Researchers at the universities of Kassel and Bonn show that soil pathogens spread after heat and drought stress.
Climate change is affecting the health of agricultural soils. Increased heat and drought make life easy for the pathogenic fungus Pythium ultimum. As an international team of researchers led by the Universities of Kassel and Bonn has shown, the fungus causes almost total crop failure in peas after a hot and dry stress event. Short-term soil recovery seems to be possible only in exceptional cases. The study has now been published in the journal "Applied Soil Ecology".
Pythium ultimum is an aggressive fungus that is transmitted through the soil and infects the roots in the seedling of important agricultural crops such as beets and peas but also corn, soybeans and potatoes. The plants develop root rot and die. "In some cases, there may be a total failure of the germinating seedlings," states Dr. Christian Bruns of the Section of Organic Farming and Cropping Systems at the University of Kassel. However, soils also have protective mechanisms against these pathogens. Certain fungi act like "bodyguards” and protect the roots of plants, while some microorganisms parasitize the harmful fungus or simply consume it.
The scientists took soil samples from very different locations in cool and damp Scotland, temperate northeast Germany and dry and warm eastern Hungary. The soil samples, including the microorganisms living there, were put under stress in climate chambers with heat (40 degrees Celsius) and drought (only half soil moisture) and then infected with the aggressive fungus Pythium ultimum. The researchers investigated the effects of this stress event on the pathogen and ultimately the plants by subsequently sowing peas in these pre-treated soils.
Read more at University of Bonn
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