When the plough might be better

Minimum or conservation tillage has many benefits over ploughing, but flexibility and matching establishment method to specific soil conditions is crucial.

That was one of the main messages to growers and advisers at a recent Soil Management Initiative open day in association with Farmers Weekly at the Allerton Trust’s 310ha (766-acre) farm at Loddington in Leicestershire.

About seven years ago the farm started switching from ploughing to minimum tillage, but escalating grassweed control costs and a need to get crops established on heavy land in wet weather means farm manager Phil Jarvis is reverting back to the plough.

“We saw chemical costs increase from £18/ha in 1999, when we ploughed about 87% of the land, to £67/ha in 2004, when 27% was ploughed.

Non-inversion tillage also requires relatively dry soils and after tricky conditions last August, we decided to plough more of the land.”

About half was now ploughed, and the rest was under minimum tillage, with average cultivation costs of about £92/ha this year, compared with £111/ha in 1999 when the bulk of the land was ploughed, he said.

“There is definitely a case for keeping the plough because sometimes these situations are forced on you because of the weather.”

He acknowledged that for many smaller-scale growers, having the “luxury” of owning different types of cultivation equipment may not be possible, although he said there were other options, such as sharing with neighbours or using contractors.

Worcestershire farmer and min-till enthusiast Jim Bullock is now in the 10th year of minimum tillage on his 320ha (791-acre) farm near Malvern, but agreed that the plough still had a role to play, especially on heavier land.

After failing to get a good cover crop last winter, the plough was used to establish spring beans this year.

“The reason why min-till or direct drilling doesn’t work isn’t usually a machinery problem, it has more to do with the soil – if the soil conditions are right, it will work well.

You need vertical structure (fissures), not horizontal (eg, plough pans, compaction).”

Oilseed rape and spring beans could suffer particularly badly if the soil structure was poor, so growers needed to get a spade out to see what was going on under the surface before cultivating, he urged.

He was keen to reduce establishment costs further and was looking to use more direct drilling next season.

“Direct drilling has reduced fuel consumption (compared with the plough-based system) by 65% from 100 litres/ha to 35 litres and it only takes about one hour per hectare to establish a crop.”

Grassweed problems could be a bigger problem under direct drilling or minimum tillage, so the use of stale seed-beds and “balanced rotations” was very important, he added.

Badly spread or chopped straw residues could also cause problems with uneven soil moisture and slugs, so a heavy harrow was used following the combine to counter potential problems.