**3. Principles of restoring soil and plants health**

Regenerative Agriculture is organic agriculture, using only natural available resources. In organic agriculture, farmers are certified if they produce non-GMO plants without using synthetic chemicals, approaching soil conservation and preservation for biodiversity. Farmers are allowed to use only inputs from certified organic agriculture. In 2018, at Rodale Institute was introduced for the first time a new higher standard for the farmers working in a regenerative system called Regenerative Organic Certified (ROC) [35]. Regenerative Agriculture is the way to sustainable farming practice, regenerate soil fertility, grow healthy plants that create healthy soils, less sensible to draught. Using methods from Regenerative Agriculture technology, carbon is sequestered in the soil, soil structure and soil fertility improve, water retention, and crop yield increase, while drought and flood ameliorate [36]. Regenerative agriculture can be defined by a holistic system approach that starts with the soil characteristics and also includes the health of the plants, animals, farmers, and community. The main aims envisage to regenerate topsoil, restoring degraded soil biodiversity, enhancing ecosystem services, improving water cycling and improving the resilience of soil to extreme weather. Regenerative Agriculture focuses on improving soil health by following four main mandatory principles and one optional. All specialists in Regenerative Agriculture accept the four principles that include soil cover, living roots, biodiversity, and minimalizing soil disturbance. The last principle which is the integration of animals is partially accepted and can be even more important in a few specific situations.

Everything plants need is cycled by soil microorganisms before becoming available to plants' roots. Earth life is based on photosynthesis, a process that transforms photonic energy into chemical energy. It varies, depending on the availability of light, water, carbon dioxide, chlorophyll concentration, and plant nutrition. Photosynthesis is the most efficient cycle and sustainable process in nature [37, 38], and it is the engine we can rely in Regenerative Agriculture. Farmers know that water, nitrogen, and high-temperature influence the photosynthesis process. During drought, plants switch from photosynthesis to photo-respiration process, when are consuming their reserve of proteins [39]. To avoid this happening, proper management has to be used that optimize nutrition. When monitoring fields frequently, one should notice nature needs [40].
