There are some good threads on Gardenweb talking about water release curves. I assume that creating one of these requires some special instrumentation that is not going to be easy to get outside of a soil lab? What I can do is measure the weight of the remaining water in a test container that I am using for porosity and water holding capacity testing. If I measure the weight of water after draining my container, then measure it again each day, I can plot out the weight or volume of remaining water until the container is dry again. That gives me an amount of water over time. Is that curve useful in any way, and could such a curve be used to generate something close to a water release curve?