Keywords alfalfa;high seed yield;density;P fertilizer;racemes;pods;community ecological structure;growth tediousness;reproductive allocation;phenotypic plasticity;thin sowing;

• 紫花苜蓿;种子丰产;密度;磷肥;结荚花序数;结荚数;种群生态结构;生长冗余;繁殖分配;表型可塑性;稀植;