In plant production, nitrogen is a key mineral nutrient to increase quantity and quality of the crop and therefore, is added as fertilizer to most of the crops. However, the total amount of nitrogen supplied, is not taken up by the plants and used for their metabolism and growth. The excess amounts of nitrogen are transformed to forms that are lost from the soil. Nitrogen occurs in the soil in different forms. It is released from organic matter by mineralization. The resulting ammonium ion (NH4+) is converted into nitrate (NO3-) by nitrification. Both forms, ammonium and nitrate, can be taken up by plant root cells. In most agricultural soils, nitrification occurs rapidly and therefore nitrate is the predominant form of nitrogen in mineral nutrition. However, nitrate is lost from the soil due to its high mobility, which contributes to leaching into groundwater, and due to its conversion to nitrogen oxides and N2. In crop production we try to limit these losses by slowing down nitrification by using inhibitors of nitrification. In nature, too, some plant species release compounds with a similar function to the rhizosphere to optimize their mineral nutrition. In my bachelor thesis, I will present the importance of nitrification inhibition for plant mineral nutrition and the possible use of nitrification inhibitors in crop production. I will present the effects of these applications on crop yields and discuss their potential to reduce the negative impact of nitrogen fertilization on the environment.
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