Crop protection and plant care

Many farmers believe that giving up ploughing condemns their fields to heavy weed infestation. It is true that switching to a simplified tillage system requires updating the approach to crop protection and that, due to changes in the “distribution” of the soil seed bank, more weeds may appear during the transition period between ploughing and no till. However, both scientists and practitioners point out that an increase in weed pressure is not a rule, and if the problem does occur, it is not permanent and is relatively easy to manage.

Important! In simplified systems, keeping fields free of weeds, pests and diseases becomes a priority. The best results are achieved through prevention, combining mechanical and chemical methods, and caring for the field throughout the entire growing season.

Weed control without ploughing

Because soil is not inverted in no till farming, weed seeds and volunteer crops remain closer to the surface: in no till farming at a depth of about 15 cm, and in zero tillage at around 5 cm (for comparison: with ploughing it is about 20–25 cm). Is this always a problem? That depends on the requirements of specific weed species.

- Some weeds germinate quickly, but in dense stands they compete with each other and many seedlings die. Moreover, they can be easily removed using various treatments (more on this below).,
- Seeds located shallowly also become food for birds and rodents.

On the other hand, seeds placed deeper in the soil may either die (e.g. corncockle, rye brome, dandelion) or remain preserved for decades (e.g. wild oat, blackgrass, cornflower). As you can see, weeds have always been and will remain a challenge in every tillage system. The key is to adapt the weed control strategy to the chosen system.

Mechanical weed control

Mechanical methods mainly include shallow tillage and specialised tools such as weed harrows. Harrowing allows emerging weed seedlings to be destroyed by uprooting them or covering them with soil.

Rolmako offers a range of specialised tools for mechanical weed control:
- ActivAgro weed harrow,
- Matrix rotary hoe,
- SpringExpert mulch harrow,
- ComboTill cultivator and mulch harrow combination,,
- SpeedCutter ultra-shallow tillage harrow.

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This operation is usually carried out early, when weeds are at the so-called white thread stage (just before or just after emergence), to weaken them as much as possible before they start competing with the crop. Practical experience shows that mechanical weed control can be an effective alternative to chemicals – farmers testing weed harrows claim that under favourable conditions they can significantly reduce weed pressure in cereals without herbicides. Of course, effectiveness depends on weather and timing (a sunny, dry day is best so uprooted weeds dry out) and on the crop species (not all tolerate harrowing equally well).

In row crops (sugar beet, maize, potatoes), inter-row cultivation is an effective method. It is usually carried out when crop plants are large enough not to be buried by soil (e.g. maize at about 20–30 cm height).

Chemical weed control

Chemicals methods in no till farming often become indispensable, especially at the beginning of implementation. The first step in weed control is usually applying a non-selective total herbicide such as glyphosate to the stubble. Spraying shortly after harvest destroys emerging annual weeds and volunteer crops and weakens perennial weeds.

Important! The EU has authorised the use of glyphosate until 2033, but its use is subject to strict regulations.

It must be remembered that glyphosate only works on plants that have already germinated. Weeds emerging later, after sowing the main crop, may require treatment with selective herbicides.

The important protective role of mulch

Mulch made of crop residues is an important ally in weed control in simplified systems. Leaving stubble, straw or a cover crop on the field creates a natural barrier for new weeds – it shades the soil surface, making germination more difficult. The mulch layer works physically (covering the soil) and chemically – some decomposing residues release substances that inhibit seedling growth. Research shows that a sufficiently thick mulch layer can reduce weed emergence by several dozen percent compared to bare soil. Of course, mulch will not eliminate all weeds, but it will reduce their number and vigour.

Farmers can use this effect by sowing a stubble cover crop: a fast-growing cover (mustard, phacelia, buckwheat) suppresses weeds, and after winterkill or termination, residues cover the soil over winter. In spring, mulched fields warm up more slowly, but they retain more moisture and have fewer weeds than ploughed fields, where each furrow brings a new batch of seeds to the surface.
Important! Care should be taken to ensure that mulching material is not itself a source of weed seeds – straw chaff should come from clean fields, and manure should be well composted to destroy seeds in the digestive tract of animals.

Field monitoring and prevention of diseases and pests

More residues on the soil surface and higher moisture in mulch can favour certain stem base and root diseases. However, abandoning ploughing also means less disturbance of beneficial soil organisms, which can act as antagonists to pathogens.

Field monitoring (crop scouting) involves systematic observation of crops to detect the first symptoms of diseases or the presence of pests. It requires knowledge of symptoms and pests, but pays off with the possibility of rapid response. For example, controlling isolated aphid hotspots is easier than dealing with a mass infestation, and applying fungicides or preventive sprays after the first fungal spots appear on leaves can prevent the disease from spreading across the entire field.

Prevention of diseases and pests largely relies on crop rotation and proper agronomic practices (more on the benefits of crop rotation in e-books 1 and 3). When different crops are grown each year, pests do not constantly find their preferred host, and diseases have fewer opportunities to survive on residues, as the following crop is not a susceptible host.

Important! A well-designed crop rotation is the best way to avoid outbreaks of diseases and pests.

In addition, prevention includes:
- thorough management of crop residues from disease-susceptible crops (shredding and shallow incorporation),
- selection of resistant or tolerant varieties,
- seed treatment,
- field hygiene (weed control, removal of residues after vegetable and potato harvest).
Balanced fertilisation is also essential – a well-nourished but not over-fertilised crop (especially with nitrogen) is more resistant to pathogen attack. Excess nitrogen weakens plant tissues and may promote fungal diseases and lodging in cereals.