氮、磷添加对老龄人工草地生产性能的影响

Effect of N and P addition on production performance of aging artificial pasture

为探求三江源区老龄人工草地对氮、磷添加的响应,选用尿素和过磷酸钙为试验材料,采用随机区组试验设计,研究不同施肥量对老龄人工草地群落盖度、重要值、生物量、经济效益的影响,确定老龄人工草地适合的氮、磷添加量。结果表明:单施氮肥和氮、磷合施均可显著增加草地植物盖度、物种重要值以及草地植物量,尤其是垂穗披碱草(Elymus nutans Griseb.)的盖度、重要值(P<0.05)增加明显,氮、磷合施效果优于单施氮肥(P<0.05)。单施氮肥时,垂穗披碱草生物量比CK分别提高了117.45%,165.77%,297.15%。氮、磷合施时垂穗披碱草生物量比CK分别提高了274.00%,380.03%,437.32%。以生物量为标准,生物量最高时,氮、磷合施最佳使用量为氮肥130 kg/hm^2,磷肥112.5 kg/hm^2;以最佳经济效益为标准,施肥水平是单施氮肥130 kg/hm^2。

The purpose of the study was to explore the effect of nitrogen and phosphorus addition on the aging artificial pasture in Sanjiangyuan area. Urea and superphosphate were used as fertilizers and a random complete block design was adopted to investigate the effects of different fertilization rates on the coverage,important value,biomass and economic benefit of aged grass artificial grassland. The optimal nitrogen and phosphorus addition rate of aging artificial grassland was determined. The single application of nitrogen fertilizer and combined application of nitrogen and phosphorus could significantly increase the coverage of grassland,the important value of the species and the above-ground biomass of grassland,especially the coverage and important value(P<0.05) of Elymus nutans Griseb. The combined effect of nitrogen and phosphorus was better than that of single application of nitrogen(P<0.05). Compared with CK,the biomass of Elymus nutans increased by 117.45%,165.77% and 297.15% after nitrogen fertilizer was applied alone at 75 kg/hm^2,100 kg/hm^2,130 kg/hm^2 level. After nitrogen fertilizer was applied with phosphorus,the biomass of Elymus nutans increased by 274.00%,380.03% and 437.32%. The optimal amount of nitrogen and phosphorus for the highest biomass was 130 kg/hm^2 for nitrogen fertilizer and 112.5 kg/hm^2 for phosphate fertilizer. The fertilization level for the optimal economic benefit was 130 kg/hm^2 for a single application of nitrogen fertilizer.