Vines: the most effective fertilisation of a vital soil

The soil is the substrate from which plants absorb water and nutrients via their root systems, which also has the—perhaps more obvious but equally important function—of anchoring the plant to the ground.

But the function and importance of soil in agriculture certainly do not end here.

The importance of preserving and increasing the fertility of cultivated land in all its facets—chemical, physical and biological—is universally accepted and is also one of the principles that bring together the various productive philosophies in agriculture, and more specifically in viticulture: integrated and organic as well as biodynamic and natural.

Vital and balanced soil nourishes the plant more efficiently while leading to more efficient absorption and use of substances administered through fertilisation. But there’s more—it creates favourable conditions for the establishment and multiplication of meso- and microfauna that are useful to plants, both because they facilitate their nutrition and have a positive effect on their phytosanitary status.

According to Palliotti et al. (Manuale di Viticoltura, Edagricole), “Mineral nutrition is the physiological process by which plants absorb nutrients in an inorganic form, primarily from the soil through the roots, and secondarily via the leaves through the stomata. Mineral nutrition also refers to the metabolic transformation of the substances absorbed by plants as they are translocated to various organs to take part in biological functions.”

Fertilisation, on the other hand, is the set of techniques that guarantee plants adequate nutrition in terms of macro- and microelements, according to farmers’ goals. In viticulture in particular, “modern” soil fertilisation aims to improve the chemical-physical and biological characteristics of soil and its “habitability” for the roots by distributing organic substance, mineral fertilisers, organo-mineral fertilisers and compounds based on useful micro-organisms. It’s worth emphasising here that an adequate supply of organic substance helps maintain a favourable soil structure, which in turn provides porosity that promotes circulation of air and water in the soil, both essential for root activity and the biological vitality of the soil.

Fertilisation can be carried out during different phases. Pre-planting base fertilisation can be followed by applications throughout the productive life of the vineyard. The number of applications per year and their timing vary according to the specific nutritional needs of the vineyard (which, in turn depend on farmers’ objectives, the phenological phase and the vegetative-productive state of the plant), the vintage, the type of fertiliser used (granular or liquid, fast-acting or controlled-release) and the type of application (soil, fertigation, foliar fertilisation).

Over the past twenty years, there has been a sharp increase in interest in soil microbiomes and the usefulness that various consortia of microorganisms can have in rationalising fertilisation and crop protection. Numerous species of bacteria, fungi, algae, protozoa and nematodes, as well as microarthropods and insects, inhabit the soil and rhizosphere, establishing different forms of interaction with each other and with plants’ roots: symbiosis, parasitism, and antagonism. Among the useful microorganisms that live in the soil are those that promote the availability of nutrients and those that increase their absorption (such as mycorrhizal fungi), as well as those that penetrate from the rhizosphere into the plant (endosphere), positively influencing its physiology.

Regular analysis of vineyard soil is essential in understanding its mineral composition and organic matter content (grain size and structure). Such studies must be carried out before planting and repeated throughout the life of the vineyard, throughout which the soil may be depleted not only by removal by the vines but also by incorrect agronomic practices (such as excessive tilling or compaction) erosion and leaching, volatilization, or insolubilisation of nutrients.

To establish an effective fertilisation strategy, assessment of a soil’s nutritional potential and physical characteristics must be accompanied by an evaluation of the plant’s nutritional status, based both on visual observation—periodic monitoring of the vineyard is essential to prevent any critical issues—and on analysis of leaves, petioles and possibly pruned wood.

Only with such measurements and data is it possible to preserve the soil’s fertility, the plant’s vegetative-productive balance and the quality of the grapes while making fertilisation sustainable from an economic and environmental point of view.

One must also take into account that a plant’s peak absorption of certain elements does not always coincide with the availability of the element in the soil, be it from natural supply or fertilisation.

An effective fertilisation strategy therefore includes different types of products and measures, as well as good agronomic practices to preserve the soil.

The Terrapiù line by Agribios offers four products for the fertilisation of table grapes and wine grape vineyards, containing high quality organic substance, hydrolysates of various kinds and useful microorganisms.

AGRI BIO AKTIV is a soil regenerator—in addition to providing organic substance and nutrients, it promotes and directs the proliferation of microorganisms that are useful in plant development. Its particular microbial composition, rich in Trichoderma, acts on the soil and on the root, and limits the development of pathogens responsible for some root system diseases by antagonism.

BIOPHOS is a multifunctional organic fertiliser that provides humified organic substance and a specific pool of bacteria from the rhizosphere that act on the phosphorus present in the soil, making it available to the crops while preventing retrogradation to insoluble forms of the element thanks to the action of alkaline phosphatases and phytases produced by microorganisms contained in the product.

MICROTECH START is a liquid organic fertiliser, 100% plant origin, designed for the initial phases of the crop (regrowth phase of multi-year crops). It provides the primary nutritional elements (nitrogen, phosphorus and potassium) as well as organic carbon, enzymes, sugars, laevorotatory

amino acids, peptones, mycorrhizae and rhizosphere bacteria useful to plants (PGPR, nitrogen fixers, and more).

MICROTECH START’s microbial composition—containing Trichoderma harzianum,

Trichoderma viride, Bacillus subtilis, Bacillus megaterium, Azospirilli, Stremptomyces and other microorganisms—has been specially formulated to protect the root in the early stages of development, biostimulate the crop and improve the absorption of nutrients supplied or already present in the soil but not used.

MICROTECH POWER is a liquid organic fertiliser containing mycorrhizal bacteria and fungi—Trichoderma harzianum, Trichoderma viride, Azospirilli, Azotobacter and Pseudomonas), as well as other microorganisms—to be used during the cultivation phases of all herbaceous and tree crops. It provides nitrogen, organic carbon, enzymes, sugars, laevorotatory amino acids, peptones, mycorrhizae and rhizosphere bacteria that are useful for plants (PGPR, nitrogen fixers, and more). Made using an exclusive enzymatic hydrolysis process, MICROTECH POWER biostimulates plants by facilitating the absorption of the supplied nutrients, creating a protective barrier around the roots and strengthening the plants’ defences against biotic and abiotic stresses.