How mulching works in agriculture ?

The mulching technique is highly recommended for anyone practising SCA (Soil Conservation Agriculture) and SCT (Simplified Cultivation Techniques). It is also universally applicable to virtually all crops (weeds, cereals, etc.).

The word mulching clearly sums up how this process works, which is to cover the soil with crop residues. But let’s go into more detail and find out how mulching works when applied to agriculture.

How does mulching work ?

The main advantage of mulching is that it initiates the breakdown of crop residues and Intermediate Nitrate Trapping Crops in place, making them easier to assimilate by soil life. It helps to fight against erosion, maintain biodiversity and fertility, and sequester large quantities of carbon.

Mulching can be an alternative to planting a cover crop, especially after a late crop such as maize. The latter does not provide a sufficiently developed plant cover before the onset of winter.

How to mulch?

Let’s take the example of mulching after a maize crop. After harvesting, the maize stalks are finely broken up using suitable equipment such as a shredder. They are then incorporated into the soil using a disc or star tool (such as Stell’Air).

Quality mulching is characterised by 2/3 residue/vegetation and 1/3 soil in the first 5 cm of soil. The aim of this shallow cultivation is to keep the debris in an aerobic environment. In fact, carbon tissues (lignin) only break down in the presence of air. As winter sets in and temperatures fall, decomposition slows down. It is therefore advisable to mulch quickly after harvesting.

Good mulching involves working the entire horizon. Many disc tools are used for this technique. However, if the spacing between them is too great, you have to work deeper to optimise the mixture. As a result, the horizon is worked to a depth of more than the recommended 5cm, placing the residues in an anaerobic environment. As a result, the mineralisation of the residues is greatly reduced.

The benefits of mulching for your crops

Mulching is a good way of caring for your soil effectively while improving the yield of your future crops. Discover the benefits that mulching can bring you on a daily basis.

Develops organic life and fertilises the soil

A mulch helps the development of micro and macro-organisms in the soil, which play a major role in the decomposition of residues. Their action transforms the mulch into organic matter. Some of this organic matter is mineralised, while some is stored and made available for the next crop.

Mulching therefore has a major impact on soil fertility and the quality of the crop grown afterwards.

Protects the arable layer

Choosing to mulch your soil is an interesting agronomic option for protecting it. Mulch protects it from erosion and the climatic hazards that would damage a surface left bare. Rain can cause the soil to settle and form a battance crust, making it impervious to any exchange. Mulching is therefore an ally in maintaining soil structure.

THE ACTISOL ADVICE : Mulching should be carried out using lighter equipment. When mulching is carried out at the start of winter with heavy equipment and an unsuitable roller, the surface horizon is compacted. This has the effect of severely limiting the action of air on soil degradation and macrofauna. One of the keys to good mulching is to ensure that the soil is as ‘blown’ as possible and not re-consolidated. A roller should not be used in soils with a high clay content. Combs are more suitable.

Stell’Air stars are ideal for this technique. Working by ripping and then spraying provides the perfect densimetric sorting for soil “winterisation”. Their spacing is the tightest on the market, so you can mulch the entire horizon from 0 to 5cm while leaving it blown.

Retains soil moisture

The mulch layer preserves the moisture in the soil by preventing evaporation. It also helps to maintain a cool temperature by protecting the soil from the sun’s rays. This soil cover allows rainwater to penetrate deeper layers more quickly, with the help of macrofauna that increase macroporosity at the surface.

Prevents weeds from growing

In the case of unburied mulch, the ground cover will prevent the development of weeds simply by smothering them.

In the case of buried mulch, mechanical work will have exposed weed seeds on the surface. These will then be exposed to their natural enemies (birds, rodents, insects). The remaining seeds will be in perfect conditions to germinate. They can then be destroyed with a second pass to ensure perfect “false seeding”.

THE ACTISOL ADVICE : the perfect sowing depth for a seed is 6 to 7 times its thickness. If mulching or false seeding is carried out at too great a depth, the seeds will germinate very slowly or not at all. There is then a risk of the seeds becoming dormant and fouling the next crop if the seed drill works to restore them to good germination conditions.

Helps combat insects and disease

The shallow burial of crop residues has a definite influence on insect pests and diseases. Exposure to cold and predators is not to their advantage, not to mention the mechanical work done beforehand.

If you would like to find out more about the Stell’Air Actisol range, arrange a demonstration or simply obtain further information, please contact us using our contact form.