氮添加对高寒生态条件下垂穗披碱草草地土壤肥力的影响  

Effects of Nitrogen Addition on Soil Fertility of Elymus nutans Grassland under Alpine Ecological Conditions

作　　者：牧仁 焦婷[1] 陈鑫 马淑敏 张霞 祁娟[1] 鱼小军[1] Muren;JIAO Ting;CHEN Xin;MA Shu-min;ZHANG Xia;QI Juan;YU Xiao-jun(Pratacultural College,Gansu Agricultural University/Grassland Ecosystem Key Laboratory of Ministry of Education/Sino-US Research Centers for Sustainable Grassland and Livestock Management,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学草业学院/草业生态系统教育部重点实验室/中-美草地畜牧业可持续发展研究中心,甘肃兰州730070

出　　处：《中国草地学报》2022年第5期50-57,共8页Chinese Journal of Grassland

基　　金：甘肃农业大学科技创新基金(青年导师扶持基金)(GAU-QDFC-2018-04);现代农业产业技术体系(CARS-40-09B)。

摘　　要：为探究不同氮素添加水平对高寒生态条件下垂穗披碱草草地土壤肥力的影响,试验选取祁连山高寒草地开展垂穗披碱草草地氮素添加研究。采用单因子试验设计,设5个氮素添加水平,分别为0kg/hm^(2)(N0)、12kg/hm^(2)(N1)、24kg/hm^(2)(N2)、48kg/hm^(2)(N3)和96kg/hm^(2)(N4),每处理4次重复。于2020年7月和8月施肥两次后,9月采集各处理0~10cm、10~20cm、20~30cm土层样品测定肥力指标,研究不同施氮水平对土壤肥力的影响。结果表明:随施氮量增加,10~20cm土层有机质含量呈增加趋势,在N4处理下较对照增加39.17%(P<0.05),0~10cm土壤碱解氮和速效磷含量呈先升后降趋势,分别在N2和N3处理下达到最大值,土壤速效钾在N4处理下达到最大值。同一施氮水平下,除N4处理外,随着土层深度的增加,土壤速效养分含量总体呈下降趋势,土壤有机质在N3和N4施氮水平呈先升后降趋势。总体来看,施氮对土壤全量养分、pH值及含水量影响不明显。双因素方差分析表明,施氮水平对土壤全氮产生显著影响(P<0.05),土层深度对有机质、速效磷及速效钾产生显著或极显著影响(P<0.05或P<0.01)。灰色关联度分析表明,仅从改善高寒生态条件下垂穗披碱草草地土壤肥力效果来看,48kg/hm^(2)施氮量效果较好。In order to explore the effect of different nitrogen addition levels on soil fertility of Elymus nutans grassland under alpine ecological conditions,Elymus nutans grassland in Qilian Mountain area was selected for research.The single factor experiment design was adopted,and five nitrogen addition levels(treatments)were set,which were 0kg/hm^(2)(N0),12kg/hm^(2)(N2),48kg/hm^(2)(N3)and 96kg/hm^(2)(N4),respectively.Each treatment was repeated for 4 times.After fertilizing twice in July and August 2020,soil samples of 0~10cm,10~20cm,and 20~30cm soil layers were collected in September to determine the fertility indexes.The results showed that the content of organic matter in 10~20cm soil layer increased with the increase of nitrogen application.N4 treatment increased by 39.17%compared with the control(P<0.05).The content of alkali hydrolyzable nitrogen and available phosphorus in 0~10cm layer first increased and then decreased,the maximum value was reached under N2 and N3 treatment respectively.Soil available potassium reached the maximum under N4 treatment.For the same nitrogen level,except for N4 treatment,with the increase of soil depth,the content of soil available nutrients showed a downward trend,the content of soil organic matter first increased and then decreased in N3 and N4 treatment.In general,the effect of nitrogen application on total soil nutrients,pH value and water content was not obvious.Two-way ANOVA showed that nitrogen application levels had a significant effect on soil total nitrogen(P<0.05),and soil depth had a significant or extremely effect on organic matter,available phosphorus and available potassium(P<0.05 or P<0.01).Grey correlation analysis showed that 48kg/hm^(2) nitrogen application showed better fertility efficiency only from the perspective of improving soil fertility of Elymus nutans grassland in alpine ecological conditions.

关 键 词：高寒草地 生态条件 氮素 垂穗披碱草 土壤肥力 

分 类 号：S543.9[农业科学—作物学] S812.2