By lysimetry, we mean the sampling at regular intervals of the soil solution. Thanks to suction lysimeters, which are tubes fitted with porous candles, in which a vacuum of 70 to 80 bp is created. The vacuum sucks in a few hours, a few cm3 of soil solution. The rapid nitrate dosage is carried out the next day, for example, using Nitrachek. The evolution of the nitrate content makes it easy to follow in real time the balance of the complex nitrogen cycle. In other words, the credit for mineralization of soil and fertilizers minus the rate of consumption of living organisms, including our cultivated plants.