The use of paper crumble for soil enhancement and carbon storage
Evidence suggests that UK arable soils have been losing carbon for 40 years (Environment Agency, 2019). This contributes significantly to the country’s CO2 emissions. This in turn presents a challenge to the current conventional cultivation of arable farmland, as it has been observed to have detrimental effects on the ecosystem and structures within soil.
Paper crumble can be used to enrich soil, giving arable farmland a boost of nutrients and organic matter. Paper crumble is a by-product of the papermaking and recycling industries. While some is used for animal bedding, hundreds of thousands of tons of it are typically sent to landfill or incinerated. Although paper crumble has been used in soil in the UK for over 15 years (Gibbs et al., 2005), there has so far been very little research into its benefits.
Researchers at University of East Anglia (UEA), led by Professor Brian Reid, found paper crumble to have wide reaching effects. The team explored the potential of paper crumble as a means to enrich soil, improving the retention of water and nutrients, and therefore demonstrating benefits to the health of soil and crops overall. The project also highlights how paper crumble can be used as a tool to store carbon within agricultural soils. This is in line with the goals of “4 per 1000”, an initiative which aims to adapt agriculture to the concerns of food security and climate change (Soussana et al., 2019).
The Challenge
The current processes by which arable farmland is cultivated leads to the depletion of soil organic carbon (SOC) (Lal, 1992; 2001). SOC is integral to the formation and fertility of soil aggregate. If depleted, the cohesion of the soil is reduced, increasing its vulnerability to erosion and allowing aggregate breakup. This negative effect on soil structure also increases the risk of mineral and nutrient losses from the soil, greatly reducing soil fertility. Therefore, the importance of maintaining a high soil organic carbon content to maximise crop performance is clear.
The Approach
With EIRA funding, UEA researchers teamed up with Greenworld Sales Ltd (a recycling and waste management company based in Norfolk) to collect and analyse soil samples. The samples were taken from a number of fields where varying levels of paper crumble had been added. They were assessed by chemical, physical and biological methods, followed by data analysis. Soil carbon content, soil nitrogen content, soil nutrient content, water holding capacity and infiltration, soil density and crop yield determination were all measured, with benefits evaluated.
The Outcome
The outcome of this investigation has shown that by increasing soil organic carbon, paper crumble has the potential to rejuvenate soil. The stability of soil structure is improved, the nutrient supply to crops is enhanced, and carbon can be stored with greater efficacy. Results from the field study confirm that paper crumble will provide long-term significant increases in SOC, enhance nutrient supply and improve food security.
Adding paper crumble to soil will also increase its chemical, physical and hydrological quality. Combined with further field studies, these findings will provide compelling evidence for the use and incorporation of paper crumble as an important soil improver. Furthermore, these results will provide additional evidence for how paper crumble can aid in the delivery of national and international targets to build recalcitrant SOC stocks in agriculture.
Sources
Environment Agency (2019) The State of the Environment: Soil. Available here
Gibbs, P.et al., (2005) Landspreading on agricultural land: nature and impact of paper wastes applied in England and Wales. Science Report SC030181/SR, Environment Agency, Bristol.
Lal, R. (1993). Tillage effects on soil degradation, soil resilience, soil quality, and sustainability. Soil and Tillage Research, 27(1-4), pp.1-8.
Lal, R. (2001). Soil degradation by erosion. Land Degradation & Development, 12(6), pp.519-539.
Soussana, J. et al., (2019). Matching policy and science: Rationale for the ‘4 per 1000 – soils for food security and climate’ initiative. Soil and Tillage Research, 188, pp.3-15.
