Abstract: The suitable planting density and the optimal row spacing ratio of alfalfa seed production under drip irrigation were studied, which provided theoretical guidance for the seed production under drip irrigation in semi-arid areas of northwest China. In this experiment, ‘Ganong 4’ was used as the test material to study the effects of different row spacing ratios and densities on yield and yield components under drip irrigation conditions. The results show that the number of racemes per plant, the number of reproductive branches, the number of seeds per pod and the 1000-grain weight are the main factors affecting the yield of alfalfa seeds, The number of racemes per plant has a direct effect on the contribution of individual seed yield, The contribution of the remaining three factors to yield is mainly achieved indirectly by the number of racemes per plant. In the regression fitting model of the row spacing ratio and yield, When the row spacing is 35 cm×100 cm, the actual yield per plant is the highest; when the row spacing is 15 cm×100 cm, the actual yield per unit area is the highest. The results suggest that 100 cm between-row spacing and 15 cm within-row spacing is the best ratio, When the alfalfa seeds are produced in the arid zone of central Ningxia.

Key words: Alfalfa, Within-row spacing, Between-row spacing, Yield component factor, Yield

摘要： 本试验研究滴灌条件下紫花苜蓿种子生产适宜的种植密度和最优株行距配比，旨在为我国西北半干旱地区滴灌条件下苜蓿种子生产提供理论指导。试验以‘甘农4号’苜蓿为试验材料，研究了滴灌条件下不同株行配比和密度对产量以及产量构成因子的影响，研究结果表明：每株花序数、生殖枝数、每荚种子数和千粒重是影响苜蓿种子产量的主要因素，其中每株花序数对单株种子产量的贡献起直接作用，其余3个因子对产量的贡献主要通过每株花序数间接实现。在株行配比和产量回归拟合模型中，株行距为35 cm×100 cm时单株实际产量最高；株行距为15 cm×100 cm时单位面积实际产量最高。因此，在宁夏中部干旱带进行苜蓿种子生产时，建议采用行距为100 cm，株距为15 cm的配比。

关键词: 苜蓿, 株距, 行距, 产量构成因子, 产量