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A validation of an extended critical state model was conducted using a heavy agricultural clay soil from Quebec Province, eastern Canada. The numerical model used for this purpose simulated the behaviour of Sainte-Rosalie clay under triaxial compression and one-dimensional compression loading paths. Under triaxial compression, simulations were done for three soil suctions: 0, 300, and 500 kPa. Under one-dimensional compression, simulations were done for suctions 0 and 300 kPa. The model used five parameters while simulating soil mechanical behaviour under saturated condition. Three additional parameters were required for simulating soil mechanical behaviour under unsaturated condition. Results of simulations were then compared to those of laboratory tests. Experimental data compared well with simulation results. It was found that the model reasonably predicted soil behaviour under both saturated and unsaturated conditions. However, some discrepancies arose in both soil conditions: the model predicted an earlier rupture in each case of triaxial compression and it failed to reach the smallest void ratio obtained during one-dimensional compression. These small divergences were attributed to the fact that numerical development of the tested model was based on densified sand behaviour. [Copyright &y& Elsevier]

• Reduced tillage increased growing season N 2 O emissions on fine textured soils. • Fertilization with dairy and pig slurry resulted in similar N 2 O emissions. • Nitrous oxide emissions were lower from the coarse compared to fine textured soil. Reduced tillage is often promoted as a method to sequester carbon (C) in soils and thus mitigate climate change. However, in certain conditions reduced tillage may increase soil nitrous oxide (N 2 O) fluxes, which may negate any climate gains from the potential storage of C in soil. To investigate how long-term applications of different manures interact with tillage effects on N 2 O fluxes during the crop rotation, we established a long-term trial in 2009 in eastern Canada, using two tillage (inversion tillage [IT]; and reduced tillage [RT],) and three fertilizer types (pig slurry, dairy slurry and a 0-N control) arranged in a split-plot design with 3 replications. The experiment was reproduced on two contrasting soil textures (silty clay and sandy loam) located approximately 900 m apart in a wheat-corn-soybean rotation. During 2016 (wheat), 2017 (corn), and 2018 (soybean) we estimated the N 2 O fluxes from each plot using manual static chambers for the growing season (April to November). Mean cumulative fluxes for the growing season ranged from 0.8 kg N 2 O-N ha−1 for the corn/control/IT to 7.6 kg N 2 O-N ha−1 for the wheat/dairy slurry/RT in the silty clay soils and from 0.4 kg N 2 O-N ha−1 for the corn/control/IT to 3.0 kg N 2 O-N ha−1 in the corn/pig slurry/RT in the sandy loam soils. The RT increased soil N 2 O fluxes for both slurry types and the control in the clay soil (mean flux for all fertilizer treatments over both seasons were 5.5 and 2.4 kg N 2 O-N ha−1 season−1 for the RT and IT, respectively), likely because the higher water content in the RT caused greater denitrification; while on the sandy loam the N 2 O flux was similar between the two tillage systems. Manure type had no measurable effect on the growing season N 2 O fluxes in either soil type as both provided sufficient labile N. Application of both slurries however, resulted in greater emissions than the control (P = 0.002). These findings suggest that RT on fine-textured soils in this region may not be an effective strategy to reduce GHG emissions. [ABSTRACT FROM AUTHOR]