What Plants Talk About
The title of this documentary is misleading, as it focuses more on plant behavior than on plant communication. The latter is surprisingly similar to animal behavior in many respects. Research shows plants forage for food (via their roots), just as animals do. Like animals they also have complex social relationships with other plants. Not only do they compete aggressively with other plants for light and nutrients, but they share nutrients with sister plants and band together to fight off predators. For example, plants give off distress hormones when they’re attacked, and selective plants (such as lupins) give off noxious substances that protect all the plants around them.
In forests, mother trees have bee found to nurture daughter trees that are too shaded to produce their own sugars via photosynthesis. By injecting large mother trees with carbon-14, scientists discovered they were transferring sugars through their roots to young saplings that surrounded them.
In a forest trees establish vast cooperative networks with fungi that exchange nutrients they capture from soil for the sugars trees produce.
These complex networks are destroyed by industrial agriculture. Plowing and heavy use of synthetic fertilizers, pesticides and herbicides destroy the vast fungal network essential for healthy plant growth. This is the main reason why organic farming – which preserves vital soil organisms – produces much higher overall yields than industrial agriculture.