A few weeks ago, Quinns of Baltinglass completed a second year of field evaluation of soya beans in our unpredictable Irish climate. This was yet another stern test – last year, it was heat and dryness; this year it was wet and lateness.

One big question was answered – the crop did ripen for harvest and it did go through a combine. The theory was that the crop should be ready for combining around late September/early October but this did not happen. Harvest date was 22 October and marginal at that.

Earlier this year, I visited this crop, which was again sown to the variety Siverka, with David Shortall of Quinns. At that stage the crop looked to have considerably more potential than the previous year. There were pods formed right up to the top of the stems – these had all aborted last year – and the lower ones were not as close to the ground for combining. This year’s crop looked more bulky, but the question then was, would this carry higher yield potential?

In all such instances, the combine is the final arbiter. David was on hand again to explain that the crop had been sprayed off with diquat to help ripen the crop. They had used a strong rate but even after quite a number of days, the crop was still not fully dried down.

David Shortall of Quinns.

Harvest maturity

On the day of harvest, the crop was noticeably high in moisture. Most of the 15ac field looked ripe but there was a sizable patch where the crop was still quite green, with leaves still intact. Whether this was a result of high fertility helping the crop to hang on longer, or a possible deficiency delaying ripening, we had no idea, but it was noticeable.

While the bulk of the crop looked ripe, there were individual plants scattered throughout that were green and immature. This was not just that the leaves were still present – the seeds were much less mature too and these felt more like an apple than cheese when bitten.

David had tried a run of a different variety this year but this looked less impressive than the Siverka (see picture right). He has also experimented with seed density at planting and farm manager John Fallon had sown three different seed densities – 55, 60 and 65 plants/m2. The higher rates grew taller and denser but there was little sign of obvious benefit at harvest.

UK opinion

Following conversation with Soya UK, David told me that late-maturing plants can often be a consequence of variable seeding depth and uneven emergence. He said that the crop was very slow to emerge and this may have been a factor in the variability. The UK people said that 2019 was their latest harvest in the 15 years of growing soya there.

The second variety of soya beans was visibly earlier but yield did not impress. \ Philip Doyle

Seeds and seed fill

While the crop looked quite promising towards the end of flowering, questions had arisen by harvest. There were definitely fewer pods per whorl at the base of the plant but more further up on the plant. But it was also obvious that the number of seeds per pod was lower than last year and the seed size seemed smaller also.

Pods that had three good-sized beans last year had only two smaller beans this year. And the upper pods seldom had more than one modest sized seed present. So while we had better foliage production, the potential for yield did not impress at harvest. We wondered if the same conditions which seemed to turn off seed fill in faba beans might also have caused the soya to stop filling early?

That said, half a day took out the crop with minimal fuss and the straw chopped. There was some dragging at the blade as the soil was naturally loose.

Yield

Moisture levels were high on average at 27-28% but you can’t wait forever. The crop yielded 0.9t/ac at that moisture, which is just over 0.8 t/ac at 20% moisture. So not a bad yield for a challenging year.

David said that non-GM soya beans are currently trading between €375/t and €425/t at 14% moisture and so these are the price levels at which this crop must be valued. While costs are relatively low, the crop would still need protein aid to make it viable, even with slightly higher yield.

In summary

This time last year we concluded that the crop needed further evaluation. Now, a year later, we can draw the same conclusion. But yield was better and perhaps could be better again if we got a year closer to normal, whatever that is. But the promising field performance should move the crop closer to serious research consideration.