Nourishing cultivated soils with organic fertilisers - 4R Reassurance
Jon Smith - Managing Director, 4R Group
Jon Smith Managing Director

Nourishing cultivated soils with organic fertilisers is an ancient and proven practice to get better growing conditions and crop yields. It’s widely acknowledged that intensive farming methods eventually exhaust the organic fractions within soils, leaving them depleted of plant nutrients, vulnerable to wind and water erosion and a lack of ability to function as a ‘natural’ soil. In 2017, there were 3.9 million hectares of arable land in the UK (Defra, Farming Statistics, 2017), reflecting a nationwide vulnerability which threatens the productivity of our land for future generations.

The organic matter status of a soil is a key indicator of ‘soil health’ and the new UK Agriculture Bill 2017-2019 (HC Bill 266) aims to encourage farming methods which safeguard and promote soil health. In the Bill, farmers and landowners will be paid for ‘public goods’ including improved soil health, which will replace existing Direct Payments.


In recent decades, additional organic materials away from traditional farmyard manures, slurries and dirty water have come onto the market, giving farmers and landowners wider choices for adding organic matter back into their soils. These include utility sludges (biosolids, potable water sludges), composts, anaerobic digestates, paper wastes, manufacturing wastes and others which has developed into a specialist multi-million tonne industry of recycling organics to land.


Whilst farmers continue to utilise on-farm wastes as a priority, market development and appetite for alternatives from the organics recycling industry is on the increase, in particular anaerobic digestates and composts from source-segregated waste streams. These materials are marketed and sometimes sold to farmers on the basis of providing a fertiliser replacement value based on nitrogen, phosphate, potash and sulphur as well as trace elements. For solid materials, the addition of organic matter is generally considered a ‘bonus’, and the true economic value of this valuable benefit has traditionally been overlooked. Given the new focus on soil health and the vital role that organic wastes and products will have in sustaining the organic matter status in our agricultural soils, the value of this benefit is now receiving more attention. A good example of this is Whitemore et al, 2017 published by the Agricultural and Horticultural Development Board (AHDB) which calculates the economics of applying organic matter from different types of amendments across soil types.


As a group, we believe that recycling and recovery of organic wastes and products to land have an important role in sustaining the organic fraction of our heavily cultivated soils. Use of organics also promotes sustainability and forms part of our circular economy. If you wish to talk to one of our FACTS qualified professionals about the health of your soils, please call the 4R Reassurance team on 0345 64 64 314.


Dr. Becky Wheeler – Director, Head of Consultancy, 4R Group