草业学报2017，Vol.26Issue(4)：73-79,7.DOI:10.11686/cyxb2016164
西南地区pH影响紫色土硝化作用机制研究
Mechanisms research on how pH affects nitrification in purple soils of Southwest China
摘要
Abstract
Nitrification processes are highly sensitive to soil pH but the mechanisms through which pH affects soil nitrification are not fully understood.In the present study,three types of purple soils with different pH values were identified from the same parent material in southwest China (acid purple soil pH=5.7,neutral purple soil pH=7.3,calcareous purple soil pH=8.0).These soil types were used to investigate the long-term effects of soil pH on nitrification and ammonia oxidizers and the short-term effects of soil pH on nitrification and the activities and abundance of ammonia oxidizers.Tests were undertaken by artificially adding acid (H2SO4) or alkali (NaOH) to change soil pH.The results showed that short-term pH changes had no significant effect (P＞0.05) on nitrification in acidic and calcareous purple soils whereas they had a significant effect (P＜0.05) on nitrification in the neutral purple soil.The gene amoA of ammonia-oxidizing archaea (AOA) was expressed much more fully in the acid soil (3.04× 108/g dry soil,AOA/AOB=31.8),whereas ammoniaoxidizing bacteria (AOB) were more adapted to the calcareous purple soil environment (2.35× 108/g dry soil,AOA/AOB=0.07).These results indicate that soil pH can significantly affect nitrification in purple soils and that different pH levels have different mechanisms.The activities and community of nitrifying microorganisms were the dominant factors for nitrification in acidic and calcareous purple soils,while substrate concentration was the dominant factor in neutral purple soil.The key factor affecting the activity and community of nitrifying microorganisms is the long-term stable soil pH,while short-term pH changes mainly influence the substrate availability of nitrification.关键词
硝化作用/氨氧化古菌/氨氧化细菌/土壤pH/实时荧光定量PCRKey words
nitrification/ammonia-oxidizing archaea(AOA)/ammonia-oxidizing bacteria(AOB)/soil pH/real-time quantitative PCR引用本文复制引用
孟瑶,王智慧,罗红燕,蒋先军..西南地区pH影响紫色土硝化作用机制研究[J].草业学报,2017,26(4):73-79,7.基金项目
国家自然科学基金项目(41271267,41301315)和重庆市自然科学基金(Cstc2012JJA80024)资助. （41271267,41301315）
