Ploughing on regardless?

Earthworm populations have collapsed under conventional management practices in agriculture. This is linked to a combination of intensive tillage (habitat disturbance), poor organic matter management (food supply interruption) and agro-chemical exposure (low fertility). This is a problem because earthworms are soil ecosystem engineers. Earthworms provide many soil ecosystem services including improving inorganic nutrient bioavailability, reduce Take-all and Fusarium disease incidence and severity, improving soil water balances, carbon sequestration, disperse beneficial soil bacteria and promote legume nodulation. Soils are vital to humankind, but are being rapidly degraded. The UK agri-tech strategy has identified that soil degradation and biodiversity loss threatens soil security. Thus, restoring and managing earthworm resources are vital to soil security in agriculture.

This 'Ploughing on regardless?' fellowship has two goals. Firstly to test a model agro-ecosystem based on a clover-residue-wheat management strategy to rapidly rejuvenate and maintain elevated earthworm populations. The Rothamsted long term experiment trials will be used to inform crop rotations and local minimum tillage farmers network to inform on seasonal changes to earthworm abundances. A novel bio-indicator technique based on midden counting will be developed and used for this goal. Secondly, investigations into combinations of treatments that amplify earthworm benefits to soil security and soil use in agriculture will be performed. These include wheat-cultivar earthworm interactions, earthworm mediated below-ground interactions and earthworm mediated below-ground/above ground interactions to provide a holistic understanding of minimum tillage agro-ecosystems.

These field and laboratory study outcomes will be used to provide guidance on earthworm-centred, minimum tillage farming practices. Further, provide a scientific understanding of how earthworm, AMF and fertiliser interacts to deliver below-ground ecosystem services, and the role earthworms can play in residue incorporation that affect above-ground interactions.

The research proposed is closely aligned with the NERC Soil Security research program, and aims to inform agricultural land managers and policy makers, whilst complementing existing Soil Security grants.

Agricultural Land Managers - Ploughed agricultural land is a simple farming system requiring little land management planning, and crop yields are dependent on inputs. Development of 'no plough' approaches are required in order to manage residues and rotations, and minimise problems with nutrient availability, infiltration, pest and weed problems. A reduction in ploughing would result in escalation of the importance of the natural plough action of earthworms, which are essential to a functioning agro-ecosystem. The novel work packages proposed in this project provide a unique opportunity to track the improvements in earthworm populations, changes in soil quality and yield responses. The ultimate aim is to use soil ecosystems to reduce dependence on inputs (diesel for tillage, mineral fertilisers, agro-chemicals) to improve the sustainability of cereal agriculture.

Policy Makers - soils are vital to humankind, but they are being rapidly degraded. The UK Government Agri-tech Strategy identifies soil degradation and biodiversity loss as a threat to food security, and plans to safeguard soils within the next 15 years. The loss of soil ecosystem engineers for conventionally managed agro-ecosystems is thus critical to this policy, and the outcomes from this project potentially high impact to soil security in agriculture.

An increase in earthworm densities is associated with improved infiltration, which could reduce surface run-off and erosion, and provide benefits to water management at catchment scales (water companies, general public benefit from reduced flooding).

An increase in soil biodiversity (i.e. earthworm populations) could improve the soil web within agro-ecosystems by providing food for birds and mammals. This could improve the quality of life for the general public who use rural areas for recreation activities e.g. bird watching. Identifying partnerships between crops and earthworms would provide potential opportunities to study the pathways responsible, which could lead to commercial opportunities in crop breeding or earthworm products.