Primary tillage – to invert or not to invert? That is the question

After stubble cultivation comes primary tillage, whose purpose is to prepare the soil for sowing. In the traditional system, this involves ploughing (most often in autumn), which inverts the soil, buries crop residues and loosens the soil profile. Today, however, more and more farmers are abandoning ploughing in favour of no till farming or reduced tillage, loosening the soil without inversion and often combining this operation with organic or mineral fertilisation.

Plough-based tillage – pros and cons

Traditional ploughing has long been considered an effective way of preparing land, but it has both advantages and serious disadvantages.

With the industrialisation of agriculture and climate change, the disadvantages of ploughing have increasingly overshadowed its benefits. Side effects are becoming more evident: degradation of soil structure, decline in humus content, faster soil drying and intensifying erosion. That is why many farmers today choose to reasonably limit soil-inverting operations and adopt reduced tillage or no till farming technologies.

Nevertheless, it cannot be denied (and the Rolmako brand does not deny it) that ploughing has been used for generations because of its advantages, listed below. It is worth knowing them and using them consciously.

Advantages of ploughing

The main advantages of ploughing include:
- Strong loosening and aeration of the soil in the topsoil layer. - Thorough burial of crop residues, weeds and seeds – everything is inverted beneath the surface. As a result, the field after ploughing is clean, free of weeds and old straw, which facilitates further tillage and sowing. Ploughing also buries weed seeds and volunteer crops deeply enough that many of them do not emerge, reducing weed pressure and allowing lower herbicide inputs in the following season.
- Incorporation of mineral fertilisers and manure into the soil – during ploughing, spread fertilisers or manure can be deeply mixed into the soil so that nutrients reach the future root zone.
- Reduction of diseases and pests – deeply buried straw or plant residues affected by diseases decompose faster in the soil, limiting the development of fungal pathogens and pests overwintering in residues. For this reason, ploughing is sometimes recommended for controlling pests such as white grubs, as it disrupts their habitat.
- A clean, level field surface – inverted soil leaves an even, residue-free surface. This makes finishing operations (harrowing, cultivating) and precise sowing at uniform depth easier.

Disadvantages of ploughing

Unfortunately, ploughing also has numerous drawbacks:br> High cost and energy demand – ploughing is a heavy operation requiring high tractor power and fuel consumption, and it is labour-intensive (low hectares per hour). The same area requires more time and fuel than with reduced tillage.
-Disturbance of soil structure and soil life – deep inversion disrupts natural soil layers and biological activity. Microorganisms and earthworms are moved deeper or to the surface, where conditions are unfavourable. Intensive aeration accelerates the decomposition of organic matter and the release of CO₂. Long-term plough-based systems deplete soil organic matter and beneficial soil organisms.
- Risk of plough pan formation – repeated ploughing at the same depth creates a compacted layer just below the ploughshare. This “plough pan” restricts root growth and water infiltration, reducing soil structure quality and water-holding capacity.
- Low bearing capacity and susceptibility to compaction – freshly ploughed soil is loose, which on the one hand facilitates sowing, but on the other significantly reduces its load-bearing capacity. Heavy tractors or seed drills can easily sink into it, leading to the formation of ruts. Moreover, intensively aerated and inverted soil dries out faster and becomes more vulnerable to wind and water erosion. Heavy rainfall on freshly ploughed fields can wash out fine particles and cause surface crusting after drying. Wind, in turn, blows away dry, loose soil – arable fields lose valuable soil particles and humus (we often see clouds of dust rising from dry, freshly ploughed fields).

Important! Traditional ploughing offers short-term benefits (soil loosening, a clean field), but it also comes with serious environmental and economic drawbacks. Despite this, it still dominates many farms. Farmers value ploughing for its predictability – inverted soil “forgives” mistakes (such as unevenly spread straw or weeds), because everything is buried underneath.

What is no till farming?

In general terms, no till farming means abandoning soil inversion with a plough in favour of loosening and mixing only the upper soil layer, while leaving part of the crop residues on the surface. Most often, this is done using stubble cultivators or disc harrows mentioned in the previous chapter (optionally subsoilers – for deep loosening without inversion, e.g. to eliminate compaction layers and plough pans). These machines operate at shallower depths (usually up to approx. 20 cm) and do not invert the entire furrow.

In practice, reduced tillage systems can take various forms: from very shallow cultivation at minimal depth, through strip tillage (strip-till, working only narrow strips under future crop rows), to complete abandonment of tillage (no till, direct drilling into mulch), where the soil is not disturbed at all before sowing (still rarely practiced in Poland).

Important! All these methods aim to minimise mechanical soil disturbance in order to preserve soil health and reduce costs – both purely economic and environmental/climate-related.

Advantages of no till farming

The main advantages of no till farming include both economic and agronomic benefits.
- Reducing the number of field passes saves time and fuel and lowers machinery wear. A field cultivated with a single implement in fewer passes (or directly with a combined tillage-and-seeding unit) can reduce cultivation costs by several dozen percent. Farmers also observe less soil compaction – fewer passes mean fewer ruts and less soil compression throughout the season.

- Soil structure and fertility improve. Less intensive disturbance promotes the rebuilding of crumb structure and soil porosity. Earthworms, fungi and other soil organisms are not destroyed every year by ploughing, so their activity naturally loosens the soil and increases nutrient availability.

- Soil erosion is reduced and the soil’s water-holding capacity increases. Crop residues left on the surface form a protective layer – mulch. This cover reduces water evaporation, protects the soil surface from sun, wind and heavy rainfall, and provides food for microorganisms. This is especially important given increasingly frequent drought periods interrupted by intense downpours – no till soils retain water better during dry years and are less prone to runoff during torrential rain.

Disadvantages – or rather challenges – of no till farming

Of course, no system is perfect, so the drawbacks of no till farming must also be mentioned.

- After abandoning the plough, weed pressure usually increases – weed seeds remain closer to the surface and more of them germinate. This makes better weed control planning necessary (more frequent use of post-emergence herbicides, as mechanical control options are limited). Pressure from certain field pests (e.g. slugs or white grubs) feeding in mulch may also increase, as well as the incidence of some diseases. Therefore, in no till systems, proper crop rotation, healthy treated seed and regular field monitoring are of great importance.

- Transition costs are another challenge – it is often necessary to invest in new machinery (e.g. cultivators and specialised seed drills) and learn new techniques.

The first years without ploughing can be difficult. Full benefits appear only after some time – the soil needs to rebuild its structure, biological life must increase, and the farmer needs to fine-tune agronomic practices under the new conditions. However, the experience of many farms shows that it is worth it – after a few years, yields stabilise and the soil becomes clearly healthier and more water-retentive. It is no surprise that the area under no till farming is increasing year by year, and the concept of reduced-plough agriculture is becoming increasingly popular.

More about how to cope with the challenges of no till farming can be throughout e-book 3:found “Without the plough, but with yields.”.

How to select the main crop production technology?

Every farm is different, which is why tillage technology should be selected individually. Soil type and field topography (erosion risk), climate and rainfall availability, as well as available machinery and operator skills must all be taken into account. When implementing new methods, experienced farmers or advisers can provide valuable support – it is worth learning from others and observing demonstration fields run by Agricultural Advisory Centres to avoid basic mistakes.