreased elsewhere and Harbin in the center area (CA). (4) In 40 cities of Northeast China, the rates of actual yield to potential yield in 17 cities were higher than 80%. The actual yields only attained 50-80% of the potential yields in 20 cities. The gaps between actual and potential yields in Hegang and Dandong were very large, which need to be shrunk urgently. The results highlight the importance of coping with climate change actively, arranging crop structure reasonably, improving farmland use efficiency and ensuring food security in Northeast China.
近几十年来，中国东北地区的玉米产量经历了明显的时空变化。了解过去几十年玉米潜在产量的变化情况，以及潜在产量与实际产量之间的差距有多大，对于增加玉米产量以满足东北地区日益增长的粮食需求至关重要。本研究首先利用全球农业生态区模型（GAEZ）在像素水平上模拟了 1990 年至 2015 年中国东北地区玉米潜在产量的时空动态，然后在城市尺度上分析了实际产量与潜在产量之间的产量差距。结果表明：（1）1990-2000 年，玉米潜在产量减少了约 500kg/ha，潜在产量保持在 2.6 亿吨左右；2000-2015 年，玉米潜在产量和产量分别增加了约 1000kg/ha 和 8000 万吨。（2）在第一个十年，中国东北地区大部分地区（如中心区、南区、西南区和东北小地区）的玉米潜在产量下降，这主要是由于温度较低和降雨量不足。其他地区的玉米潜在产量则有所增加。（3）在后 15 年，中心区（CA）的玉米潜在产量增加了 1000kg/ha 以上，这可能是由于气候变暖以及降水充足。其他地区以及中心区的哈尔滨玉米潜在产量则有所下降。（4）在东北 40 个城市中，有 17 个城市的实际产量达到潜在产量的 80%以上；有 20 个城市的实际产量仅达到潜在产量的 50%-80%；鹤岗和丹东的实际产量与潜在产量之间的差距非常大，亟待缩小。研究结果强调了积极应对气候变化、合理安排作物结构、提高耕地利用效率和确保东北地区粮食安全的重要性。
