Abstract: In order to explore the effects of sowing date and planting density on the production performance and forage quality of silage corn in Haihe Plain,the biomass production,agronomic traits and forage quality of silage corn under different treatments were measured with three sowing dates and five planting densities from 2017 to 2019 by Milk2006. The results showed that sowing date and planting density had significant effects on the biomass production,milk yield per ton of dry matter and milk yield per hectare. The biomass production and milk yield per hectare of silage corn were the highest when sowing on June 5th,reaching 19.29 t·hm^-2 and 27.57 t·hm^-2,respectively The dry matter milk yield per ton of silage corn was highest under the density of 7.50×10⁴ plants·hm^-2,and the forage quality was the best. The comprehensive evaluation showed that the suitable sowing date of silage corn in Haihe Plain was about June 5th,and the planting density was (7.50~8.25)×10⁴ plants·hm^-2. In order to reduce the cost and risk of lodging,the optimal planting density was 7.50×10⁴ plants·hm^-2.

Key words: Silage corn, Sowing date, Planting density, Production performance, Forage quality

摘要： 为探讨海河平原区播期和种植密度对青贮玉米（Zea mays L.）生产性能和饲用品质的影响，2017-2019年以‘北农青贮368’、‘冀青贮1号’和‘郑单958’为试验材料，设置3个播期、5个种植密度，测定了不同处理下青贮玉米生物产量、农艺性状、饲用品质，并利用Milk2006对不同处理下青贮玉米的生物产量和饲用品质进行了综合评价。结果表明，播期和种植密度对青贮玉米生物产量、吨干物质产奶量和公顷产奶量均影响显著。6月5日播种时，3个青贮玉米品种平均生物产量和公顷产奶量均最高，分别达到19.29 t·hm^-2和27.57 t·hm^-2。不同种植密度下青贮玉米吨干物质奶产量在7.50万株·hm^-2时最高，饲用品质最优。综合评价认为：海河平原区青贮玉米适宜播种期在6月5日左右，种植密度为7.50~8.25万株·hm^-2，为降低成本，减少倒伏风险，建议适宜种植密度7.50万株·hm^-2。

关键词: 青贮玉米, 播期, 种植密度, 生产性能, 饲用品质