Burying fertilisers and soil conditioners

The correct fertilisation of vineyards has a significant effect on productivity. You, therefore, need a good understanding of the soil and subsoil and to work with equipment that ensures the optimal distribution of nutrients.

For example, not all vineyards have the same nutritional needs. Although it is true that the vines always need the same nutrients, understanding which elements are already naturally present in the soil or which ones are scarce and, therefore, need to be supplemented with a specific fertiliser, is far a more complicated process. It is, therefore, a good idea to perform a soil analysis at least once every three to four years to check of the state of fertility.

Expert winegrowers and viticulture technicians can make use of soil investigations and perform physical and chemical analyses of the vineyard, with the support of laboratories, to identify any deficiencies in or excesses of nitrogen, potassium, magnesium, iron and boron.

Having ascertained what is needed, three types of fertilisation can be determined for the vineyard, based on the period of life:

• basic fertilisation, to be carried out before planting the vines when working the soil;
• growth fertilisation, to be repeated every year until the plant has reached full maturity, around the third year after planting;
• production fertilisation, on adult and productive plants.

Basic or pre-planting fertilisation is required to enrich the deeper layers of the soil with organic substances and mineral elements.

The first fertiliser to use is mature manure (organic fertilisation), to which elements such as phosphorus and potassium (mineral fertilisation) should be added, to ensure penetration deep in the soil.

The growth or starting fertilisation is carried out from the second year after planting to stimulate the formation of the productive structure, through the introduction of nitrogen. It is not included in the basic fertilisation because the plant does not yet have a sufficient root system and the nitrogen would be dispersed without being absorbed.

The ideal period for growth fertilisation is autumn and the quantities of nitrogen are determined based on the vigour of the vine and the characteristics of the soil.

The production fertilisation, on the other hand, is carried out from the 3rd year onwards in two stages: during the vegetative stage (two fertiliser applications) with the addition of magnesium, and secondly (with only one application) at the end of September with high concentrations of phosphorus and potassium.

The quantities of elements required for fertilisation must be determined based on the nutritional needs of the soil.

Foliar fertilisation is another technique and also plays an important role in viticulture, supplementing (only in some cases) the fertilisation of the soil with the administration of macroelements or microelements in a completely soluble form.

If you have a localised (drip) irrigation system, fertigation is very useful. This is a technique that allows fertilisers to be distributed together with the irrigation water, creating a combined effect between the water and fertiliser.

Lastly, green manure should not be overlooked, an age-old technique that has been rediscovered in recent times, especially in conservative agriculture techniques.

Considered to be a green fertilisation technique, it is used to increase soil fertility (significant increases in nitrogen at a low cost) by ploughing in pure or associated herbaceous crops. It is called green fertilisation because it is done only with plants without the addition of substances of animal origin. The biomass, once underground, decomposes thanks to the microorganisms that inhabit the soil, and provides natural nourishment to the cultivated plants.

The green manure technique is a very effective practice not only for horticulture, but when fertility needs to be restored to the land following intense farming.

In general, preference should be given to crops that are able to colonise the soil quickly and produce maximum biomass in the period between the sowing of the green manure and the planting of the crop that will benefit from it. Among the most widely-used species there are many varieties of legumes (lupine, field bean, clover, vetch, sainfoin, etc.) but buckwheat, barley, horseradish, mustard and nectar source plants are also used. Undoubtedly, the green manure of legumes results to the best results in terms of nitrogen enrichment.

The best time for the uptake of biomass into the soil is normally when the cover crop is in the pre-flowering stage. Care should be taken not to allow the stems of the plants to become overly lignified which, once ploughed in, would take too long to decompose and return the substances to the soil. It is in that stage that green manure plants have reached their maximum development and the percentage of fibres in their tissues begins to grow, also increasing the C/N ratio (carbon/nitrogen), together with the transfer of nutrients.

The incorporation of green manure can be carried out in different ways by ploughing, subsoiling, digging in or even with surface work. In some cases, it is also possible to avoid burying the green manure and use it as mulch when working the ground to thus control the proliferation of weeds.

The process of burying fertilisers of biological or mineral origin can be done through the use of different types of equipment developed by Sicma specifically for these purposes.

For basic fertilisation, Sicma recommends its wide range of ploughs to allow the soil to be worked after harvesting. The goal is, in fact, to eliminate weeds and, above all, plant residue from the previous crop, burying them deep in the ground, so they do not interfere with the growth of future new seedlings. The range differs according to the ploughing depth, so ploughs suitable for surface (10-20 cm), medium-depth (from 20 to 30 cm) and lastly, deep (within 50 cm) tillage are available. The ploughs can also be equipped with two or more ploughshares, in or out of the furrow, including rapid movement, with optional depth wheels and mouldboard skimmers.

After ploughing, the ground is covered with fertiliser using Sicma “Toro” mechanical and “Mila” pneumatic seeders, both of which can be applied to the three harrow models of the EA-EV-EC series. This type of machine allows you to level and break up the loose soil by burying the fertiliser.

One of the solutions that Sicma offers to optimise the burying of fertiliser with a single pass is the tank for burying UVC fertiliser consisting of a subsoiler which is ideal for medium-deep work, fitted with pairs of anchors, front discs, rollers and adjustable flow control. Lastly, for more accurate processing, Sicma also offers the UVS spreader tank designed to bury pellet and granular fertilisers, which can be attached to the PR and PRX series subsoilers. The tanks of the UVC and UVS series can not only be sized to the operator’s specification, but are also equipped with dosers which dispense the fertiliser into the ground whilst adjusting the speed of the flow (in the UVS model) after creating the furrow.

Lastly, spading machines can also be used for the “green manure” technique as another way of burying green manure.  Spading machines turn over the clods earth by the alternate movement of the spades, allowing the green manure crop residue to be pushed deep into the ground where it will begin to release the fertilising nutrients.