Abstract
Winter oilseed rape is traditionally established via plough-based soil cultivation and conventional sowing methods. Whilst there is potential to adopt lower cost, and less intensive establishment systems, the impact of these on greenhouse gas emissions have not been evaluated. To address this, field experiments were conducted in 2014/2015 and 2015/2016 to investigate the effects of 1) crop establishment method and 2) sowing method on soil greenhouse gas emissions from a winter oilseed rape crop grown in Ireland. Soil carbon dioxide, nitrous oxide and methane emission measurements were carried out using the static chamber method. Yield (t seed ha−1) and the yield-scaled global warming potential (kg CO2-eq. kg−1 seed) were also determined for each management practice. During crop establishment, conventional tillage induced an initially rapid loss of carbon dioxide (2.34 g C m−2 hr−1) compared to strip tillage (0.94 g C m−2 hr−1) or minimum tillage (0.16 g C m−2 hr−1) (p < 0.05), although this decreased to background values within a few hours. In the crop establishment trial, the cumulative greenhouse gas emissions were, apart from methane, unaffected by tillage management when sown at a conventional (125 mm) or wide (600 mm) row spacing. In the sowing method trial, cumulative carbon dioxide emissions were also 21% higher when plants were sown at 10 seeds m−2 compared to 60 seeds m−2 (p < 0.05). Row spacing width (125 and 750 mm) and variety (conventional and semi-dwarf) were found to have little effect on greenhouse gas emissions and differences in seed yield between the sowing treatments were small. Overall, management practices had no consistent effect on soil greenhouse gas emissions and modifications in seed yield per plant countered differences in planting density.
Highlights
Atmospheric concentrations of the greenhouse gases (GHG) carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) continue to rise globally due to anthropogenic activities
Cropland management practices that involve the adoption of less intensive soil cultivation and agronomic interventions that improve agricultural productivity may can lead to reductions in GHG emissions and determine whether these ecosystems function as sinks or sources of C (Ceschia et al, 2010)
Management practice had a minimal effect on GHG emissions, crop yield and yield scaled global warming potentials (GWP)
Summary
Atmospheric concentrations of the greenhouse gases (GHG) carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) continue to rise globally due to anthropogenic activities. Agriculture is responsible for approximately 12% of global GHG emissions with livestock systems, soil cultivation, rice production and crop residue management making the more significant contributions (Ciais et al, 2014). In terms of land use impacts, croplands make one of the major contributions to agricultural GHG emissions through various farming and management activities. GHGs Under WOSR Management Practices such as soil tillage, sowing, fertilizer addition and chemical treatment that are normally required to maximize plant productivity and yield can have significant impacts on GHG emissions through perturbations in the carbon (C), nitrogen (N) and water dynamics of these ecosystem (Bondeau et al, 2007; Osborne et al, 2010). Cropland management practices that involve the adoption of less intensive soil cultivation and agronomic interventions that improve agricultural productivity may can lead to reductions in GHG emissions and determine whether these ecosystems function as sinks or sources of C (Ceschia et al, 2010)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
