Kohlensäuredüngung, Humus und Maximalerträge

Summary

A comparison of the most modern textbooks of plant physiology with those from the beginning of the century shows that to-day fertilizing with carbonic acid is an accepted fact, at least in cultures made under glass. But fertilizing is also done with cultures in the open and in agriculture with the help of this nutrient gas, which develops out of the ground through microbiotic processes on materials containing carbon, often called for short “humus”. Between these processes, and leaf respiration on the one hand and the assimilation of the green on the other, follows a variable equilibrium in respect to the no longer utilizable carbonic acid of the atmosphere. Maximal yields are unobtainable when these relations are not taken into account. Some basic methods for reaching maximal yields are described.