Farm Ireland

Saturday 24 March 2018

Fertiliser use now an exact science

Helen Harris

Helen Harris

This is a fabulous time of year, when everything seems to be bursting into life. It's lovely to see newborn lambs skipping around the fields and the daffodils starting to come into bloom.

We have been flat out taking soil samples for Teagasc. I think I know every back road and boreen in Co Kildare.

It will soon come to an end as the next fine day will have half the country out spreading slurry or fertiliser. You can't take samples after that as it would give a false reading.

When we started this a few years ago, it was mostly for REPS plans. Then they brought in the rule that all tillage farmers had to test for organic matter and now it's required for nitrates plans too.

The attitude of farmers has also changed over the last three years. Most initially thought it was an unnecessary expense, but now more and more are getting samples taken for their own benefit. Given the high cost of fertiliser in today's market, they realise they need to know exactly what they have to use to maximise each crop.

Teagasc figures for this year on the costs of growing crops illustrate this point perfectly. Just to buy and spread fertiliser is slightly under €200/ac. That means if you are growing 500ac of crops your fertiliser bill alone will be about €100,000. That's before you have bought sprays or anything else.

So the days of guessing are long gone.

The merchants are on the same wavelength, with many having accredited labs. If you give your local rep the sample, most will send it off and have the results back in a couple of weeks. But make sure the lab they use is accredited. There is not much point in going to the trouble of taking soil samples if the Department of Agriculture won't accept the results.

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After tackling the nitrates plan we worked out what we needed and now have 0:7:30 and Sulcan CCF (27.5pc N+6S) sitting in the shed.

We bought both of these in bulk as it works out cheaper than big bags. It also suits us in that we can utilise the empty grain sheds that are high enough for the arctic trucks to tip.

However, it does mean that there is a bit more running around as it is not as easy to transport.

Last year we bought ASN (26pcN+14S), but it looked like the sulphur did not spread evenly through the crop. It looked fine while spreading but you could see stripes in the fields as the crop developed. But it was the vigour of the plant as well as the colour. The outside plants that lacked sulphur were weaker, while the plants directly behind the spreader were much stronger.

The fertiliser spreader is serviced and ready to go, but the ground is still too wet to travel on. We are going to put out trays and check every compound is spreading correctly. We planned to do this last year too but it never happened. The next dry day with appropriate ground conditions will see Phil get the 0:7:30 out on the winter crops of wheat and barley. The first split of nitrogen for the winter barley will be going out, depending on the weather, at the beginning of March.

We would normally spread about 40 units in the first split and then come back about three weeks later with another 30 units. We've been paying a lot of attention to the growth stages of the crops because we've had such a mild winter.

After last year's hard winter the crops were at completely different stages of development.

I am slightly nervous that we may get another late cold spell this winter. There is no point in spreading fertiliser if the plant is not growing and cannot take up the nutrients.

We tested the ground temperature last week and even though the air temperature was about 10C, the ground was only 5.5C. The plant really doesn't start growing until the temperature reaches 12C, so if we do get a cold spell it could really set the plant back.

Helen and Phillip Harris are tillage farmers in Co Kildare. Email:

Indo Farming