*2.1.4 Excess of synthetic fertilizers*

Synthetic fertilizers suppress biology [18], contributing to soil compacting, loss of fertility, and humus total rate decrease. Plants are using only 15–30% of total inorganic fertilizers, while the rest is leaching in lakes, rivers, groundwater, etc. Accumulation of nitrogen in groundwater has different sources, being caught in irrigation lakes [19, 20]. As groundwater is the main source of drinking water, contamination poses several human health problems. At present in the United States of America, there are used 20 times more chemicals than in the American Dust Bowl period, and soil degradation continues dramatically.
