Only biodiversity and the simplicity of cultivation guarantee that most diseases and pests are eliminated. If the gardener cares about biodiversity, life in the garden is in harmony, and pest and disease infestations are rare or absent.
Two types of biodiversity are important for maintaining balance and harmony in the garden (but also in the field or in the forest): biodiversity on the garden surface and biodiversity in the underground layer of the garden (soil). The harmony between them guarantees the health of the garden and thus the health and resistance of plants. There are more insects, animals and micro-organisms living in a biodiversity garden that are in balance with each other. Thanks to this, the massive occurrence of insects, referred to as pests, is difficult. Plant diseases are also reduced – healthy plants are much more resistant. Biodiversity above and below ground is achieved in different ways, but they are closely related.
6 Conditions of healthy and biodiverse soil:
- Proper fertilization, i.e. providing it with the right nutrients. The best fertilizer in a traditional ecological garden is compost. Good fertilization guarantees the right level of humus in the soil. This, in turn, ensures that the soil is healthy and remains in good condition because there is a great variety of living organisms.
- Humus. Without good levels of humus there is no way to heal the soil and maintain its biodiversity and balance. The right amount of humus is conducive to the development of mycorrhizal fungi in the soil, among others. Mycorrhizal fungi, with which almost all cultivated plants are in a certain symbiosis, have a great influence on the correct uptake of nutrients from the soil by plants.Mycorrhiza fungi are found in the greatest number around the roots of the plants, in a cylindrical sheath called rhizosphere. The rhizosphere also contains bacteria and other microorganisms. They also determine the plant’s nutrient supply. Humus also promote the development of these microorganisms.
- Correct pH. Specific plants require a specific soil reaction, with most crops, ornamental plants and trees growing best when the reaction is neutral or slightly acidic and between 6 and 7,5 pH. The organic gardener should take an interest in the pH and keep it at the right level. It is worth knowing that fertilizing with compost or other organic fertilizer makes this much easier. With mineral fertilization, maintaining the right pH level can be much more difficult.
- Cultivation in accordance with the natural rhythms determined by the cycle of the Earth around the Sun and the Moon around the Earth. These two rhythms influence the development of different micro-organisms. Also those that cause disease. Therefore it is very important to follow the right rhythm.
- The right choice of plants. Roots have a significant impact on soil biodiversity. The relationship between individual plant roots is studied by a science called allelopathy. In organic horticulture, attempts are made to take advantage of both the beneficial and adverse effects of the roots of different plants on each other. The knowledge of the size of the root systems also facilitates the proper selection of plants in coordinate cultivation systems. Around some of the underground plants, life is also very rich, various biological and physico-chemical changes are taking place, which can significantly affect soil health, as well as the content of various beneficial nutrients, structure, etc.
- Crop rotation. The proper selection of plants for cultivation is closely linked to the crop rotation. It consists in the correct, preferably as long as possible, cyclic rotation, return of a given plant to the same place in a field, bed, garden or larger field plantation. This is especially true of vegetable plants, berries, herbs and even ornamental plants, mainly flowers. The appropriate changes in vegetable cultivation systems should be considered as one of the most important elements of maintaining soil health, and thus also of reducing the risk of diseases and pests.
The right choice of plants in the form of a proper crop rotation is essential for maintaining biodiversity in the above-ground layer of the garden. It also determines the resistance of plants, their health and yield. It also allows the best use of natural atmospheric factors necessary for growth.
The right light, air and temperature also have a great influence on biodiversity and thus on plant health and resistance. The gardener can consciously regulate the influence of these factors by selecting plants on beds or by performing certain cultivation procedures. It is best to select local plants, appropriate for a given environment, climate and soil type, light and thermal conditions. This also makes it easier to regulate the possible negative effects of extreme events. For example: the effects of drought are eliminated by watering, but also by tillage, e.g. sprinkling, mulching. Excess water in the soil can also be reduced by means of tillage (e.g. soil movement), which increases evaporation and dries the soil. The influence of the wind can be reduced by using cover crops. In turn, the strip tillage system, the coordinates, makes good use of light.