Less intensively managed grasslands have greater plant diversity and better soil health, research shows for the first time

The study shows that less intensively managed grasslands have greater plant diversity. Pictured are cows feeding in a pasture in Arnside, Cumbria. Credit: Markus Wagner

Researchers have shown – for the first time – that less intensively managed British grasslands have on average 50% more plant species and better soil health than intensively managed grasslands. The new research could help farmers increase both biodiversity and soil health, including the amount of carbon in the British countryside’s soil.

Grassland makes up a large part of the British countryside and is vital to agriculture and rural communities. This land may only be thought of as a place to produce food, but this study provides more evidence that it can be key to increasing biodiversity and soil health.

Researchers from the UK Center for Ecology and Hydrology (UKCEH) studied 940 grasslands, comparing randomly selected plots that sampled across the range of rangeland management in Great Britain; from intensively managed land with few sown pasture species and high soil phosphorus levels (indicating ploughing/reseeding and fertilizer and liquid manure applications), to pastures with higher species levels and lower soil phosphorus levels. Plots were sampled as part of the UKCEH Countryside Survey, a nationally representative long-term data set.

The study counted the number of plant species in the sample areas and analyzed co-located soil samples for soil invertebrate numbers and levels of carbon, nitrogen and phosphorus.

The researchers found that less intensively managed pastures had a greater diversity of plant species and, strikingly, this correlated with better soil health, such as increased nitrogen and carbon levels and increased numbers of soil invertebrates such as springtails and mites.

In the same study, researchers used the same methods to examine the plant diversity and soil of pastures on 56 mostly beef farms from the Grassland Livestock Association (PFLA), a farming group that has developed standards for managing and improving soil and pasture health.

The researchers found that plots of land from PFLA farms had greater plant diversity—an average of an additional six plant species, including different types of grasses and herbaceous flowering plants—compared to intensively cultivated plots from the Country Study. In addition, the pasture plants on these farms were often taller, a quality that has been shown to benefit butterflies and bees.

The Grassland Association’s grasslands have not yet shown increased soil health, but the study suggests that this may be due to a time lag between increasing numbers of plant species and changes in soil health, particularly on farms that have been intensively managed in the past.

Lead author Dr Lisa Norton, senior scientist at UKCEH, said: “We have shown for the first time, on land managed by farmers for production, that greater plant diversity in grassland is associated with better soil health. This work also tells us that Pasture Fed members are on the right track to increase biodiversity, although it may take longer to see improvements in soil health.

“Grasslands with diverse plant species capable of growing tall and flowering are associated with improved measures of soil health and are beneficial to creepy-crawlies below and above ground. Having this abundance of life in our grasslands can in turn support small mammals and birds of prey, and farmers have told us they are seeing voles and mice in their fields for the first time.”

Dr Norton adds: “My hope for the future is that our rangelands can be managed less intensively – with all the improvements in plant and animal biodiversity and soil health that bring – but still remain productive for farmers .”

The study was published in the journal Environmental solutions and evidence on November 25, 2022

More info:
Lisa R. Norton et al, Can grazing livestock practices improve the ecological status of UK grasslands?, Environmental solutions and evidence (2022). DOI: 10.1002/2688-8319.12191

Courtesy of the British Center for Ecology and Hydrology

Quote: Less intensively managed grasslands have greater plant diversity and better soil health, study shows First (November 25, 2022) Retrieved November 25, 2022, from https://phys.org/ news/2022-11-intensively-grasslands-higher-diversity-soil.html

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