*4.2.2 Mineral nutrients addition*

Plants need minimum 17 mineral nutrients divided into macro- and micronutrients to grow and complete plants' life cycle. Each of the nutrients perform specific functions within the plant and the amount of each needed by the plant depends on what role the plant has each element [53, 54]. Microelements are needed in a small amount, but they are as important as macro-elements. Micronutrient deficiencies induce stress in plants, cause yield losses, resulting in poor health for animals and humans [29]. Supplying plants with micronutrients, through soil application or foliar spray, increases yields, produces higher quality, but also increases macronutrient use efficiencies. Micronutrients application is cheaper and needs less labor and transport because there are small quantities to manipulate. There are nine macronutrients nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), carbon (C), oxygen (O), and hydrogen (H) from which conventional agriculture is using six, but focus only on three N, P, K. Farmers in conventional agriculture,

concentrating on NPK, can deliver excellent yields in irrigated conditions or rainy years, but less quality is usually obtained. Finite products, full of nutrients, for healthy animals and humans, are obtained when plants absorb balanced nutrients. To design a fertilizer plan, one need proper knowledge of the interaction between nutrients [55]. The key to controlling the mineral nutrients is restoring the soil food web. First-year must fertilize with biofertilizers and 70% of the recommended macronutrients N and P to obtain better yields and better-quality crops, low nitrate and nitrite levels in crops [56]. In two-three years, with a soil food web restored, microorganisms will takecare of plant nutrition, bacteria will fix the nitrogen in the soil, while other specific bacteria will solubilize the needed minerals. Biofertilizer is keeping beneficial microorganisms in the soil healthy and allow plants to overcome the drought [57].
