Gillian O’Sullivan: Innovative ways to deal with dry summers

This has been our Achilles’ heel since beginning farming, and a more frequent occurrence in the past few years.

It’s quite concerning to read the temperature and rainfall projections due to the effects of climate change on the Met Éireann website.

Over the next 25 years we should plan for “significant decreases in average annual precipitation most especially in the summer with a greater number of extended dry periods,” their report says.

Average annual temperatures are expected to increase by 1-1.6⁰C — that doesn’t look huge, but given that the average annual temperature range is quite tight this will be problematic for farmers, especially those with freer-draining soils.

The average temperature in Ireland is 9-10⁰C, and the vast majority of our weather is 5⁰C north or south of this.

So a 1-1.6⁰C increase is a big deal. It brings associated extreme warm weather events — which previously sat outside that band —closer to the norm.

The report also mentions a positive in the expected 35-40 additional days of growth at the shoulders of the year, but for me a few weeks of dry weather in the summer cancels out that quite quickly.

Over the years we have continually planned to offset the impacts of a dry spell with many measures.

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

We changed to multi-species pasture in the most drought-prone fields to take advantage of the tap roots. Because when it’s dry, the only things that remain green are the docks, bull thistles and ragwort, demonstrating clearly the advantage of a large root system.

Mentally it has been a challenge to reduce stocking rate on the milking platform from around 2.55 cows/ha to 2.3. It’s hard to equate being less productive with being more successful, but that is the way things are now.

We are always looking outside of out farm gate for inspiration, so how do other dairy farm systems cope with dry spells?

The high-input systems go indoors and feed, while some pasture-based operations look towards irrigation like in New Zealand.

Neither of these solutions are appealing; depending on irrigation is going out of the frying pan and into the fire when water usage is such a growing issue.

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

We generally view drought as being a lack of rain, so the solution is water, but recently I spoke to farmers with a different perspective. Interestingly their view is that the problem is not water but the ability of the soil to retain it.

Some farmers in the US and UK are targeting building the organic matter levels in their soils through crops, grassland management and livestock.

Not only is organic matter the sponge of the soil, but a 50pc of nitrogen comes from the soil organic matter pool.

We are almost brainwashed into thinking that every grain of fertiliser translates to providing plant-available nitrogen, but things are not that simple below the surface of the soil as both chemistry and biology dictate the outcome.

A farmer in the south of England told me he chanced a dramatic change in grassland management. Where his sandy soils couldn’t cope with the heat, growing less and less each summer, he opted to grow grass covers to 3,000kgDM and leave the cows in to graze it down to 1,500kgDM.

It sounds crazy and we all know the production effects of grazing heavy covers, but it resulted in him growing grass throughout the summer, significantly reducing his 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 innovators.

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