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03 September 2020

A study has found plastic waste to be concentrated more in the earth than the oceans, with the pollution causing significant damage to soil life. Researchers in China found particularly large reductions in creatures that regulate carbon and nitrogen cycling. The authors call for “a reduction in the use of plastics and to avoid burying plastic wastes in soils, as this may bring adverse ecological consequences on soil communities and biogeochemical cycling in terrestrial ecosystems.”

30,000 tonnes of sewage sludge, which includes human waste, will be imported into the UK from the Netherlands (where its use is banned) as farmland fertiliser, a Greenpeace investigation has found – with potential risk of land contamination by microplastics, pathogens, heavy metals and other pollutants. A CEH researcher highlights potential benefits of sewage for farmland, including returning nutrients and building soil structure.

On this theme, a University of Washington researcher has been using ‘soil sniffers’ to develop a soil recipe with the perfect combination of nutrients to improve plant growth. Decomposing materials are toxic to plants and can be identified by people as they emit a smell we register as unpleasant.

Iowa, one of two regional jewels in the crown of US agriculture, is home to mollisol, a famously fertile soil that developed over millennia; but which is currently being lost at 16x the rate of natural replenishment due to the destructive practices of corn-belt agriculture. The suggested solution: “US federal farm policy should stop paying farmers to overproduce corn and soybeans, and instead push them to diversify plantings and keep land covered all winter…preserving soil, decreasing water pollution and slashing the need for pesticides and fertilisers.” 

And an Indiana corn farmer has made records to raise awareness of the lasting impact of soil compaction, demonstrated as negatively affecting the growth of his crops this year. Studies have shown the impact of compaction can be seen up to 3 years after the event, and is exacerbated by extreme weather such as drought.

The first survey to poll producers in the Northern Great Plains is trying to establish how to increase soil conservation practices as part of a 4-year Dep’t of Agriculture-funded project. The lead researchers said “farmers play a key role in preventing and reversing soil degradation. If we can show producers that soil health is important to long term profitability, they will be more likely to adopt these practices.”

Scientists have warned climate change could alter permafrost soil microbes, with currently unknown consequences for arctic ecosystems. The theory is based on the fact that the microbes and chemistry changed dramatically following the last Ice Age – and so could do so again as a result of the current climate crisis.

Lyrebirds are one of the most significant ecosystem engineers as they disturb more soil than any other digging animal, thereby altering or creating altogether new habitats. The birds rake the forest floor, exposing bare earth, mixing and burying leaf litter, while seeking invertebrate prey – moving, on average, 155 tonnes/hectare of soil displaced in these forests.

Britain is one of the most road-dense regions in the world, with enough roadways to wrap around Earth 10x and 80% of land falling within half a mile of a road; yet there has been little effort to mitigate the impact of all this tarmac on wildlife. Whilst studies of the impact on wider biodiversity have yet to be conducted, scientists have recently analysed the effect on birdlife.

Testing the ‘prevention is better than cure’ theory, a farmer in Wiltshire has produced a robust crop of winter wheat using minimal fungicide inputs, due to a sophisticated programme involving targeted nutrition and boosting soil health.