With many more hectares of cover crop about in the winter of 2018/19 many farmers are having to cope for the first time in a generation with having a crop in a field at this time of year.

With over 40,000ha planted with the support of either GLAS or the fodder production incentive, there are over 100,000 acres that need to be cleared before the next crop can be planted.

That which was sown under the fodder incentive scheme should be grazed or have the fodder harvested for livestock and one might argue that, given the current dry soil conditions, grazing is one of the best ways to clear this vegetation.

But I might add here that part grazing and part incorporation is likely to be the best alternative as it returns both organic matter and available nutrients to the soil for the next crop.

The thing that must be avoided on worn tillage ground is grazing a crop to the butt and especially in wet conditions.

This can result in even more damage to your soil in the long term.

Desiccation not the default

For those who have crops in the field today and are wondering what to do the answer deserves a little consideration.

The default method of destruction appears to be Roundup.

This is what farmers are thinking about as their first option and it will work. But is this merely helping the anti-lobby as it may not sit comfortably with consumers?

One important thing to remember is that one of the objectives of the continued planting of catch/cover crops should be to have your soil in good enough condition to plant without ploughing.

When the general structure of your soil has improved and when you have roots growing over winter to cultivate the seedbed/root zone, then one should avail of the option to plant without ploughing.

That said, most fields are not in this position because many growers are only growing catch crops for a few years at most while many others have them for the first time this year.

This should be a factor in deciding how best to destroy a catch crop and prepare your field for the next cash crop.

The options should be most influenced by the bulk of vegetation present and the previous husbandry of the land.

How much bulk

The first decision must be based around the bulk of vegetation in your crop.

Where the bulk is small, either because it did not grow well or because some of the species have already been killed by frost, one can consider establishment either by ploughing or by just cultivation, or even no-till.

The next question then revolves around previous husbandry. If your field has been getting some form of organic matter on a somewhat regular basis (every second year or more) it should be in a better position to cope with the incorporation of the organic matter growing in your crop today.

That means crop incorporation in a green vegetative state should be an option whereby you can plant without having to plough and expect a significant nutrient contribution from both current and historically incorporated organic matter.

However, if this is the first time a catch crop or green manure or any other form of organic matter was used in this field, you may have fewer options.

This is especially the case where the soil is tight and difficult to manage.

In this type of scenario one could consider discing to knock down or kill the crop with the intention of ploughing to establish the next crop. Of course, one might also consider spraying directly, well ahead of ploughing.

Where a crop is quite bulky, either because it was sown early or it gave tremendous growth or a combination of both, then incorporation without ploughing will be more challenging.

Again, this may prove more feasible where organic matter of some sort was used frequently in the past as it should have the biology needed for a quick breakdown.

But you still need to have a naturally friable soil to establish successfully without inversion.

Incorporating a big bulk of green vegetation could prove challenging for many farmers and if you can’t do it successfully regrowth is likely, leaving you with additional work and cost.

So where a big bulk of material is present, if it is not to be grazed then burning off with glyphosate may be the most straightforward method.

The lighter crops

Lighter crops of foliage do provide more options. Many of these can be easily incorporated either by cultivation or ploughing or a combination of both.

The same rules apply – if soil is not in good condition already, ploughing may be your safer bet for spring planting.

But you can still kill these quite easily by discing not far ahead of ploughing or planting.

Incorporation is preferable if you have time and a decent tool for it. But desiccation is a real option also.

Other methods of crop destruction

Depending on how the weather develops, a number of other methods of crop destruction could be considered.

The first is that used by Philip Reck a few years ago when he rolled his catch crops during heavy frost.

It is possible that it will be more successful on fleshy-type vegetation as it may be more difficult to kill a cereal with this method

The result was that all of the species present in that mixture were damaged and subsequently destroyed by the frost.

While one cannot guarantee either the frost or the kill, this could be worth considering.

It is possible that it will be more successful on fleshy-type vegetation as it may be more difficult to kill a cereal with this method.

Another option is one commonly used in other countries and generally ahead of the plough.

This uses a specially adapted roller fitted with vertical blades to both roll and cut the existing foliage (see picture).

This is commonly used to chop up taller species such as phacelia or vetch.

If a crop is rolled in this way, the cut material should die relatively quickly leaving a relatively short stubble to either disc up or plough down.

As with all other practices relating to catch crop inclusion, the options increase as the practice is repeated over time.

Dead or alive

Is incorporation of a living fresh crop better or worse than incorporating a dead one? This has long been a real question for the destruction of catch crops. Will more good happen either faster or slower from either approach?

There are no clear answers to this question but one must suppose that living material is likely to decay faster than dead material and that this is more likely to release nutrients quicker.

But then the longer it takes for this material to decay completely, the greater the chance that it can do more for the soil biological system. This of course may not be correct.

It is reasonable to suggest there is less potential for any negative fertility consequences when soft living material is incorporated as distinct from very ligneous material like straw.

This would pull on nitrogen availability in the early years of incorporation. But a few incorporated catch crops might be a good way to start a process which would add more carbon to a soil in the long term