title: [Factors influencing ammonia volatilization in a winter wheat field with plastic film mulched ridges and unmulched furrows].
abstract: The objective of this experiment was to quantify ammonia volatilization from a winter wheat field with plastic film mulched-ridges and unmulched-furrows (PMRF). The trial was conducted during the 2010-2011 winter wheat growing season at Yangling, Shaanxi Province. Ammonia volatilization from the soil was measured using the closed-chamber method. The results indicated that NH3 emission losses ranged between (1.66 +/- 0.3) and (3.28 +/- 0.51) kg x hm(-2) in the PMRF treatment. In comparison, the NH3 emission loss was (4.68 +/- 0.35) kg x ha(-1) in the conventional tillage treatment (i. e., smooth soil surface). The PMRF treatment reduced NH3 emissions by 29.8 to 63.8% compared with the conventional treatment. The NH3 emission losses were equivalent to 1.9% of the applied N in the conventional practice treatment. In contrast, the losses were equivalent to only 0.3% to 0.8% of the applied N in the PMRF treatment. Ammonia emissions were greatest during the first two weeks after sowing. Emissions before winter accounted for 82% of total NH3 emission in the conventional practice treatment, but only 49% to 61% of the total NH3 emission in the PMRF treatment. The soil NH4+ -N content and the soil moisture content had direct effects on NH3 emission before winter in the conventional treatment. In thePMRF treatment, the soil NH4+ -N content had a direct effect on NH3 emission before winter, whereas soil surface temperature and soil moisture had indirect effects. Ammonia emissions after the greening stage were mainly influenced by the soil NH4+ -N content. Simulation results indicated that logarithmic functions best described cumulative NH3 emission in the PMRF + high N rate treatment and the conventional treatment. A linear function best described cumulative NH3 emission in the PMRF + low N rate treatment and the unfertilized treatment. In conclusion, the PMRF treatment can significantly reduce N losses from winter wheat fields by changing the spatial-temporal dynamics of soil NH3 volatilization.
authors.affiliation: College of Resources and Environment, Northwest A & F University, Yangling 712100, China. 1987329002@nwsuaf.edu.cn
authors.forename: Yu-Xian
authors.initials: YX
authors.lastname: Shangguan
authors.forename: Ri-Peng
authors.initials: RP
authors.lastname: Shi
authors.forename: Na
authors.initials: N
authors.lastname: Li
authors.forename: Kun
authors.initials: K
authors.lastname: Han
authors.forename: Hui-Ke
authors.initials: HK
authors.lastname: Li
authors.forename: Lin-Quan
authors.initials: LQ
authors.lastname: Wang
mesh_terms: D000383:Agriculture / Q000379:methods*; D000641:Ammonia / Q000032:analysis* / Q000737:chemistry; D004780:Environment, Controlled; D005308:Fertilizers; D014908:Triticum / Q000254:growth & development*; D014835:Volatilization
chemical_list: D005308:Fertilizers; D000641:Ammonia