*4.2.6 Cover crops*

The presence of plant cover crops in the agricultural system aids in the production of large amounts of biomass. This boosts the soil's organic content, improving fertilization. The physical, chemical and biological qualities of the soil are improved by maintaining permanent cover crops, and in time, contributing to the restoration of its health. It is recommended to use biodiversity, which include at least one species of leguminous plants. Inoculation has to be achieved with nitrogen-fixing bacteria, especially for leguminous plants. Then the amendments can be spread and may plant various cover crop seeds. Incorporation of amendments can be done with a disk harrow, while the cover crops may consist of oats, rye, buckwheat, radish, mustard, vetch, clover, etc. Plants' biodiversity will attract various bacteria and fungi, each plant species attracting its own specific microorganisms. In this way, the soil food web will be restored sooner and better. Cover crops have to be chopped or mowed in spring before full bloom, and a minimum of two weeks before planting the main crop. The cover crop will maintain the soil moisture, while soil temperature will not vary too much during drought or between day and night. After mowing, cover crops are used as mulch. Raindrop energy will be dissipated by living crops and mulch, and in this way, erosion will be under control. Cover crops are being decomposed by fungi and bacteria. Another advantage is that in winter cover crops are one of the best options to defend against topsoil loss due to erosion. If it is managed correctly, the decomposition of cover crops by bacteria and fungi provides nutrients to the main crop (cash crop), while biodiversity of cover crop suppresses weeds, prevents NO3 leaching and produces above-ground biomass N [64, 65]. Plant diversity helps to reduce pathogens, pests, and weed invasion, reducing the need for insecticides and pesticides.

A diversified crop rotation enhances soil structure by varying the length of planting zones, allowing for better water penetration. Different crops with varying nutrient requirements, as well as waste products, will help to create a more balanced and resilient soil ecosystem. The duration of these rotations is usually between 4 and 6 years.
