Smart Farming: How Microbes Help Our Crops
The microbial communities on and around plants are critical to manufacturing the nutrients that plants need in order to grow. Certain bacteria convert atmospheric nitrogen into ammonia, a form that is readily usable by plants and animals. Other soil microbes recycle nutrients from decaying plants and animals, while still others convert elements, such as iron and manganese, to forms that can be used for plant nutrition. However, it takes a community to perform these critical biotransformations. For example, no one microbe is capable of converting ammonia to nitrate, yet teams of microbes do this very efficiently.
Keeping Crops Healthy
One of the most valuable but least understood mysteries of farming is the "suppressive soil" phenomenon. In suppressive soils, plants stay healthy even when disease-causing organisms are present in high densities. If this soil is sterilized, killing helpful and harmful microbes alike, plants can become sick and die once the pathogens find their way back into the soil. Scientists speculate that microbes living in the suppressive soil actually protect plants from diseases—and if these microbes disappear, plants are far more susceptible to infection. Despite decades of research, scientists have only been able to pinpoint the microbes responsible for suppressing disease in a few locations. Scientists believe that a complex microbial community is responsible for suppressing disease, because no single microbial species can do it alone. The activities of suppressive soil communities are enormously beneficial to agriculture.
While scientists have been able to glimpse the complex microbial communities that help keep crops healthy and productive, much about those communities remains mysterious. What we do know is that by using certain microbes we can get improve soil fertility and improve plant yield, making an effective organic fertiliser.