What type of soil moisture measurement is best suited for your irrigation management program? Should you use soil tension, water content, evapo-transpiration (ET), or another type of measurement? If your goal is to manage water volume, supply or pumping capacity, water content and ET might suffice. On the other hand, if your goal is to manage plant stress, optimize plant growth, agronomic results and profitability, soil tension is the best answer. Plants have the ability to self-regulate their growth based on water availability in the soil. They do so by controlling the stomata openings at the leaf surface. To avoid growth or yield loss, soil tension must be managed within a narrow bandwidth or comfort zone.