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生态学杂志 ›› 2020, Vol. 39 ›› Issue (11): 3658-3667.doi: 10.13292/j.1000-4890.202011.025

• 研究报告 • 上一篇    下一篇

长期施肥对黄土旱塬农田土壤氮素生理菌群和解磷菌的影响

李春越1*,薛英龙1,王益2,党廷辉3,宋怡1   

  1. 1陕西师范大学地理科学与旅游学院, 西安 710119;2中国科学院地球环境研究所, 西安 710061;3西北农林科技大学水土保持研究所, 杨凌 712100)
  • 出版日期:2020-11-11 发布日期:2021-05-10

Effects of long-term fertilization on soil nitrogen-transforming bacteria and phosphatesolubilizing bacteria in rainfed cropland of Loess Plateau, China.

LI Chun-yue1*, XUE Ying-long1, WANG Yi2, DANG Ting-hui3, SONG Yi1#br#   

  1. (1School of Geography and Tourism, Shaanxi Normal University, Xi’an 710119, China; 2Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710061, China; 3Institute of Soil and Water Conservation, Northwest A&F University, Yangling 712100, Shaanxi, China).
  • Online:2020-11-11 Published:2021-05-10

摘要: 土壤功能微生物能促进农田生态系统养分转化和维持土壤生态环境系统稳定性。本研究基于国家黄土高原长武农业生态试验站长期定位施肥试验区,研究不施肥(CK)、施用中量氮肥(N12)、施用高量氮肥(N24)、施用中量磷肥(P12)、施用高量磷肥(P24)、施用中量氮磷肥(N12P12)6种处理下土壤可培养功能微生物氮素生理菌群和解磷菌丰度,探讨长期施肥对黄土旱塬农田土壤功能微生物活性影响及其对环境指标的响应。结果表明:长期施肥对各氮素生理菌群数量影响较大,其丰度好氧自生固氮菌>氨化细菌>亚硝化细菌>反硝化细菌;单施肥处理的氨化细菌和亚硝化细菌的变化规律相同,均随氮、磷肥施用量的增加而减少,而好氧自生固氮菌变化与之相反;无机磷细菌对氮肥的响应程度较高,磷肥对无机磷细菌丰度影响不明显;施加磷肥可降低土壤中有机磷细菌丰度,促进有机磷矿化;相关性分析表明,土壤氮素生理菌群、解磷菌丰度与各土壤理化指标存在一定程度的相关性,氨化细菌与硝态氮呈显著负相关,而与pH、田间持水量呈显著正相关;好氧自生固氮菌与全磷、速效磷、田间持水量呈极显著正相关;亚硝化细菌与全氮呈显著正相关;反硝化细菌与含水率呈显著正相关;无机磷细菌与全氮呈显著正相关,与含水率呈极显著负相关;有机磷细菌与总有机碳呈显著正相关;冗余分析显示,土壤全磷含量对土壤氮磷转化细菌作用最明显,解释了相关土壤细菌数量变化的33.2%(F=13.9, P=0.002),长期施肥对黄土区农田土壤氮素生理群和解磷菌群落丰度产生了显著影响,且氮素生理群和解磷菌在农田生态系统协同作用密切。

关键词: 长期施肥, 黄土旱塬, 氮素生理菌群, 解磷菌, 农田生态系统

Abstract: Soil functional microorganisms can promote nutrient transformation in cropland ecosystems and maintain the stability of soil environment. Based on a long-term experiment in Changwu Agro-ecological Experimental Station with six typical fertilization treatments, including no fertilizer (CK), medium nitrogen fertilizer (N12), high nitrogen fertilizer (N24), medium phosphate fertilizer (P12), high phosphate fertilizer (P24), and medium nitrogen and phosphorus fertilizer (N12P12), we explored the effects of fertilization managements on the abundance of soil nitrogen-transforming bacteria and phosphate-solubilizing bacteria by the traditional coating plate count method. The results showed that there were significant differences in the abundance of soil microorganisms involved in nitrogen cycling under different fertilization treatments. The abundance was decreased in the order of aerobic free-living nitrogen-fixing bacteria, ammonia oxidizing bacteria, nitrite bacteria, denitrifying bacteria. Ammonia oxidizing bacteria and nitrite bacteria had a similar trend in single fertilization treatments and they were reduced with the increasing nitrogen and phosphate application levels, while aerobic free-living nitrogen-fixing bacteria showed opposite responses. Inorganic phosphate solubilizing bacteria were more sensitive to nitrogen fertilizer than to phosphate fertilizer. Phosphate fertilizer decreased the abundance of organic phosphate solubilizing bacteria and promoted organic phosphorus mineralization. There were correlations between soil nitrogen-transforming bacteria, phosphate-solubilizing bacteria and soil physical and chemical parameters. The abundance of ammonia oxidizing bacteria was significantly negatively correlated with nitrate content, while positively with pH and field water-holding capacity. The abundance of aerobic free-living nitrogen-fixing bacteria was significantly positively correlated with soil total phosphorus, available phosphorus contents and field water-holding capacity. The abundance of nitrite bacteria was positively correlated with total nitrogen content. The abundance of denitrifying bacteria was significantly positively correlated with soil water content. The abundance of inorganic phosphate solubilizing bacteria was positively correlated with total nitrogen content, but negatively with soil water content. The abundance of organic phosphate solubilizing bacteria was positively correlated with total organic carbon content. Redundancy analysis results showed that soil total phosphorus content had the strongest effect on the abundance of soil nitrogen-transforming bacteria and phosphate-solubilizing bacteria, accounting for 33.2% of the variation in soil bacterial abundance (F=13.9,P=0.002). Our results indicated that the abundance of soil nitrogen-transforming bacteria and phosphate-solubilizing bacteria was significantly affected by the long-term fertilizer management in the rainfed cropland of the Loess Plateau, and that there was a closely synergistic effect between soil nitrogen-transforming bacteria and phosphate-solubilizing bacteria.

Key words: long-term fertilization, Loess Plateau, nitrogen-transforming bacteria group, phosphate-solubilizing bacteria, cropland ecosystem.