Greenhouse Gas Emissions and Crop Yields From Winter Oilseed Rape Cropping Systems are Unaffected by Management Practices

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.

Emission, sequestration, credit and trading of carbon under gamhar (Gmelina arborea Roxb.) based agroforestry system towards net zero carbon emission of India

“…Because agroforestry have more carbon sequestration potential and lower carbon emission through trees, intercrops and soil; similar results have also been con rmed by 36 reported signi cantly lower net carbon emission ha − 1 in agroforestry system (-40.998 t ha − 1 ) as compared to open farming (-37.263 t ha − 1 ) despite higher emission (1.052 t ha − 1 as compared to 0.998 ha − 1 in open farming) due to more carbon sequestered by trees in the agroforestry system (42.049 t ha − 1 as compared to 38.261 t ha − 1 in open farming). 37 reported that in mustard eld, the CO 2 emission values ranging from 1.083 to 1.683 t C ha − 1 were not signi cantly affected by the crop cultivation treatment. According to 38 the average yearly GHG emissions ranged from 0.93-1.60 t CO 2 e ha − 1 yr − 1 , which may be considered low when compared to other systems, probably due to adoption of agroforestry systems with reduced fuel inputs, land practices, machinery use and CO 2 emissions.…”

Carbon sequestration and credit potential of gamhar (Gmelina arborea Roxb.) based agroforestry system for zero carbon emission of India

“…The carbon stock in herbs and shrub species was determined by multiplying total biomass (above ground + below ground biomass) with carbon conversion factor of 0.45 38 , 39 . …”

Agricultural Land: Crop Production or Photovoltaic Power Plants

“…Its value depends on crop cultivar, practice, climate, etc. For most common crops, carbon dioxide emissions range from 500 to 3200 kgCO 2 /ha (Figure 24) [90][91][92][93][94][95]. The figures reveal that sunflower growing has the smallest carbon dioxide footprint, and corn growing has the highest carbon dioxide emissions.…”