Topic:  A combined farm-scale survey and experimental study that generated the first direct comparison between conventional and organic management under a mixed farming system in the north-east of England.

  • Newcastle partners: Caio Fernandes Zani, Julia Cooper, Elisa Lopez-Capel, Gavin Hall, Rachel Chapman and William Taylor.
  • Collaborators: Enviresearch Ltd 

Summary:

Different management practices, such as grazing regime (non-grazed vs. grazed), proportions of temporary grass-clover leys in crop rotations (ley time proportion), crop rotation schemes (conventional vs. organic) and fertilisation sources (mineral vs. compost), bring about changes in inputs and outputs of soil organic matter (SOM), soil biodiversity, nutrient cycling, C distribution within SOM pools, molecular composition of SOM and consequently affect soil quality as well as soil C stocks and stability. It is, however, still unclear how those variables would affect the provision of ecosystem services from agricultural soils. This disparity may be due to the lack of comparisons considering more than one driver of change, i.e. not only the agricultural system as a whole but also taking into account the interactions between the systems and core practices (e.g. crop rotation schemes and fertility sources). Additionally, information on distinctive management practices, such as the proportion of grass-clover leys in arable rotations, amount of manure applied, and whether ley periods are used for hay meadow cutting or livestock grazing (i.e. non-grazed vs. grazed), have seldom been considered in previous studies. Lastly, previous studies comparing conventional vs. organic systems have only examined the change in topsoil, but comparable research has demonstrated that soil C in subsoil layers (i.e. > 0.20 m) must also be included. Such aspects are essential for a more holistic soil C stocks assessment under different agricultural systems and if they are not taken into account the results can be misleading. The results of this study can contribute to ongoing efforts to improve the current agricultural systems and management practices, and delivery of a more sustainable agriculture sector, which might be able to mitigate the expected climate change while contributing to soil health and food security aspects.