Factors affecting ammonia volatilisation from a rice-wheat rotation system

Area of Science:

• Agricultural Science
• Soil Science
• Environmental Science

Background:

• Ammonia (NH3) volatilization is a significant nitrogen (N) loss pathway in agricultural systems.
• Understanding factors influencing NH3 volatilization is crucial for optimizing fertilizer use efficiency in rice-wheat rotations.

Purpose of the Study:

• To investigate major factors affecting ammonia volatilization in a rice-wheat rotation system.
• To quantify N losses through NH3 volatilization under different urea application rates and soil conditions.

Main Methods:

• Field experiment conducted over three years (1995-1997) in Jiangsu Province.
• Continuous airflow enclosure method used to measure NH3 volatilization.
• Five treatments included varying urea application rates (0-300 kg N ha(-1)) and rice straw amendment, with a randomized block design.

Main Results:

• Nitrogen losses via NH3 volatilization ranged from 4-19% of applied N during wheat season and 5-11% during rice season.
• Soil moisture and temperature significantly influenced NH3 volatilization, particularly in the wheat growing season.
• NH3 volatilization increased with higher N application rates, but the ratio to applied N was not significantly affected.
• Rice straw amendment showed no significant effect on NH3 volatilization.

Conclusions:

• Ammonia volatilization represents a substantial N loss in rice-wheat cropping systems.
• Optimizing fertilizer management requires consideration of soil moisture and temperature dynamics.
• Further research may explore alternative N management strategies to mitigate NH3 losses.