At Terravesta, we’ve been speaking to Prof Angela Karp and Dr Alison Haughton from Rothamsted Research, the longest running agricultural research station in the world, to find out about a study that’s been conducted into the benefits miscanthus can have on farm biodiversity.
Growing perennial bio-energy crops such as miscanthus, and short rotation coppiced (SRC) willow, on land previously cultivated under annual rotational arable cropping, can reinstate landscape biodiversity.
And, what’s more, the operational benefits of this biodiversity are greater than the field the crop is growing… meaning neighbouring fields will benefit as well.
This is according to a scientific article recently published by Rothamsted research scientists, one that’s looked into the impact biomass crops have on biodiversity across arable landscapes.
“Growing both miscanthus and SRC willow can bring clear biodiversity benefits to arable farmland that’s continuing to lose important species,” says Dr Alison Haughton, the scientist who led the study.
The study findings show that integrating dedicated biomass crops into an arable system results in significant, large-scale changes to the abundance of, and composition of, plants and invertebrates, some of which have a direct impact on ecosystem function and health.
“There’s a magnitude of difference between the numbers of invertebrates that are present in bio-energy crops compared with arable crops. At the very least there were four times as many individuals found on test sites, and at the most we found 38 times more, all contributing to the biodiversity of the surrounding landscape, as many of these invertebrates are important sources of food for wildlife groups such as birds,” says Dr Haughton.
The study shows that there’s a huge increase in the presence of detritivores, which feed on dead organic material in the soil, contributing to decomposition and nutrient cycles.
“We also found that there’s a greater abundance of seeds that have been incorporated into the soil. This is because miscanthus, and SRC willow, are harvested in late winter/spring time, and the seeds from the wildflowers growing within the crop have already been incorporated into the soil. Whereas with arable crops, the wildflower seeds are removed with the harvest.
“Seeds are an important resource for birds, and for insects like ground-beetles, which are also natural predators of crop pests, and countless other animals. Seeds will grow into wildflowers that will again benefit the ecology of the landscape.”
The co-existence of wildflowers with crops is very important to species like butterflies, and also bees, who need appropriate food sources to establish colonies for the year ahead, as well as throughout the year.
“Miscanthus and SRC willow growers use wide headlands around the crop, and these provide a really important habitat and food resource for butterflies, bees and other species,” says Dr Haughton.
“The reason that crops such as miscanthus and willow offer an ideal habitat for a number of beneficial plants and species is primarily because of a lack of disturbance to the soil. Once planted, the soil may be uncultivated, with miscanthus harvested annually and willow coppice in three-year harvest cycles.
“Essentially the soil will not be cultivated for in excess of 15 years with miscanthus and SRC willow and this allows the development of communities of plants and invertebrates that rely on low levels of disturbance to thrive in otherwise heavily disturbed, annually cultivated arable farmland. Diversifying crops grown on farmland, with a mixture of perennial and annual crops helps to contribute to landscape biodiversity,” adds Dr Haughton.
Professor Angela Karp who leads the Cropping Carbon strategic programme of research supported by the BBSRC at Rothamsted Research underlines the key message from the study: that diversity of crops leads to diversity of wildlife.
“We’ve found that managing agricultural landscapes in a sensitive and appropriate way, by introducing a diversity of crops, can really enhance the surrounding ecosystem, and this can simultaneously work towards striking a balance between energy and food security,” says Prof Karp.
“We know there’s an on-going issue with the loss of biodiversity from farmland, and we know there needs to be a balance between food and energy production. But what this study shows is that planting less productive land with non-food bioenergy crops, such as miscanthus or SRC willow, can actually bring multiple benefits into the surrounding landscape, and other crops.”
Angela is also overseeing a number of other projects that look into the impact bioenergy crops have on the surrounding environment.
“We’re looking at soil carbon changes under energy crops, and we’ve found that if the miscanthus crop is well managed, it may not take long to reinstate the level of carbon accumulation under grassland and it will certainly exceed levels of carbon present under cereals. Even though grown under low input agriculture, miscanthus achieves soil carbon levels similar to high input arable farming.
“As well as this, we’re exploring how to get more value from bio-energy crops, and how we can exploit the chemistry they generate. There’s a diversity of compounds that these crops make, that potentially have a pharmaceutical value,” says Prof Karp.
Rothamsted collaborates closely with Aberystwyth University, who have also conducted various trials into miscanthus, such as seeing how the crop copes with growing on flood prone land during its establishment, and the benefit it offers to the soil. There are breeding programmes for both crops, including a seed breeding programme for miscanthus at Aberystwyth.
“It’s important to invest in research and development into miscanthus and SRC willow because, without these crops, we’ll struggle to meet climate change targets we’re signed up to for 2020, 2030 and 2050, and our farmers are a crucial part of the binding effort to tackle climate change, that was agreed in the Paris climate change summit only this month. Farmers’ decisions on which crops to cultivate on which land should be supported by the most up-to-date scientific evidence.
“Dedicated biomass crops have multiple, much needed, environmental benefits, and we should be shouting about them from the rooftops to farmers, as well as policy and decision makers,” adds Prof Karp.
For the full study on ‘Dedicated biomass crops can enhance biodiversity in the arable landscape, Global Change Biology Bio-energy’, see: http://onlinelibrary.wiley.com/doi/10.1111/gcbb.12312/full
