Germination and humus. (Credit: Suiseisekiryu)
Researchers from the Technical University of Munich have found that the crop stagnation affecting Europe may come from poor humus, the dark organic matter in soil produced via animal and vegetable decay. The poor quality of humus may in turn come from global warming effects, according to a recent TUM press release.
Global warming may be having a couple effects on humus formation: It tends to cause humus to decompose faster, and it can also cause drought effects to increase. Either may cause a decrease in crop yield, the new study suggests. Compounding the effect is that a poor harvest in a current year will lead to lower levels of material available to create humus, which in turn will lead to poorer yield the following year.
Other compounding factors are that fertilizer use has been down and the number of livestock in Europe has been steadily declining for over 30 years, leading to less raw material for humus. In addition, legumes, a good source of material for humus, have often been omitted entirely from crop rotation cycles. Farmers have also neglected to leave crop remnants on their fields, leading to less material for humus.
Top image: Germination and humus. (Credit: Suiseisekiryu)