Turning the soil in preparation for planting the crop is as old as farming itself, yet even after many thousands of years, the practice is still being developed and refined, as evidenced at Agritechnica 2023.
For much of that time, ploughing and harrowing was undertaken by draught animals. Last century, suddenly gave way to machinery – enabling the plough to dig ever deeper, an aspect of the craft which is now being reconsidered.
Rethinking establishment
The accepted notion that inverting the soil to a depth of several inches before pulverising it into a tilth being the best way to establish seedlings is being challenged as never before, and implement manufacturers are responding to this trend.
As reported in Agriland.ie, there has been a movement by the big players to invest in smaller companies that are already specialising in surface disturbance, rather than deep tillage; and the fruits of these unions were on show at Agritechnica 2023
The concept of treating the soil as a biological ecosystem to be nurtured, rather than a simple growing medium to be beaten into submission is gaining traction within farming, helped by the EU’s target of having 25% of the land farmed organically by 2030.
Soil first at Agritechnica
Companies that are already taking this approach were well-represented at Agritechnica, and they all seek to disturb just the surface in some way, whether it be to produce a top tilth, disrupt weed seedlings or incorporate a cover crop.
The reasoning behind leaving the subsoil alone lies in the realisation that soil structure is dependent on the microbes within it, and it is chiefly fungi which are responsible for creating a crumb like texture.
Disruption of the fungal mycelium will reduce many soil properties which we deem desirable, and the organic movement has, over the last few decades, completely reversed its position on the role of ploughing in organic farming.
Surface care
The German company Treffler, is one company that has been leading the way in light cultivations, and claims to have invented the precision tine harrow.
Both the machine and the principle have been copied elsewhere, for it epitomises the soft approach to regenerative farming, which shuns heavy machinery being drawn over the land by thirsty tractors, plenty of which also featured at Agritechnica.
Another item often seen being used in this new wave of cultivators, is the sun or finger wheel in various forms. When mounted at 90° angle to the ground, they are used to either break a surface crust, or take young weed seedlings out of an established crop.
Set at a 45° angle to the ground, they disturb the soil around the base of the growing crop plants, disrupting any weeds that may be competing for the nutrients and moisture.
In this format they are often deployed in conjunction with interrow hoes and broad winged tines, which keep the ground clear of weeds between the rows.
So far, to remove the weeds within the rows the use of row recognition, or RTK satellite navigation, is required to precisely locate the crop plant and hoe around it. This adds a large expense to the process.
It is this combination of digital technology and the revision of cultivation techniques that is fuelling the promise of herbicide free crops entering the mainstream of agricultural practice.
Kverneland, for instance, appears to be working on the principle of having the implement navigation system as a separate unit to which various cultivation implements can be attached, although at present it is only being shown with the Onyx interrow cultivator.
Keep it covered
Weed control, however, is not the whole story. Another tenant of organic, or regenerative farming is that the soil should never be left bare, there always needs to be a crop growing on it.
There are many reasons for this, but the overall view is that soil heath is supported by the interaction between plant roots and the soil biosphere. Retention of moisture and nutrients are two further advantages.
Piggybacking an air seeder unit on to a shallow cultivator, be it disc or tine, is the method favoured by most manufacturers when it comes to seeding a field with a cover crop.
To what extent the stubble is incorporated will depend upon the depth of cultivation, yet there is a train of thought within the organic movement which believes that surface litter is a bonus for the worm population, and once that is well established then the stubble is quickly dealt with without the need to bury it to any great depth.
Managing the cover crop
Having done its job the catch crop will need to be killed off and incorporated back into the soil, and, once again, it is argued by organic farmers that once dead, it is the job of a healthy and diverse soil biosystem to incorporate the residue rather than rely on intervention with heavy cultivators.
Slicing the cover crop roots just below the soil surface would be the accepted method of doing this, and there were plenty of implements on show which achieved just such an effect, with mixing it in with the top soil being a natural side effect.
Treffler has another approach to the task and that is its cutting roller which knocks down the crop and slices, while on the ground with three elements.
The first closed roller turns over the plants or stubble in the travel direction. The two rollers that follow cut at a right angle to the travel direction. Theses two rollers are connected by a chain ensuring that the knives of both rollers are always offset to one another.
Agritechnica shows the way
Shifting to regenerative farming practices or converting to organic is often said to principally involve a change of mindset, everything else follows from that.
Looking at the light cultivation implements brought to Agritechnica by the major manufacturers, it is clear that they are anticipating this move and have a range of tools ready to hand that will meet the new requirements of growers.
However, getting the best use of them will require taking on board a whole new knowledge of the soil and its management. The tools are there, but the expertise needed to use them efficiently may take time to accumulate.