Subsoiling key to higher oilseed rape yields for south-west Barometer farmer

Sunday night saw the finish of the first part of harvest for south-west Barometer farmer Peter Snell from Wimborne in Dorset.

Seventy hectares of oilseed rape, mostly Castille with a small area of Kalif, had yielded “the right side of 4t/ha”, Mr Snell said, which was “considerably better than last year when sclerotinia was a major issue”.

“The combine yield meter on the first two fields was showing over 5t/ha, and even though I think it reads high, maybe by as much 20%, from counting trailers I know it has yielded well.”

Those fields yielded slightly better than the rest of the rape, which was on heavier land. “Realistically, those fields have done between 3.5 and 4.5t/ha.”

The difference he put down to being able to subsoil the lighter land before drilling with a Horsch Pronto. “Subsoiling allows good rooting for the oilseed rape without moving the soil hugely and, therefore, not losing soil moisture.”

The heavier land had been too wet to sub-soil – 119mm of rain in July 2007 followed by another 69mm in August – so he ran through with a Massey Ferguson Aramix cultivator before drilling. “It created a good tilth, but not the loose soil structure I was aiming for.”

All fields received comprehensive inputs during the season, including four fungicide treatments after the sclerotinia problems the previous year, 280kg/ha of nitrogen (including autumn N), 15kg/ha magnesium and 100kg/ha SO3 (sulphite).

Farm-scale compost trials in Pearl winter barley were cut before the oilseed rape, Mr Snell says. “Preliminary results suggest a significant benefit from the compost when combined with typical bagged fertiliser recommendations over and above that of the artificial fertiliser alone. Reading University are still working through the results and there are still wheat trials to cut.”

So far progress had been excellent thanks to the warm, dry weather, he said. And he was pleased to miss thunderstorms on Monday night. “Our thatching straw is stooked and drying out in the fields so too much rain will not be welcome. The Widgeon straw has nearly dried through – it is cut green, which makes the straw stiffer and less brittle – and, ideally, will be baled and brought in towards the end of the week.”

But forecast showery weather could delay the process, he admitted. Given fair weather, however, he could be combining one or other of winter wheat or spring barley by the end of the week.