Controlled traffic farming effects on soil emissions of nitrous oxide and methane

Full description

Soil compaction affects soil aeration and gas diffusivity, and thus has a major impact on the release of greenhouse gases (GHGs) from fertilised soils. Controlled traffic farming (CTF) systems reduce the area of compacted soil by confining all field traffic to permanent traffic lanes, and a pilot trial at one long-term CTF site provided evidence of reduced soil emissions. We investigated the effect of CTF on soil emissions of nitrous oxide (N2O) and methane (CH4) using replicate manual chamber measurements in 3 traffic treatments;namely:non-trafficked CTF beds, permanent CTF lanes,and a single traffic pass on CTF beds to simulate the random traffic tracks of non-controlled traffic farming. Emissions of N2O and CH 4 were monitored from these treatments in 15 crops over 3 years on 6 grain farms in Queensland, Victoria and Western Australia.
Thus, the major objective was to determine the emissions of N2O and CH4 from random trafficked and permanent traffic lane soil, relative to those from non-trafficked CTF beds. These emission ratios are referred to here as traffic impact factors.