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草业学报 ›› 2023, Vol. 32 ›› Issue (3): 56-66.DOI: 10.11686/cyxb2022181

• 研究论文 • 上一篇    下一篇

氮磷添加对燕麦与箭筈豌豆不同种植方式草地土壤微生物-胞外酶化学计量特征的影响

苏乐乐1(), 秦燕1(), 王瞾敏2, 张永超1, 刘文辉1   

  1. 1.青海大学畜牧兽医科学院,青海省青藏高原优良牧草种质资源利用重点实验室,青海 西宁 810016
    2.草地农业生态系统国家重点实验室,兰州大学草地农业科技学院,兰州大学草业科学国家级实验教学示范中心,甘肃 兰州 730020
  • 收稿日期:2022-04-20 修回日期:2022-06-16 出版日期:2023-03-20 发布日期:2022-12-30
  • 通讯作者: 秦燕
  • 作者简介:E-mail: mule119@163.com
    苏乐乐(1996-),女,内蒙古鄂尔多斯人,在读硕士。E-mail: 836225845@qq.com
  • 基金资助:
    省部共建三江源生态与高原农牧业国家重点实验室自主研究项目(2022-ZZ-06);青海省科技创新平台建设专项“青藏高原种质资源研究与利用实验室”(2022-ZJ-Y01)

Soil nutrient and microbial activity responses to nitrogen and phosphorus addition in oats and arrowhead peas in monocrop and mixed sowings

Le-le SU1(), Yan QIN1(), Zhao-min WANG2, Yong-chao ZHANG1, Wen-hui LIU1   

  1. 1.Academy of Animal and Veterinary Sciences,Qinghai University,Key Laboratory of Superior Forage Germplasm in the Qinghai-Tibetan Plateau,Xining 810016,China
    2.State Key Laboratory of Grassland Agro-ecosystem,College of Pastoral Agriculture Science and Technology,National Demonstration Center for Experimental Grassland Science Education,Lanzhou University,Lanzhou 730020,China
  • Received:2022-04-20 Revised:2022-06-16 Online:2023-03-20 Published:2022-12-30
  • Contact: Yan QIN

摘要:

土壤中氮、磷养分是饲草产量与品质提高的重要基础。氮磷添加改变了土壤养分条件并引起微生物生物量及酶活性发生变化。为探究燕麦和箭筈豌豆单播、混播草地土壤微生物特性对不同氮磷处理的响应,本试验以高寒区燕麦单播草地、箭筈豌豆单播草地及燕麦/箭筈豌豆1︰1混播草地为研究对象,设置4种不同氮磷添加处理,包括单施氮肥、单施磷肥、氮磷肥配施和不施肥,研究各处理土壤微生物生物量碳氮磷和土壤胞外酶活性及其化学计量比的变化特征。结果表明:1)单施氮、磷肥均对燕麦单播草地土壤微生物生物量产生负效应;单施磷肥和氮磷配施对箭筈豌豆单播草地土壤微生物生物量产生促进作用;单施氮肥使混播草地微生物生物量碳(SMBC)增加,而氮磷配施使其微生物生物量碳氮(SMBN)降低。2)单施氮肥增加3种草地土壤β-1,4-葡萄糖苷酶(BG)活性,单施磷肥增加3种草地土壤碱性磷酸酶(AP)活性,氮磷配施增加燕麦草地土壤N-乙酰-β-D-氨基葡萄糖苷酶(NAG)、AP酶活性,表明土壤微生物通过增加C、N、P获取酶活性以增加对短缺养分的获取。3)试验3种草地土壤SMBC︰SMBN低于全国平均值,SMBN︰SMBP高于全国平均值,且土壤N︰P酶活性比大于1,表明试验地土壤微生物氮限制大于磷限制。因此,本试验中单施氮肥抑制燕麦草地土壤微生物生长,而有利于混播草地土壤微生物生长,单施磷肥和氮磷配施均有利于箭筈豌豆草地土壤微生物生长;且微生物生物量和酶活性化学计量比表明微生物通过调整体内养分含量和分泌的胞外酶含量以响应土壤养分条件的变化。

关键词: 混播草地, 氮磷添加, 微生物生物量, 土壤胞外酶, 化学计量比

Abstract:

Nitrogen and phosphorus are key nutrients for improving forage yield and quality. Nitrogen and phosphorus additions will change soil nutrient conditions and cause changes in microbial biomass and enzyme activities. This study investigated the response of soil microbial characteristics to different nitrogen and phosphorus treatments in oat and common vetch within different planting configurations. In this experiment in an alpine region, monocultures of oats (Avena sativa) or common vetch (Vicia sativa) and plots of oats mix-cropped with vetch in a 1∶1 seeding ratio were established, and four different nutrient addition treatments were applied: Nitrogen only, phosphorus only, nitrogen and phosphorus and zero added nutrients. Variation in soil microbial biomass carbon, nitrogen and phosphorus and their stoichiometric ratios, together with extracellular soil enzyme activities were the main focus of measurements. It was found that: 1) N only and P only had negative effects on soil microbial biomass in oat monocultures; P fertilizer application and combined nitrogen and phosphorus application had a positive effect on soil microbial biomass in vetch monocultures; Application of N fertilizer only resulted in increased soil microbial biomass carbon only in the mixed oat-vetch sowings, while the combined application of nitrogen and phosphorus decreased the microbial biomass carbon and microbial biomass nitrogen. 2) Added N only increased the activity of β-1,4-glucosidase (BG), while added P only increased the activity of acid phosphatase (AP). However, β-N-acetylglucosaminidase (NAG) and AP enzyme activities were increased in oat plots indicating that soil microorganisms can increase the nutrient acquisition ability by increasing the enzyme activities obtained by C, N and P. 3) For soils in this experiment, the soil microbial biomass (SMB) C∶N was lower than the national average, while the SMB N∶P was higher than the national average, and the soil N∶P enzyme activity ratio was greater than 1, indicating that the nitrogen availability restriction to soil microbial activity was greater than the phosphorus limitation at the test site. Therefore, in this experiment, the single application of nitrogen fertilizer inhibited the growth of soil microorganisms in the oat monoculture plots, but was beneficial to the growth of soil microorganisms in the mixed oat-vetch plots. Stoichiometric ratios indicate that microorganisms respond to changes in soil nutrient conditions by adjusting the nutrient content of the microbial biomass and the content of secreted extracellular enzymes.

Key words: oat-vetch mixed sowing, added nitrogen and phosphorus, microbial biomass, soil extracellular enzymes, stoichiometric ratio