Breeding grass to withstand excess water

Ireland is (sometimes incorrectly) judged as having high rainfall – much as NZ’s West Coast. Ireland is like the West Coast in that the westerly winds bring rain and dump it in quantity on the ‘emerald isle’.

This year all Irish farmers have been hit by the rain: it has ruined tillage farmers’ crops, and sheep, beef and dairy farmers have also been hit, causing a drop in prices.

John Spink, the head of crop science at Ireland’s Teagasc Research Institute at Carlow, says Ireland’s high rainfall and climate change is causing the loss of a fair proportion of winter sown cereals due to waterlogging.

To try to mitigate this problem they are doing genetic research, seeking to create new species of crops and grasses with improved waterlogging resistance. They are trying to deal with wet and cold, Spink says.

“We are at the early stages of the research. We have done some screening in the glasshouse and we are starting this autumn in the field and will be irrigating during the winter. That will be to look at genetic material and see how much variation there is in available genetic material.

“Another strand is working with people at Maynooth University, near Dublin, who have been working on Arabidopsis; they have found pathways which bestow waterlogging tolerance. They are seeking the same thing in grasses.”

Spink says waterlogging has a similar outcome to drought because it has long term impacts. Waterlogging of ryegrass over the winter, while it won’t kill the plant, will limit the size of the grass canopy.

“That delays spring growth, so it’s not really about being able to graze over the winter but being able to get better shoulder growth in spring – more early season growth, which is very valuable grass obviously.”

Spink says Ireland seems to be experiencing more extremes of weather: in the past 30 years the mean weather data has shown an increase of 90mm of rainfall.

While Ireland doesn’t have some of the heavy clay soils found in NZ, it has another problem also much talked about – lack of sunshine.

“The water use of our crops in summer would only be about 3mm, compared to places such as NZ where you get 9mm. We require a lot less water for crop growth because we don’t have the high intensity of radiation or the winds you get that dry out the ground.”