CAJ | 학술논문

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75 kg／hm2（N1），150 kg／hm2（N2），225 kg／hm2（N3）和0 kg／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。
이1999년건식적5개불동화초조합혼작초지위대상，연구련속량년불동시담량75 kg／hm2（N1），150 kg／hm2（N2），225 kg／hm2（N3）화0 kg／hm2（CK）대초지생산력적제승급군락특정적종합영향。결과표명，련속2년시담균가불동정도제승고한지구인공화초초지적생산력화초층고도，단일정정도강저료초지군락적물충다양성화봉부도。N2제도가재유효제고초지생산력적동시，경호유지건식화초적우세지위화물충적다양성수평，시해지구15령인공초지개량적최가시담량。불동적화초혼작조합양지급불동시담년빈대시담적향응존재일정차이，수수피감초비중교대적양지대담비적향응교기타화초경위민감。연구야증명，과량시담혹단순련속시담대고한지구다년생화초혼작초지군락적은정성회조성일정영향。
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.