How suitable cover crops are the key to a shallow min-till system

Labour and work rates were the main reason that 10 years ago I moved from a conventional plough and one-pass establishment system to a shallow min-till system.

My soils are quite heavy, with a high clay content, and I felt they had become quite tight and it was taking more diesel, metal and time to create a suitable seedbed.

Initially I cultivated to 4-5” with a tine harrow, and as my soils adjusted I was able to cultivate to a shallower depth.

I now use a heavy trailed 4m disc and follow with a Väderstad Rapid drill and when planting wheat after beans I direct drill.

It works well for me but I have found that suitable cover crops prior to spring cropping are an essential part of the system, to preserve and enhance soil structure.

I tend to plant earlier in the autumn now to get a good establishment but this can bring challenges in terms of disease and virus control.

It’s a balancing act and there is nothing set in stone — the tine harrow, and the plough and one-pass, are still in the yard for certain situations but I find I am using them less often.

Crop rotation has also changed in recent years: I have moved away from continuous winter cereals.

Septoria control in winter wheat was becoming more costly and brome became an issue in continuous winter barley as I moved towards min-till.

Switching to spring barley allowed me to get on top of the brome situation, and the addition of non-cereal break crops to my rotation in the past two years has helped further with grass weed control.

There have also been other benefits of nitrogen savings, breaks in disease cycles and increased cereal yields.

I am settling on a target rotation now of spring beans, winter wheat, winter barley, winter oilseed rape, winter wheat, winter barley or spring barley, followed by a cover crop then back into spring beans.

I managed to get out onto ground recently (with duals on) to spray the oilseed rape with Astrokerb at a rate of 1.5 l/ha.

In the yard, I am modifying some shed space to give me more temporary gain storage capacity which will help with workload at harvest time.

I am also getting to grips with a new fertiliser spreader with weigh cells that has an improved headland management system.

Having managed to get most of the winter barley sprayed pre-emergence last autumn the pressure is off here.

There is one winter barley field that has received no weed control to date which will make for an interesting comparison at the Teagasc Crop Walk I am hosting on February 8 at 11am.​

Vincent Macken farms at Kentstown, Navan, Co Meath

Local advisor: Shane Kennedy, Teagasc, Drogheda