Washington: A combination of waste materials supplemented with a product of biomass could help in the search for high-quality soils, suggests a new study.
The study published in the journal 'Science of the Total Environment', focused on a soil composed of waste materials, which has been deployed to support a variety of plants within natural and artificial environments over an 18-year timescale.
"Manufactured soils are a growing component in the fight for global food security. But for them to be effective and sustainable, they must retain and cycle nutrients without the need for significant fertilizer inputs," said Dr Kate Schofield, lead researcher of the study.
"This study has shown that, by combining waste material with pyrolysed biomass (charcoal), the number of nutrients escaping can be significantly reduced. It is a promising first indication that sustainable soils from waste can be generated and something we are now looking to build on through our current research."
Scientists from the University of Plymouth demonstrated that adding biochar - a solid, carbon-rich material derived from biomass - to soil constructed from waste materials, reduces the loss of essential nutrients such as nitrogen and carbon.
They believed that it can improve the sustainability of manufactured soils by enhancing conditions suitable to sustain plant growth, by improving moisture content, nutrient retention, and carbon storage capacity.
It will also lower the soil's dependence on intensive fertiliser applications, reducing both cost and the risk of pollution from the excessive leaching of nitrogen. However, its success has relied on regular fertiliser applications to supply the required nutrients so the research objective was to measure the effect of biochar application on the retention of macronutrients over the experimental period.
Mineral and organic waste materials, derived from a range of industries and activities, have the potential to be reused as components of manufactured soils. Their uses include the manufacture of topsoils for urban grasslands and as materials for the horticulture, agriculture, amenity, and restoration markets.
