Review Soybean yield physiology and development of high-yielding practices in Northeast China Xiaobing Liu a, * , Jian Jin a , Guanghua Wang a , S.J. Herbert b a Laboratory of Black Soil Ecology, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, Harbin 150081, PR China b Department of Plant, Soil and Insect Sciences, University of Massachusetts, Amherst, MA 01003, USA Received 9 June 2007; received in revised form 13 September 2007; accepted 27 September 2007 Abstract Soybean (Glycine max (L.) Merrill), one of the most important crops in China, has been known to man for over 5000 years. Soybean production in China increased from 7.5 million Mg in 1978 to 26 million Mg in 2005. The largest production areas in China are in the Northeast China’s three provinces, where soybean is spring seeded and grown as a full-season crop. Development of research programs and rapid adoption of technologies emerging from agricultural research by producers including a better understanding of the physiological processes of growth and development, improved cultivars and cultural practices, and a higher demand of the soybean processing industry has contributed much to the upward trend in on- farm yield and total production. Research on leaf area index (LAI), light interception and canopy photosynthesis, source–sink relationships, phytohormones, environmental stresses (drought and cold damage), development of cultivar selection, tillage systems, cultivation practices as well as weeds, insects and diseases during the last half century in Northeast China were reviewed. The intent is to document a summary of the understanding of soybean physiology and culture for high yields mainly from Chinese scientists’ perspective. # 2007 Elsevier B.V. All rights reserved. Keywords: Soybean; Northeast China; Production; Yield physiology; Culture practices; Past half century Contents 1. Yield, production, acreage changes and problems in soybean culture in Northeast China ............................ 158 2. LAI, light interception and canopy photosynthesis ....................................................... 159 3. Source–sink relationships, and phytohormones ......................................................... 161 4. Environmental stresses .......................................................................... 162 5. Cultivar selection and development ................................................................. 164 6. Tillage system and cultivation practices .............................................................. 165 7. Weeds, insects, and diseases ...................................................................... 167 8. Conclusions.................................................................................. 167 Acknowledgements ............................................................................ 168 References .................................................................................. 168 Soybean (Glycine max (L.) Merrill), a native of China and one of the most important crops in the country, has been known to man for over 5000 years. As a main soybean producer of the world, soybean production in China increased from 7.5 million Mg in 1978 to 15 million Mg in 1999 (Lu and Wang, 1999), and to 26 million Mg in 2005 (Liu and Bi, 2006). Average yield in China increased from 1.06 Mg ha À1 in 1978 to 1.83 Mg ha À1 in 1999, but declined to 1.76 Mg ha À1 in 2005. The largest production areas in China are in the Northeast China’s three provinces: Heilongjiang, Jilin, and Liaoning. Heilongjiang is the main soybean producer in the region. Soybean is spring seeded in these areas and grown as a full-season crop. Sown acreage and total www.elsevier.com/locate/fcr Available online at www.sciencedirect.com Field Crops Research 105 (2008) 157–171 * Corresponding author. Tel.: +86 133 59721155; fax: +86 451 86603736. E-mail address: xbxliu@yahoo.com (X. Liu). 0378-4290/$ – see front matter # 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.fcr.2007.09.003