Researchers Reveal Molecular Mechanisms That Bind Water and Soil
Water molecules form bridges between mineral and carbohydrates to lock in moisture, study finds. From lifelong farmers to backyard gardeners, most plant-lovers know that adding organic matter to a field, vegetable plot or flowerpot increases the soil’s moisture. Now, for the first time, Northwestern University scientists have uncovered the molecular mechanisms that enable organic matter to boost soil’s ability to retain water — even in desert-like conditions. Carbohydrates — key components of plants and microbes — act like a molecular glue, using water to form sticky bridges between organic molecules and soil minerals, the team found. These bridges lock in moisture that otherwise might evaporate. The discovery sheds light onto how soils stay moist during drought and even how water might have survived for billions of years trapped in otherworldly rocks, including on Mars and in meteorites. To conduct the study, Aristilde’s team mixed a common clay mineral (smectite) fo...