摘要
以1999年建植的5个不同禾草组合混作草地为对象,研究连续两年不同施氮量75kg/hm2(N1),150kg/hm2(N2),225kg/hm2(N3)和0kg/hm2(CK)对草地生产力的提升及群落特征的综合影响。结果表明,连续2年施氮均可不同程度提升高寒地区人工禾草草地的生产力和草层高度,但一定程度降低了草地群落的物种多样性和丰富度。N2梯度可在有效提高草地生产力的同时,更好维持建植禾草的优势地位和物种的多样性水平,是该地区15龄人工草地改良的最佳施氮量。不同的禾草混作组合样地及不同施氮年份对施氮的响应存在一定差异,垂穗披碱草比重较大的样地对氮肥的响应较其他禾草更为敏感。研究也证明,过量施氮或单纯连续施氮对高寒地区多年生禾草混作草地群落的稳定性会造成一定影响。
Five different gramineous mixed pastures planted in 1999 were studied,and pasture productivity and plant community characteristics were recorded during two consecutive years of N fertilization at 75 kg N/ha (N1 ),150 kg N/ha (N2 ),225 kg N/ha (N3 ),or 0 kg N/ha (CK).N fertilization enhanced the pasture produc-tivity and height of these alpine pastures,but reduced plant species richness and diversity to some extent.The optimal fertilization rate for these 15 year old pastures was 150 kg N/ha per year,as this application rate im-proved pasture productivity and maintained the dominance of gramineous species in the plant communities.The nitrogen response differed between years and pasture with a large proportion of Elymus nutans was more re-sponsive to N fertilizer than other pasture types.This experiment also demonstrated that single N fertilizer ap-plications may enhance community stability or productivity of these alpine,perennial,mixed cropping cultivat-ed grasslands.
出处
《草业学报》
CSCD
北大核心
2015年第9期130-137,共8页
Acta Prataculturae Sinica
基金
现代农业产业技术体系(CARS-35)
国家自然科学基金(31360569)
甘肃"退牧还草"
"打草场建设"项目资助
关键词
人工草地
多年生禾草
混作
施氮
改良
cultivated grassland
perennial grass
mixed cropping
nitrogen fertilization
improvement
