Recycling nutrient-rich industrial waste products enhances soil, reduces carbon: Study

A new study suggests that recycling biotechnology byproducts can enhance soil health while reducing carbon emissions and maintaining crop yields.

In a recent paper in Agrosystems, Geosciences & Environment, researchers examine the possible benefits of a new kind of crop fertiliser. They studied two fields of maize -- one plot treated with heat-inactivated spent microbial mass (SMB), and one plot treated with a typical farmer fertiliser practice.

SMB is a biotechnology waste by-product that can provide nutrients contained in conventional fertilisers. Over the course of one year, researchers measured the net ecosystem exchange of carbon dioxide (net CO2 emissions) between the crop surface and atmosphere of the two plots. Researchers also measured yields of maize over two growing seasons, in addition to changes in soil carbon over 1.7 years.

According to the research findings, the addition of SMB provided similar crop yields to that of typical farmer fertilisation practices. However, the SMB had to be applied at greater rates.

The team also found the annual net ecosystem exchange of carbon dioxide was greater for the SMB application than for the farmer practice plot, although some excess emissions appear to be recycled back into the ecosystem.

"The greater application of SMB shows the potential to enrich ecosystem productivity and environmental sustainability through the conversion of waste nutrients into greater yields, greater plant biomass and increased soil carbon," the paper's authors suggest.

Overall, the research found that utilising carbon-rich waste nutrients increases soil organic matter, improves the physical and chemical properties of the soil, and creates a reservoir of plant nutrients, providing environmental and agricultural benefits that extend beyond the immediate application and harvest yield.