Irish farmers should be somewhat wary when purchasing soil inoculants and that a more effective way to increase productivity is to ensure diversity of plant species in the grass sward, Dr David Wall of Teagasc has said.

Applying microbial inoculants, such as soil enhancers or seed dressings, to Irish soils may not be as effective in terms of improving yields on grasslands as they are in Mediterranean countries, he said.

“Before you purchase, ask for proof of efficacy in our environment – a high-carbon environment.

“Our soils are carbon-rich and have tonnes of soil organic matter. What happens when these products are applied, is the local population of biology in the soil kick the non-native microbiology around the place,” Dr Wall said.

He added that Teagasc is open to innovation and open to products that can stimulate growth however the context in which they’re being tested in is important.

“We’re moving towards a low chemical future and if the nutrient tap is turned off in the morning – in order not to have reliance on bought-in feed we will need to increase sward diversity,” he said.

The mindset that herbs “don’t last” in grass swards must change and must not be seen as a failure, he maintained.

Increasing sward diversification plays a larger role in increasing grass yields than application of microbial inoculants.

“It’s important not to put all your eggs in the one basket when it comes to grasslands. A ryegrass-only sward is not going to produce as much as a ryegrass plus a red or white clover, plus chicory and plantain,” he said.