| Autor: |
Sato, Juliana, Carvalho, Arminda, Figueiredo, Cícero, Coser, Thais, Sousa, Thais, Vilela, Lourival, Marchão, Robélio |
| Zdroj: |
Nutrient Cycling in Agroecosystems; May2017, Vol. 108 Issue 1, p55-68, 14p |
| Abstrakt: |
Integrated crop-livestock systems have been recently adopted in several agricultural regions of Brazil. Studies involving the effect of adopting integrated systems on greenhouse gas mitigation are essential for choosing sustainable agricultural systems. In this study, the emissions of nitrous oxide in a crop-livestock system (4-year crop/pasture rotation) compared with two continuous crop (CC) areas under conventional and no-tillage management were investigated. The treatments consisted of continuous cropping under no-tillage (CC-NT), continuous cropping with annual heavy disc harrow (CC-CT), an integrated crop-livestock system under no-tillage (CLS-NT) and native Cerrado as a reference. Considering the cumulative NO emissions in a year, the CC-CT emitted 2.55 kg N-NO ha, higher than the Cerrado, which emitted 0.55 kg N-NO ha. All the agricultural systems emitted more NO than the Cerrado, however, the two conservation systems CC-NT and CLS-NT had lower emissions than the CC-CT, and were responsible for 1.90 and 1.52 kg N-NO ha, respectively. In the agroecosystems, the highest NO fluxes were observed after fertilization and rainfall events. In the CC systems, NO emissions were greater than in the integrated system during the sorghum/off-season period, but in the CC-CT emissions were greater than in CC-NT. During the soybean cycle no differences in emissions were observed between both CC systems, which surpassed that in CLS-NT that was occupied by Brachiaria pasture. The annual cumulative NO emissions in CLS-NT were close to that observed in the Cerrado indicating this system to be an agricultural practice with potential to mitigate NO emissions. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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