Denitrification in tillage and no tillage pampean soils: relationships among soil water, available carbon, and a nitrate and nitrous oxide production
1995
Rodriguez, M.B. | Giambiagi, N.
The interactions among the denitrification (DN) regulating factors under no tillage (NT) and conventional tillage (CT) during the production of a wheat crop were studied. The usefulness of the water field pore space (WFPS) as an indicator of the magnitude of the nitrous oxide (N2O) losses under the two tillage methods was also analyzed. The N2O production, mineralizable carbon (MC), WFPS, and nitrate (NO3) content were measured in a typic argiudol. The NT system increased N2O losses by DN at the 0-10 cm sampling depth because of its action on the MC and WFPS. Denitrification correlated significantly with the WFPS (r = 0.6, p<0.01), MC (r = 0.69, p<0.01), and NO3 content (r = 0.37, p<0.05). The influence of these factors on denitrification explained 55% of the differences between tillage methods, and as a consequence, we would suggest another possible influence of other factors not considered in this investigation. The addition of fertilizer (urea) would result in an increase in DN losses with neither tillage method. Regarding the relation between WFPS and N2O losses, we found that the CT plots had WFPS values <42% and on the NT plots WFPS values were >42%. This means that from 42% WFPS, the difference in N2O losses between the two tillage methods were significant in this pampean soils.
显示更多 [+] 显示较少 [-]