WHILE minimum tillage might save time, ploughing for oilseed rape establishment is still the best option on many Scottish soils, argued Alistair Gordon.

He’s the regional technical manager in Scotland for agronomy firm, ProCam, and said the benefits of ploughing can be felt from establishment right through to harvest.

“Ploughing gives fewer crop failures and a more consistent yield,” explained Mr Gordon. “It reduces slug numbers and volunteer cereals in oilseed rape – our biggest challenge with oilseed rape is simply getting the crop up and away.

“Ploughing also opens up the soil so it is freer-draining and helps eliminate problems with sterile brome, which are increasing,” he argued.

Even with hybrid oilseed rape varieties which offer enhanced autumn vigour, it is still essential to create the best soil conditions for establishment, he added.

“Where you min till, you have to control slugs and control volunteer cereals in oilseed rape. Once you add in the cost of applying slug pellets and taking out volunteers, establishment costs for either method look remarkably similar.

“I can understand why people use min till on heavier soils in England – because if you plough heavy clay it can take a lot of power harrowing afterwards to get anything approaching a nice seedbed.

“But ours are mainly sandy soils and we can almost go straight in after the plough with a drill. Also, min till doesn’t work as well up here where soil conditions are wet – trying to put a subsoiler through it in a catchy, wet season just creates slots, leading to problems with slugs,” said Mr Gordon.

He added that min till is still practical in drier conditions and where there aren’t sterile brome problems and less crop residue, as well as on some heavier soils.

In other situations, he urged growers to plan crop rotations well in advance, to allow enough space to incorporate ploughing.

“People often use min till to save time because they are trying to get winter oilseed rape in after spring barley by the first week of September. That’s understandable, but ideally you want to be planning which fields are going into oilseed rape a year ahead.

“That way, you can prioritise those as the first fields to drill with spring barley, so you know they’ll be harvested first and give you maximum time to plough.

“If you can’t plough the whole field, at least consider ploughing an 8m band around the headland. This area needs loosening the most because it suffers more compaction with machinery turning.

“A key decision to take before ploughing, which has an impact on crop establishment, is whether to incorporate or bale the straw. People like the extra income from baled straw and if you bale it, the cultivation machinery doesn’t have to cope with trash, and less trash helps to reduce slugs,” he said.

“My preferred option would be plough every year and before every crop, and remove the straw if the weather allows.

“If slugs are a problem, they mostly come from the field boundary, but new metaldehyde stewardship scheme rules require a 10m exclusion boundary around the whole field.

“So, if slug pellets are needed, I’ll be using Ironmax Pro slug pellets, which is a ferric phosphate product,” he added.