1. Ammonia volatilisation following urea fertilisation in an irrigated sorghum crop in Italy.
- Author
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Ferrara, R. M., Loubet, B., Decuq, C., Palumbo, A. D., Di Tommasi, P., Magliulo, V., Masson, S., Personne, E., Cellier, P., and Rana, G.
- Subjects
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AMMONIA , *IRRIGATION , *SORGHUM , *UREA as fertilizer , *PLANT canopies - Abstract
Ammonia (NH3) fluxes were estimated by three inverse modelling methods over a sorghum field following the application of 240kgNha-1 of urea pills under a semi-arid Mediterranean climate. Ammonia volatilisation started following irrigation, which coincided with the third urea application. The maximum volatilisation rate was reached 7 days after irrigation. A clear dependence of the NH3 volatilisation on irrigation and rainfall events was observed. The NH3 fluxes ranged from -2.5 to 45 μg NH3 m-2 s-1. The canopy compensation point jumped from 9μg NH3 m-3 before urea hydrolysis to 131 μg NH3 m-3 afterwards, while the soil compensation point varied in the meantime from 24 to 800 μg NH3 m-3 on average. The soil-dominated observed NH3 emissions were reasonably well reproduced by a two-layer resistance model. Overall, between 10% and 14% of the total nitrogen applied was volatilised. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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