Determining the effects of tillage and nitrogen sources on soil N 2 O emission

Soil N2O emissions with different reduced tillage methods during the establishment of Miscanthus in temperate grassland

“…The water-filled pore space in our study was in the optimum range for N 2 O emissions (~80%; Butterbach-Bahl et al, 2013;Maag & Vinther, 1996), and rainfall at the site was above the UK national average which may in part have also contributed to the higher fluxes and highlights the need for more work across a range of climatic conditions. Whilst N 2 O fluxes can vary between years (Drewer, Finch, Lloyd, Baggs, & Skiba, 2012;Jorgensen, Jorgensen, Nielsen, Maag, & Lind, 1997), the trend for a reduction in the second year after establishment seen in this experiment (despite higher second year early season fluxes) is in line with Roth et al (2013) and fits with the generally low fluxes reported for mature Miscanthus plantations in studies by Gauder, Butterbach-Bahl, Graeff-Hönninger, Claupein, and Wiegel (2012) and Drewer et al (2012). This suggests that fluxes in mature crops are likely to be lower than those recorded here for the conversion period, a point also noted in review by Whitaker et al (2018).…”

“…However, there are other benefits from no till planting to be considered, such as reduced soil erosion and the retention of soil organic matter (Holland, ; Lal et al, ). Whilst no till cultivation can sometimes increase N 2 O emissions compared to conventional tillage in wet and poorly aerated soils (Grave et al, ; Rochette, ), we found no significant difference between the low impact cultivation methods tested.…”

“…Models predicted around 40% of the variance, values higher than those reported by Roth et al (2013), where only 27% of fluxes could be explained by a large number of factors and Gauder et al (2012) where soil temperature explained less than 10%. N 2 O fluxes are known to be volatile so higher frequency monitoring of N 2 O fluxes (in this study once every 2 weeks) with chambers, or continuous monitoring with the capture of larger ground areas via eddy covariance methods may reveal more about N 2 O drivers (Alves et al, 2012;Jones et al, 2011).…”

“…Reduced tillage methods involving either planting directly into the soil without any form of ploughing (no till) or minimum tillage (cultivation to a shallow depth generally not more than 10 cm) are generally recognized to have the benefits of reduced soil erosion and water runoff and can lead to increases in soil organic matter and soil biological activity (Holland, ; Lal, Reicosky, & Hanson, ). However, the impact of no till cultivation on N 2 O emissions can vary and seems to be linked to soil type and water content (Chatskikh & Olesen, ; Grave et al., ; Rochette, ). The use of a bio‐degradable film mulch has shown improved agricultural and economic performance of Miscanthus by increasing shoot density during establishment in cool temperate climates through increased soil temperature and conservation of moisture (Ashman, Awty‐Carroll, Mos, & Robson, ; Olave et al, ).…”

How Tillage and Fertilization Influence Soil N2O Emissions after Forestland Conversion to Cropland

“…The stepwise regression analysis results indicated that soil WFPS and temperature could explain 82% of the variations in N 2 O fluxes from forestland (Table 4). Soil temperature and moisture are important factors that influence soil N 2 O emissions by affecting microbial activities [8,23,44]. The low soil moisture and temperature during the winter wheat season (Figure 2) generally inhibited microbial activities, resulting in low N 2 O emissions [3,11].…”