Zhang Xin, Zhang Ying, Zhang Haowen, Wang Kun, Tan Yuechen, Xiao Guangmin, Meng Fanqiao
State Key Laboratory of North China Crop Improvement and Regulation, College of Resources and Environmental Sciences, Hebei Agricultural University, Baoding, 071000, China; Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, Beijing Key Laboratory of Biodiversity and Organic Farming, College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100193, China.
State Key Laboratory of North China Crop Improvement and Regulation, College of Resources and Environmental Sciences, Hebei Agricultural University, Baoding, 071000, China; College of Information Science and Technology, Hebei Agricultural University, Baoding, 071000, China.
J Environ Manage. 2022 Jun 1;311:114818. doi: 10.1016/j.jenvman.2022.114818. Epub 2022 Mar 2.
Ammonia volatilization (AV) dominates the pathway of nitrogen (N) fertilizer losses in crops throughout the world. However, different methods are highly responsible for the different measurements of AV. The existing techniques were separated into static chamber methods (SCM), dynamic chamber methods (DCM), calibrated Dräger-tube method (DTM) and micrometeorological methods (MMM), which were analyzed by a meta-study of 595 observations from 33 published studies. An exponential relationship (P < 0.01) was found between AV and the N fertilizer applied to wheat and maize using all the methods. The amount of AV using SCM was the lowest. The AV monitored by DCM was 24.5%-55.0% (wheat) and 46.9%-65.0% (maize) lower than that for the DTM. Additionally, the AV measured by DTM did not differ significantly in the wheat season but was 58.9% lower (P < 0.05) in the maize season than that in the MMM. To reveal the influencing factors responsible that were for DCM and DTM, a field experiment was conducted during the period of Oct. 2016 to Oct. 2017. The study indicated that the AV was 15.8%-28.3% (wheat, P < 0.05) and 36.7%-44.2% (maize, P < 0.05) lower when monitored by the DCM than when estimated by DTM. The concentration of soil NH-N, air temperature, and wind speed positively correlated with the NH fluxes. In addition, there was a significant linear correlation (P < 0.01) between the AV measured by DCM and DTM when the wind speed was <1.5 m s. This study highlighted the fact that wind speed was the main factor that caused the large difference between DCM and DTM. Herein, DTM or MMM was first recommended, and DCM was accepted when wind speed was <1.5 m s for quantitative estimates of AV. However, only a straight comparison between DCM and DTM under the same field experiment was done, the other comparisons only being based on similar fertilization and environmental conditions. Consequently, the differences between methods have to be treated carefully.
