Abstract: To explore the effects of interplanting six legume with apple trees on carbon and nitrogen content in northwest arid orchard soil Field experiments taking Bromus inermis Leyss as the reference plant and 6 legume crops (numbered:T1-T6) as green manure plants were conducted. ¹⁵N natural abundance method and Kjeldahl method were used to detect plant nitrogen fixation and soil carbon and nitrogen content. The nitrogen fixation amount of the six green manure plants in the season was between 20.22 g·cm^-2~39.14 g·cm^-2,with T5 being the highest; After half a year,T4 had the highest total N content of legume rhizosphere soil,which was 155.48%,the alkali hydrolyzed nitrogen was 44.29 mg·Kg^-1 with the highest being T2,and the increase of microbial biomass nitrogen was 7.66%~38.74%. The total organic carbon content of soil was 22.66 g·Kg^-1 with T5 being the highest; For active organic carbon,T4 was the highest and T6 was the lowest content of 3.04 g·Kg^-1and 2.39 g·Kg^-1,respectively. The highest increase of inactive organic carbon was T5,which was 1.15 times of the control,and the highest soluble organic carbon was T4 being 0.58 g·Kg^-1. There was a positive correlation between soil microbial biomass carbon and total organic carbon and active organic carbon content. Principal component weight analysis showed the order of six plant effects on soil carbon and nitrogen content characteristics was T2>T4>T3>T5>T6>T1.

Key words: Green manure plants, ¹⁵N natural abundance method, Apple orchard, Soil carbon and nitrogen characteristics

摘要： 为探明豆科植物与果树套种对山地果园土壤碳氮含量特征的影响,本研究以无芒雀麦(Bromus inermis Leyss)为参比植物,以6种豆科作物[T1:箭筈豌豆(Vicia sativa L.)、T2:大鹁鸽灰豌豆(Pisum Large pigeon L.)、T3:绿豆(Phaseolus radiatus L.)、T4:大豆(Glycine max L.)、T5:白豌豆(Pisum sativum L.)、T6:赤豆(Vigna angularis L.)]为绿肥植物与新建果园苹果树套种,采用¹⁵N自然丰度法与凯氏定氮等方法检测植物当季固氮量及土壤碳氮含量。结果表明:6种绿肥植物当季固氮量在20.22 g·cm^-2~39.14 g·cm^-2之间,以T5最高;半年后,豆科植物根系土壤总氮含量以T4最高,为对照的155.48%,碱解氮以T2最高,为44.29 mg·Kg^-1,微生物量氮增幅为7.66%~38.74%之间;土壤总有机碳含量以T5最高,为22.66 g·Kg^-1,活性有机碳以T4最高、T6最低,分别为3.04 g·Kg^-1和2.39 g·Kg^-1,非活性有机碳以T5最高,为对照的1.15倍,可溶性有机碳以T4最高,为0.58 g·Kg^-1,土壤微生物量碳与总有机碳、活性有机碳含量间呈正相关关系。主成分权重分析显示,6种豆科植物与苹果树套种对果园土壤碳氮含量特征的影响作用效果大小排序为T2> T4> T3> T5> T6> T1。

关键词: 绿肥植物, ¹⁵N自然丰度法, 苹果园, 土壤碳氮特征