Anyone who grows plants knows that to keep your plants alive, they must have sufficient water. Water is one of the most limiting factors for plants. By understanding how plants use and intake water, watering systems can be developed to optimize plant growth. Plants have evolved with the goal of capturing water in the soil; a successful plant is able to find water, capture this water, and transport the water to its leaves for use. One way that plants do this is by undergoing hydrotropism, where roots grow toward underground water sources. Once a plant has located water, and grown to get to it, it begins the process of transporting the water from the roots all the way through the plant to the plant leaf where it is used for photosynthesis.
Water is transported from the plant roots to the plant leaves through a mechanism called cohesion-tension. Cohesion-tension is the process that raises water from the roots to the leaves of a plant. As water molecules are pulled into the root tips of a plant, the molecules form a chain, held together through the cohesion of hydrogen bonds. This chain is pulled upward under the tension created by the evaporation of water in the plant leaves. As water flows upward through the plant, it travels through specialized plant xylem cells, which act like a microscopic straw. After moving upward through multiple of these connected tubes, the water eventually reaches the leaf. When a plant is dehydrated, these tubes can collapse or the water chain breaks, creating an air embolism within it. The only way the plant can fix these blockages is to divert the water chain to a new xylem tube, or to grow an entirely new one.
Plants intake water very slowly, through chains of water molecules. Once these chains are broken it takes a lot of resources for the plant to fix the problem, resources that should be going toward growing. For the best and most rapid growth, a plant should have access to a constant source of water, ensuring there is never a water deficit. This water should be provided at exactly the same rate as the plant can intake it, otherwise there will be water waste through evaporation, runoff, and loss into the soil. The Horto-Logic device being developed releases water constantly and extremely slowly, at a rate comparable to that which plants can absorb it, allowing plants the best growth possible.
Grace Gardner
Horto-Logic Intern
MIT Class of 2022
About Me:
My name is Grace Gardner and I’m a Horto-Logic Intern. I’m studying aerospace engineering at the Massachusetts Institute of Technology. I joined Nick Cook in May 2019, and have been working in a capacity as an engineering intern. In my spare time, I am passionate about competitive rowing, and enjoy learning about science and the application of technology.