Leave the plough in the shed and reduce your seed rate if you want to make more money from oilseed rape. That was the main message coming from John Spink, head of crops research with Teagasc, at the recent Teagasc Tillage Seminar in Co. Kildare.
According to the Teagasc eProfit Monitor results from 2016, Spink stated, there was very little difference in the cost of growing the crop on the top 33% and the average cohort of farms. The main difference between the two crops was crop yield.
A trial carried out on establishment – across three sites by Teagasc – showed that there was no significant difference in the yield between different establishment systems.
In the trial, three crop establishment systems were used – ploughing, min-till and sub-soil systems. While there was no difference in yield, there was a big difference in the costs between the systems.
Spink estimated contractor costs for using a plough-based establishment system at €192/ha and at €110/ha for the reduced-tillage systems.
You can make significant savings on establishment costs and have no significant effect on yield.
Results of seed rate trials in Teagasc have shown that there is no significant difference in the yield of the crop; whether you plant 10, 15, 30, or 60 seeds/m². However, there is a big difference in the costs between these rates.
“There was a difference in one site and that was a very heavily pigeon-grazed site. If you looked at the crop in February, you would think there was no crop in the field at all,” he explained.
“In that case, there was a response to seed rate. Where there were more plants/m², the crop recovered better.
“As long as you can manage the pigeons and get a reasonably even crop established, there are potential savings to be made from reducing the seed rate.
10 seeds/m² costs approximately €10/ha and 60 seeds/m² costs approximately €60/ha.
Spink stated that seed rates have come down significantly over the years and yield has not been affected.
“Going back over the years, the standard seed rate was 120 seeds/m² or 6kg/ha and when it was lowered to 0.5kg/ha, it had no effect on yield.”
Spink made the point, that while reducing seed rate can save money, it is important to ensure you have enough seeds planted in case of poor crop establishment or slug and pigeon attacks on the crop.
That’s not to say that I would set out to grow a crop at 10 seeds/m². The risk is too high.
“In practical terms, aiming to put 30 seeds/m² in to get 20-30 plants/m² still gives you a degree of security. If you lose more than you expect, it’s not going to impact the yield of your crop,” he concluded.