Working across the midlands in conjunction with Severn Trent Water, Wrights of Twycross co-ordinate the sales, delivery and application of over 600,000 tonnes of biosoilds to agriculture each year.

What are biosolids?
Biosolids have been in use in UK and European agriculture for over forty years. Biosolids are a by-product of the treatment of wastewater produced by human activity, e.g. domestic housing, schools and factories. Biosolids are derived from living “cultures” of microorganisms (mainly bacteria) that help to purify the wastewater during treatment processes at the sewage works and before it is returned to rivers or the sea. As a result, biosolids contain substantial quantities of nutrients and organic matter which can be used by farmers to meet crop nutrient requirements and to maintain soil fertility. Biosolids recycling is a safe, sustainable, highly regulated and environmentally sound solution to the increasing challenge of nutrient cycling and byproduct management.

Biosolids – good for your land, good for your business
The benefits to the land and the farm business are substantial and include the following:

  • A valuable source of major plant nutrients, nitrogen, phosphorus, sulphur, magnesium
  • Organic matter additions provide a soil conditioning effect and increase moisture retention
  • Trace element additions
  • Material from some treatment plants contain a high lime content
  • Detailed analysis of the biosolids and advice are provided
  • The service, at present, includes soil analysis (nutrient status and metals content) for each field treated
  • Biosolids are spread only by approved contractors to ensure accuracy and care.

Types of biosolids available to agriculture
Digested cake and digested liquid have traditionally been the products most commonly applied to farmland. In recent years, however, there has been an increase in the production of lime treated or conditioned biosolids products. These biosolids products all meet the treatment requirements defined within the Safe Sludge Matrix for application to agricultural land. Biosolids are a very valuable source of the major plant nutrients, nitrogen (N), phosphorus (P), sulphur (S) and magnesium (Mg). Based on the analysis of a large number of samples, typical nutrient contents of the main biosolids types are shown in Table 1.