Farmers must keep in mind their crop rotation when sowing crops this spring.

That was the message from Teagasc research officer Dermot Forristal at the Teagasc National Tillage Conference.

With many winter crops not sown, farmers may have no choice but to plant a different crop to what had been planned. This makes it more difficult to stick to a crop rotation structure.

Where the intended crop may not be planted, it is important to try to keep an entry open for the next crop that is planned for 2025. Dermot outlined ways that this can be done.

Options

Where winter wheat or winter barley were to be sown, spring wheat or spring barley can be planted in their place to keep the rotation in order. Similarly, spring oats can be planted where winter oats was planned to be.

Where winter oilseed rape was not planted, growers should aim to plant spring oilseed rape or spring beans where the rotation allows.

Teagasc trials have shown the value of crop rotation, with an 11% to 19% increase in yield, improved weed control, increased nutrient efficiency and a less condensed workload for man and machine at planting, fertiliser and spraying timings, as well as at harvest.

Analysis has shown that at average yields and 2024 prices, a winter wheat crop after a break crop will deliver a 15% higher yield and an 82% higher margin over a continuous winter wheat.

A five-year rotation including two break crops will also deliver an average of €203/ha/year more than continuous spring barley.

For example, while winter oilseed rape is expected to have a lower profit than spring barley, when the benefits on the following crops is taken into consideration, it will leave a greater margin for a farmer over the course of the rotation. Farmers should take this into account when deciding on what crops to grow.

Proportion

The proportion of break crops in a rotation also has an impact on the profit margin over the length of the rotation.

While a continuous wheat and barley rotation will leave an average margin of just under €400/ha/year, including one non-cereal break crop every five years brings this up to €470/ha/year.

Planting continuous cereals with oats as a break crop every third year will improve this further to €570/ha/year, while two break crops every five years leaves the highest profit at €620/ha/year over the course of the rotation.

Dermot reminded farmers that while break crops have been shown to improve profitability, this can only be done where there is a market available for the crop.

So while planting a certain crop this year may leave the highest margin, this may have lasting consequences on the crop rotation and the margin of subsequent crops.

Farmers should consider the costs and value of every crop across the length of their rotation rather than for one individual year.