阔叶类草抑制剂与氮素配施对高寒草甸土壤特性的影响  

Effects of broad-leaved grass inhibitors combined with nitrogen on soil characteristics of alpine meadow

作　　者：路欣 祁娟[1] 师尚礼[1] 车美美 李霞 独双双 赛宁刚 贾燕伟 LU Xin;QI Juan;SHI Shang-li;CHE Mei-mei;LI Xia;DU Shuang-shuang;SAI Ning-gang;JIA Yan-wei(College of Pratacultural Science,Gansu Agricultural University,Key Laboratory of Grassland Ecosystem,Ministry of Education,Gansu Grassland Engineering Laboratory,China-US Center for Grazing Land Ecosystem Sustainability,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,甘肃省草业工程实验室,中-美草地畜牧业可持续研究中心,甘肃兰州730070

出　　处：《草业学报》2023年第7期38-48,共11页Acta Prataculturae Sinica

基　　金：国家现代农业产业技术体系(CARS-34);天然草原种子基地培育关键技术研究与示范(034-031156)资助。

摘　　要：以甘南高寒草甸为研究对象,通过探究不同浓度阔叶类草抑制剂(0、0.9、1.5和2.1 kg·hm^(-2))和不同梯度氮素(0、75、150和225 kg·hm^(-2))配施对高寒草甸土壤养分及酶活性的影响,旨在筛选适宜于高寒草甸的最佳抑制剂浓度与氮肥用量的配比,为高寒区草地畜牧业的可持续发展提供科学的理论依据。结果表明:喷施较高浓度抑制剂(Y3, 2.1 kg·hm^(-2))后,土壤碱解氮、速效钾和有效磷含量均显著低于对照(P<0.05),分别较对照降低了4.89%、11.52%和14.19%,而土壤有机质含量提高了11.74%,对土壤pH影响不显著;单独氮素添加下,土壤碱解氮、有效磷含量和土壤脲酶活性均显著高于对照(P<0.05),且在施氮量为225 kg·hm^(-2)时,碱解氮、有效磷含量和脲酶活性较高,分别较对照高出4.98%、53.01%和11.28%,对土壤有机质、速效钾和土壤pH影响不显著;抑制剂与氮素添加的交互作用对除土壤pH外的各指标均存在显著或极显著影响,但较高浓度抑制剂(Y3)明显降低了氮素添加的作用效果,各施氮处理后的土壤各指标均有所降低。经灰色关联度综合分析得出,0.9 kg·hm^(-2)抑制剂与225 kg·hm^(-2)氮素配施可以明显提高土壤肥力,是一种适宜在青藏高原高寒草甸区推广的草地管理模式。This research investigated the effects of application of broad-leaved grass inhibitor and nitrogen on soil characteristics in a Gannan Alpine Meadow.The aim was to determine the optimal ratio of inhibitor concentration and nitrogen application for alpine meadow husbandry,so as to provide a scientific basis for the sustainable development of grassland and animal industries in alpine regions by exploring the effects of different concentrations of broad-leaved grass inhibitors(0,0.9,1.5 and 2.1 kg·ha^(−1)42.5% MCPA and fluroxypyr)and different nitrogen levels(0,75,150 and 225 kg·ha^(−1) Urea N≥46.0%)on the soil nutrients and enzyme activities of the alpine meadow.It was found that higher concentration of inhibitor(2.1 kg·ha^(−1))had adverse effects on soil available N,available K and available P,which were decreased(P<0.05)by 4.89%,11.52%and 14.19%,respectively,compared with the control.However,soil organic matter increased by 11.74%compared with the control and no significant difference was found for pH.Nitrogen addition alone,especially at a high rate(225 kg·ha^(−1)),had significant effects on available N,available P and urease,which were increased(P<0.05)by 4.98%,53.01% and 11.28%,respectively,compared with the control.However,nitrogen addition had no significant impact on the soil organic matter,available K and the pH levels.There were significant or extremely significant interaction effects of combined inhibitor and nitrogen addition on soil parameter except pH.Moreover,all soil indexes decreased at each level of nitrogen addition in combination with the high concentration inhibitor(Y3,2.1 kg·ha^(−1)),which indicated that high concentration inhibitor significantly counteracted the effect of nitrogen addition.According to a multivariate Grey correlation analysis,high nitrogen(225 kg·ha^(−1))combined with a low concentration inhibitor(0.9 kg·ha^(−1))provides an obvious improvement to soil fertility.In this study,we provide a grassland management framework suitable for the alpine meadow area

关 键 词：高寒草甸 阔叶类草抑制剂 氮素添加 土壤养分 酶活性 

分 类 号：S812.4[农业科学—草业科学]