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Updated: May 9, 2026
10:29
Calibrated Passive Sampling - Multi-plot Field Measurements of NH3 Emissions with a Combination of Dynamic Tube Method and Passive Samplers
Published on: March 21, 2016
Preceding crops may reduce denitrification potential and enhance ammonium assimilation pathways
Juan Li1, Ming Liu1, Chengwei Yang1
1Dali Prefecture Branch of Yunnan Tobacco Company, Dali, Yunnan, China.
Frontiers in Microbiology
|May 8, 2026
Summary
Barley and rapeseed preceding crops boost soil microbial richness and activity in tobacco fields. This enhances nitrogen fixation while reducing denitrification by altering ammonium dynamics.
Area of Science:
- Agricultural Science
- Soil Microbiology
- Biogeochemistry
Background:
- Soil microorganisms are crucial for nitrogen cycling in agricultural systems.
- The impact of preceding crops on soil microbial functional profiles is not well understood.
- Understanding these interactions is key to optimizing nutrient management in croplands.
Purpose of the Study:
- To investigate the effects of barley (BT) and rapeseed (RT) as preceding crops on soil microbial functions and nitrogen (N) metabolism in tobacco fields.
- To compare these effects against a control without preceding crops (CK).
- To identify key soil factors influencing microbial community structure and function.
Main Methods:
- Field study comparing barley, rapeseed, and no preceding crop treatments.
- High-throughput metagenomics to analyze soil microbial community composition and function.
- Measurement of soil denitrification rates and enzyme activities (e.g., glutamine dehydrogenase).
- Statistical analysis including redundancy analysis to correlate soil properties with microbial data.
Main Results:
- Barley and rapeseed significantly increased soil microbial richness (Chao1 index) compared to the control.
- Preceding crops altered the relative abundance of key metabolic pathways.
- Denitrification rates were reduced, while glutamine dehydrogenase activity increased under preceding crop treatments.
- Ammonium-N concentration was identified as a critical factor influencing microbial community structure and function.
Conclusions:
- Barley and rapeseed preceding crops enhance soil microbial richness and activity.
- These crops modulate nitrogen cycling by inhibiting denitrification and promoting nitrogen fixation.
- Altered ammonium-N dynamics play a significant role in these observed microbial and functional changes.
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