Chapter 19

Management of Vineyard Soils

Biological Properties

An incredible diversity of organism’s make-up the soil food web. They range in size from the tiniest onecelled bacteria, algae, fungi, and protozoa, to the more complex nematodes and micro-arthropods, to the visible earthworms, insects, small vertebrates, and plants. While some soil fauna can cause diseases in grapevines, the vast majority of soil fauna and flora are critical to soil quality. They affect soil structure and, therefore, soil erosion and water availability. They can protect grapevines from pests and diseases and are central to decomposition and nutrient cycling. The maintenance of this living aspect of the soil is essential to the maintenance of a healthy vineyard.

Bacteria

Bacteria are the most numerous type of soil organism: every gram of soil contains at least a million of these tiny one-celled organisms.

Fungi

Fungi come in many different species, sizes, and shapes in soil. Some species appear as threadlike colonies, while others are one-celled yeasts.

Nematodes

Nematodes are abundant in most soils, and only a few species are harmful to grapevines. The harmless species eat decaying plant litter, bacteria, fungi, algae, protozoa and other nematodes.

Arthropods

Arthropods are species of soil organisms that can be seen by the naked eye. Among them are sowbugs, millipedes, centipedes, slugs, snails and springtails.

Earthworms

Earthworm burrows enhance water infiltration and soil aeration. Vineyards that are “tilled” by earthworm tunneling can absorb water at a rate four to 10 times that of vineyards lacking worm tunnels.

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