The Use of Biosolids and Other Organic Substances in the Creation of Soil‐Forming Materials

Abstract

Abstract This paper describes an experiment which was carried out at a landfill site in north Lincolnshire to investigate the use of biosolids and other organic materials in soil formation. The following organic amendments were incorporated into the surface of the on‐site geological clay to form ‘topsoil’treatments: (i) nil, (ii) biosolids (digested cake), (iii) waste peat/compost, and (iv) composted green waste. The biosolids were applied at a rate of 70 tDS/ha and all the organic materials were incorporated to a depth of 150 mm. The organic amendments reduced the topsoil bulk density and increased plant available water supply and soil water infiltration rates. Topsoil organic matter, total nitrogen and extractable phosphorus concentrations, biomass nitrogen, readily mineralisable organic nitrogen and soil respiration rates were also increased. Additionally, the biosolids application increased topsoil aggregate stability and soil surface strength.