The relationship between crop yield and plant density in maize is essential for improving cropping system because of the fact that maize compensates for low plant density is less than other cereals such as wheat. To determine the evolution trend of yield-density relationships from maize plant density experiments reported in China, and to provide potential approaches to im-prove maize yield, based on requirements for meta-analysis, we collected the historical data of maize plant density experiments from the 1950s to 2000s in China containing values more than 1500 pairs of plant densities and their crop yield. Evolution trends of maximum crop yield, optimal plant density and yield per plant within six decades were examined after all eligible data sets were subject to fitting parabola model and further to statistical analyses such as histogram, correlation, and path. Crop yields in the 1970s and 1980s were considerably higher than those in the 1950s and 1960s. Crop yield steadily increased in recent three decades and reached the maximum of 10.5 t ha-1. Annual yield increment was 150 kg ha-1 after 1960s. Optimum plant densities for different decades varied from 4.5 to 6.8 plant m-2, showing (1950s and 1960s)<(1970s and 1980s)<1990s>2000s. Yield per plant for different decades varied from 0.08 to 0.17 kg and in the order:1950s>(1960s and 1970s)<1980s, then gradually in-creased after 1980s, with a greet increase in 2000s. Crop yield loss due to departures from the optimal plant density appeared an increased trend in recent three decades. On the basis of increasing plant density, promoting yield per plant throughout breeding and cultivation approaches may lead to a higher level of maize production.% 为明确中国玉米产量-密度试验结果的年代演化趋势,进一步探索提高玉米产量的突破方向和理论依据,汇集从1950s到2000s中国玉米产量-密度的文献结果,拟合产量-密度抛物线模型,剔除异常后进行直方图、相关、通径等Meta分析.结果表明,1950s和1960s玉米产量明显低于1970s和1980s,1990s以来产量持续增加,2000s最大,为10.5 t hm-2,1960s以来年均增益150 kg hm-2.最佳密度年代均值在4.5~6.8株 m-2之间,呈现(1950s 和1960s)<(1970s和1980s)<1990s,但是,2000s却小于1990s.最佳密度下单株产量年代均值在0.08~0.17 kg之间,呈现1950s>(1960s和1970s)<1980s,且1990s以来持续上升,2000s上升幅度更为明显.1990s以来密度偏离最佳值引起的减产幅度呈现上升趋势.在持续增加密度的同时,通过育种和栽培途径提高单株产量,是玉米更高产的努力方向.
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