Scientific American 1920 – Fertilizing the Air with Carbon Dioxide to Promote Plant Growth

In 1920, Scientific American reported that there was not enough CO2 in the atmosphere and that crop yields could be greatly improved by CO2 emissions from chimneys, and that the land was covered in dense forests when CO2 levels were much higher.

Carbon dioxide for air fertilization
Dr. Alfred Gradenwitz

One of the main constituents that make up the body of a plant is the carbon atom, which makes up about one half of its organic matter. The opinion that this carbon comes from the soil has long been rejected, modern research has shown that atmospheric carbon dioxide is absorbed by chlorophyll and converted into organic compounds.

While atmospheric air is currently relatively poor in carbon dioxide, of which it contains only about 0.03 percent, in the early period of our planet’s development, when it was covered with dense forests from which our coal deposits originate, it contained incomparably more of this gas.

This fact suggested an increase in soil fertility by increasing the content of carbon dioxide in it and creating conditions reminiscent of the conditions of antediluvian eras. For such a process to be carried out on any production line, of course, a cheap source of carbonic acid was required.

This was discovered by Dr. Fr. Riedel from Essen-an-Ruhr in the flue gases escaping from all factories, but mainly from blast furnaces, which until now have been allowed to escape into the atmosphere without any useful purpose. Accordingly, he set about developing a process for which patents were obtained and which was subjected to practical trials on a large scale.

First, three greenhouses were built, one of which was used as a test and the other two were used for testing. The test room was supplied with cleaned and burned-out blast furnace off-gases through a punctured pipeline that traversed the entire greenhouse in the forward and reverse direction. Gas delivery began on June 12, when plant growth was in full swing.

Through careful cleaning and complete removal of components such as sulfur, the gas was found to have no harmful effects. In contrast, even a few days after the start of the test, more lush vegetation could be observed in the test room than in the control rooms. It was found that castor bean leaves in a gas-powered greenhouse were more than one meter wide, while the largest leaf in the control rooms was only about 58 centimeters wide.

Plants exposed to carbon dioxide also showed marked growth progress. With tomatoes planted in another part of the greenhouse, a yield of 29.5 kg was obtained for a given number of fruits, while the weight of the same number of fruits in the test chamber was 81.3 kg, that is, 175% more.

With the simultaneous sowing of cucumbers, a slightly smaller difference was noted: the yield in the control chambers was 138 kg, and in the test chamber – 235 kg, which corresponds to an increase in yield by 70%. In this regard, an interesting phenomenon was noted: while the cucumbers in the control rooms had bright spots, on the cucumbers in the control rooms, due to the more abundant formation of chlorophylls, they were completely dark green in color.

Simultaneously with these tests in the greenhouse, experiments were carried out in the open air: a square plot of land was surrounded by punctured cement pipes, from which exhaust gases were continuously emitted.

The wind, which mainly strikes the ground at an angle, will direct the carbon dioxide in an alternating direction towards the plants, which allows the supply of fertilizer gas to large areas. On the opposite side of the greenhouse, a plot of the same size, which was not exposed to carbon dioxide, was provided for inspection, while the soil in the two plots was of the same quality. Samples were taken from the best parts of the test field, but from the center of the field exposed to carbon dioxide, the yields for spinach are 150 percent, potatoes 180 percent, lupines (legumes) 174 percent, and barley 100 percent.

Potatoes in the field that have been exposed to carbon dioxide ripen much faster than in the control plot.

In view of these surprisingly favorable results, the test site was eventually expanded, three greenhouses of the same size as the existing ones were added, while a small area of ​​open ground was significantly enlarged and a larger area of ​​30,000 square meters was equipped underground central pipe and branch pipes in long sections. Particularly favorable results were obtained in this field with potatoes: 300% growth was recorded in connection with large-scale trials.

All the experiments carried out so far show that fertilizing the air with carbon dioxide is a much more efficient process than even enhancing the fertilization of the soil with sustainable manure and cow dung.

According to Dr. Riedel’s calculations, the metallurgical plant, which has about 4,000 tons of coke per day on its blast furnaces, will daily produce up to 35 million cubic meters of flue gases containing 20 percent of carbon dioxide. This is such a huge amount that even in the case of partial use, it will be enough for vast tracts of land.

Therefore, Dr. Riedel believes that work to produce carbon dioxide to supply agriculture will soon become as commonplace as work to produce electricity and gas, while large industrial centers will at the same time become centers of increased agricultural production.

Careful analysis has shown that the percentage of carbon dioxide in the air remains well below the limit at which the gas becomes hazardous to human health.

Notify of
Inline Feedbacks
View all comments
Would love your thoughts, please comment.x