Gillian O’Sullivan: Innovative ways to tackle dry summers

Summer grass growth is a fickle mistress in our part of the country. We break the waves of growth from behind the rain but are very hard to find with some dry days.

The southeast was tracking rainfall about 20 percent below the long-term average in late May, and seeing how things go in June, the difference will be greater.

This has been our Achilles heel since we started farming, and is a more frequent occurrence over the years.

It is worrying enough to read the temperature and precipitation projections on the Met Irene website due to the effects of climate change.

Their report states that over the next 25 years we should plan for a “significant reduction in mean annual rainfall, especially with greater dry periods in summer.”

The mean annual temperature is expected to rise to 1-1.6⁰C – this does not appear to be very large, but given that the mean annual temperature range is quite tight, this would be problematic for farmers, especially those seeking free water. There are draining soils.

The average temperature in Ireland is 9-10⁰C, and most of our weather is 5⁰C to the north or south of it.

So an increase of 1-1.6⁰C is a big deal. This brings the associated extreme hot weather events – which previously sat outside that band – closer to ideal.

The report mentions a positive in the expected 35-40 extra days of growth on the shoulders of the year, but for me the few weeks of dry weather in the summer cancel out very quickly.

Over the years we have continuously planned to overcome the impact of drought with several measures.

We usually keep a bank of fodder on hand such as bald silage, as we quickly learned that looking for fodder when it runs dry is like trying to find two tickets to All-Ireland on match day .

We turned to multi-species pasture in the most drought prone areas to take advantage of tap roots. Because when it dries out, only dock, bull thistle and ragwort remain green, clearly demonstrating the advantage of a large root system.

It has been a challenge to bring down the stocking rate from about 2.55 cows/ha to 2.3 on the mental milking platform. It’s hard to compare being less productive with being more successful, but that’s how things are now.

We’re always looking outside the farm gate for inspiration, so how do other dairy farm systems deal with the dry spell?

High-input systems move and feed indoors, while some pasture-based operations look to irrigation as in New Zealand.

None of these solutions are attractive; Water use is a growing issue when going out of the frying pan and into the fire at the base of irrigation.

We are often told that to find the best solution, you must look at the problem from every angle.

We usually think of drought as a lack of rain, so the solution is water, but recently I spoke to farmers from a different perspective. Interestingly, his view is that the problem is not water but the soil’s ability to retain it.

Some farmers in the US and UK are aiming to build up levels of organic matter in their soils through crops, grassland management and livestock.

Organic matter is not only a soil sponge, but 50 percent of the nitrogen comes from the soil’s organic matter pool.

We’re almost bogged down in the thought that every grain of fertilizer translates to providing plant-available nitrogen, but beneath the soil’s surface things are not so simple because both chemistry and biology determine the results.

A farmer in the south of England told me that he had experienced a dramatic change in grassland management. Where their sandy soils could not withstand the heat, becoming less and less every summer, they opted to increase the grass cover to 3,000 kgdm and left the cows to graze up to 1,500 kgdm.

It sounds crazy and we all know the production effects of grazing heavy cover, but it results in grass growing throughout the summer, significantly reducing their feed bill.

As every farm is different, finding tailor-made solutions for your own farm is both a motivator and a challenge. As always, farmers are the greatest of the innovators.

Gillian O’Sullivan farms Dungarvan near Waterford with her husband Neil