91% of drystock farms have insufficient soil fertility levels

A worrying trend has emerged, which suggests that the soils on drystock farms have inadequate fertility levels to grow grass.

Speaking at last night’s Teagasc National Sheep Conference, Teagasc’s Dr. Philip Creighton said that just 9% of Irish drystock farms had optimum levels of soil fertility in 2016.

Touching on the importance of grass to over 200 sheep farmers in attendance, the grassland systems researcher said: “We can provide practically all of the feed requirements (90-95% of annual energy requirements) of sheep from grass – be that grazed grass or conserved silage or hay.

It’s a high-quality feed with crude protein levels of 18-19% and high energy of 0.85-0.95 UFL. From a profitability point of view, every extra tonne of grass we utilise per hectare gives us an extra €105/ha in extra profit for the farm.

“If we look at the costs of feeding other feeds – grass silage for example – it’s going to cost us twice as much as grazed grass on a per kilogram of dry matter basis. And to feed concentrates, that’s going to cost us four or five times the cost of grazed grass.

“The key to the system is to have sheep grazing high-quality grass to achieve high levels of performance and high levels of output, which we ultimately want to turn into high levels of profitability at farm level.”

Creighton also outlined that the average sheep farmer utilises 5.6t/ha of grass each year and the target is to pull that up to 10t/ha.

To achieve this level of performance, he said, farmers need to focus on a number of areas, including: soil fertility; grazing infrastructure; grazing management; measurement; and reseeding.


Soil fertility

Continuing, he said: “Soil fertility is the foundation stone. If we don’t have productive soils, we’re not going to have productive grassland. We need to target a pH of 6.2-6.3 and soil indices of 3 for phosphorous (P) and potassium (K).”

Touching on the state of soil fertility on Irish drystock farms, he said: “There’s only 32% of drystock farms in the country within the optimum range for pH.

It’s a similar story for P and only 36% of soils are at index 3 or above, while 42% of soils are index 3 or above for K.

When these figures are combined – to look at the number of farms where soil fertility is at the optimum for these three parameters – just 9% of drystock farms have adequate soil fertility levels for grass growth.

Percentage of drystock farms at optimum levels of soil fertility to grow grass in 2016. Table source: Teagasc

To address soil fertility issues, he said: “The important thing to remember is that lime and pH levels should be targeted first.

You can spread as much nitrogen (N), P or K as you like; but if the pH of the soil isn’t right, those nutrients aren’t going to be used.

“20% of our annual variable costs are being spent on fertiliser and we need to make sure that we are spreading the right products in the right places to get value for money,” he said.

Steps to addressing a soil fertility issue:
  1. Test the soil and act on the results;
  2. Correct the pH first;
  3. Once pH has been corrected, focus on improving P and K indices.

Once soil fertility issues have been addressed, he said, farmers should then focus on grazing infrastructure, a grazing management plan, measuring and reseeding.