内蒙古平原灌区高产春玉米(15 t hm-2以上)产量性能及增产途径

针对内蒙古平原灌区春玉米高产(15 t hm^-2以上)群体产量进一步提高难度大，产量挖潜途径不明确的问题，采用产量构成因素分析与产量性能参数分析相互验证的方法，在4年52点次高产(15 t hm^-2以上)群体产量构成因素分析的基础上，设计不同品种密度试验，研究增密对不同品种群体产量性能的影响，明确不同类型玉米品种的增产途径和栽培调控的主攻方向。结果表明，穗数和穗粒数是决定高产(15 t hm^-2以上)群体产量的主要因素。实现15 t hm^-2以上群体的产量结构为：穗数(7.08~9.60)×10⁴穗，穗粒数477~654粒，千粒重324.7~388.7 g，穗粒重168.9~234.0 g。其合理群体结构衡量指标是LAI_max在6.5以上，平均LAI在5左右，收获期LAI在3.5以上。高秆大穗型品种理想的产量结构是：67 500~75 000穗 hm^-2，每穗610~640粒，千粒重380 g左右，单穗粒重220~240 g，产量大于15 t hm^-2；株高适中的中小穗型品种，理想产量结构是： 75 000~97 500穗 hm^-2，每穗520~600粒，千粒重340~355 g，单穗粒重180~220 g，产量在16.5 t hm^-2以上。密度增加促进平均作物生长率(MCGR)和单位面积总籽粒数(TGN)的增加进而提高产量，但增密后平均净同化率(MNAR)降低导致穗粒数显著降低并限制了TGN的提高潜力。通过增密为主的结构性挖潜，使得群体功能的增益大于个体生产性能的降低，实现高产(15 t hm^-2以上)，属于“得失性补偿增产”；在优化群体结构的基础上，提高个体生产能力，突破个体库容降低的限制，进行功能性挖潜，实现群体结构和个体功能协同增益的“差异性补偿增产”，是产量进一步提高的重要途径。

Productivity Performance of High-Yield Spring Maize and Approaches to In crease Grain Yield (above 15 t ha-1) in Irrigated Plain of Inner Mongolia

It is difficult to increase grain yield (above 15 tha^-1) in irrigated plain of Inner Mongolia because of unclearness in exploring the productivity potential of high-yield spring maize colony. To solve this problem, we analyzed the yield components the yield performance parameters, and the effects of plant density on yield performance of different hybrids in split plot designs for 52 high yield maize colonies in four years,. The result showed that ear number and grain number per ear were the main factors affecting the yield of maize colony (above 15 tha^-1). The yield components of high yield colonies (above 15 t ha^-1) were as follows: 7.08×10⁴–9.60×10⁴ ears per hectare, 477–654 grains per ear, 324.7–388.7 g per 1000-grains and 168.9–234.0 g per ear. The rational indexes for high yield maize colony (above 15 t ha^-1) included the maximum LAI (leaf area index) of above 6.5, the MLAI (mean of leaf area index) of about 5.0, and the LAI at harvest stage was above 3.5. However, different hybrid cultivars demonstrated different rational yield components: cultivars with high stalk and large ear (yield over 15 tha^-1) should have 67 500–75 000 ears per hectare, 610–640 grains per ear, about 380 gram per 1000-grains, and 220–240 gram per ear; cultivars with medium or little ear on medium stalk (yield above 16.5 tha^-1) should have 75 000–97 500 ears per hectare, 520–600 grains per ear, 340–355 gram per 1000-grains, and 180–220 gram per ear. Enhancing plant density increased yield by high MCGR (mean of crop growth rate) and TGN (total grain number), but the decline in net assimilation capacity per plant resulted in remarkable reduction of GN (grain number) and thus restricted TGN potential. Adjusting population structure by increasing plant density brought about high yield above 15 tha^-1, which results from the compensation of population yield gain for individual productivity loss. Individual productivity in structure-optimized colony should be improved to break the limit of individual sink, and synchronous improvement in colony structure and individual function is the important approach to further raise yield of spring maize.