摘要： 旨在探讨不同施肥条件对苜蓿干草产量、植株全氮含量、植株氮素累积动态以及肥料氮素利用率等指标的影响。采用田间小区试验方法,共设5个处理:不施肥对照处理(CK)、单施化肥处理(CF)、化肥与牛粪混施处理(DM1)、化肥与沼液混施处理(DT)和减量化肥与牛粪混施处理(DM2)。结果表明,施用氮肥不仅可以增加苜蓿干物质量和氮素累积量,而且由于大幅增加苜蓿刈割前期的干物质和氮素累积速率而可能缩短其刈割周期、增加年刈割次数;多次刈割的综合结果证实在施用化学氮肥的基础上再增施有机肥仍存在增产的空间,但有机肥由于其活性氮素含量低而不能完全替代化学氮肥。在有机、无机配施情况下,化学氮肥的表观利用率为46.7%~48.1%,腐熟牛粪的氮素利用率为~9.1%, 而沼液的氮素利用率为~13.8%,因此,苜蓿生产中有机肥的氮素利用率明显低于化学氮肥。

关键词: 紫花苜蓿, 有机无机肥混施, 生物量, 氮素累积量, 肥料氮素利用率

Abstract: This study was to evaluate the impact of N application on the yield of alfalfa(one of the major feedstuffs),nitrogen(N)accumulation and N use efficiency with five treatments including CK,chemical N fertilization(CF),chemical N and cattle manure(DM1),chemical N fertilizer and digestate(DT),reduced chemical N fertilization and cattle manure(DM2).Results showed that N fertilization not only enhanced the yields and N accumulation of alfalfa,also might have a potential of reducing the period among two cuttings and increased the total cuttings during a year;Meanwhile,application of organic manure or digestate can further increased the yield but it cannot replace the chemical N fertilization.Furthermore,it was found that the N use efficiency of chemical N fertilizer was 46.7%-48.1%,9.1% for cattle manure and 13.8% for digestate,indicating the N use efficiency of organic fertilizer was lower than chemical N fertilizer.

Key words: Alfalfa, In-organic and organic N fertilization, Biomass yield, Nitrogen accumulation, N use efficiency

中图分类号: 

• S143.1