New research on soil fertility management
In a recent study by Wageningen University & Research Centre, management interventions to increase the supply of organic carbon were tested with a linear programming model called NutMatch. NutMatch was applied to crop rotations with different mixtures of organic cattle slurry, pig slurry or compost, or with a mineral fertiliser. The study found that rotational crop residues, cattle slurry and compost each substantially contributed to soil organic carbon accumulation (range 200-450 kg C ha-1 yr-1); contributions of pig slurry and cover crops were small (20-50 kg C ha-1 yr-1). In terms of greenhouse gas emissions, it appears that the trade-offs between carbon inputs and emissions of greenhouse gases (notably N2O) or other pollutants (NO3, NH3) can be substantial.