Growing the right grasses

Grasses that reduce greenhouse emissions from cattle, provide efficient sinks for carbon, increase drought resistance, improve soil structure and soil water retention, are available currently or are near to market.

Mike Humphreys is the Grasses Traits and Varieties team leader at the Institute of Biological, Environmental and Rural Sciences (IBERS), Aberystwyth University. He explains that IBERS high sugar perennial ryegrasses are more efficient converters of grass into milk and meat than alternative varieties and also reduce emissions of nitrous oxide, ammonia and methane by livestock.

“The best performing intermediate and late varieties on the current NIAB list are high-sugar types, allowing farmers to benefit from advances in breeding.”

Researchers are also focusing on the water efficiency of grasses and clover, crossing ryegrasses with more drought resistance grasses such as fescues to improve the water efficiency and persistency of varieties.

“We are working with more novel grass ecotypes, including North African fescue species, which are particularly drought resistant and heat tolerant,” says Dr Humphreys.

As well as improving water efficiency, many drought resistance varieties have extensive root systems that help improve the structure of soil through improved aeration. Increasing soil porosity also helps retain soil water thereby both preventing flooding following heavy rains and providing greater water availability during drier periods. Improved soil structure also helps to reduce compaction by both animals and machines. Dr Humprhreys believes that commercial variety testing of drought-resistance types is five years away, with national listing likely within the next 10 years.

Research into reducing the environmental footprint of grassland agriculture has recently been given a boost with the award of DEFRA funding for four LINK research projects. These will be co-financed by industry partners and will last five years.

Dr Humphreys is excited about the future for grass in the UK, predicting that it will be used as an environmental safeguard and to produce bioenergy as bioethanol as well as its traditional role as a livestock feed. As a perennial, grass also has a significant role to play in helping to sink carbon.

He says that growers can already make a difference by paying careful attention to the attributes of a variety. The high sugar IBERS varieties (eg AberMagic and AberStar) are easily identified by their Aber prefix.

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