Targeted interventions

The most common interventions in grassland systems are the use of fertilisers and lime. The few field-based studies looking at normal field application rates suggest that there is relatively little direct impact of fertiliser or pesticide on soil organisms in terms of biomass, activity or diversity.  Consequently interventions to reduce or target fertiliser or pesticide use are expected to have relatively little impact on soil organisms, though they may have wider environmental benefits.

Consider the following recommended practices

  • Inoculate legumes through seed treatments if you are growing a non-native species or if legumes have been absent for a long time

There are a number of proposed specific practices often targeted at individual species or functional groups within the soil biota.  These targeted interventions directed at soil organisms, such as the use of compost tea or a microbial inoculant, have largely been developed and studied in controlled conditions and are currently used by small number of farmers.  Where such interventions have been adopted on-farm, they usually form part of a set of changed practices, which include a range of other changes to the management of organic matter inputs and tillage.  Robust data on the distinct effectiveness of most targeted interventions under field conditions is therefore not available. 

Inoculation of specific crops/varieties with targeted rhizobia / mycorrhizal fungi is warranted where the association is obligate – however, this appears to have relatively little direct impact on the indigenous soil organisms.  More general use of AM fungi inocula has been proposed; evaluation to date suggests little effect. 

In a Natural England project (2011-12) expert judgement on the impacts of the practices was linked with farmer feedback on their likely uptake and effectiveness. A summary of the recommended practices for increasing plant diversity on-farm for grassland systems can be downloaded here. Stockdale, E.A. & Watson, C.A. 2012. Managing soil biota to deliver ecosystem services. Natural England Commissioned Report, No. 100.

Related Links & Publications