Garden with Insight v1.0 Help: wilting point

The wilting point of a soil is the amount of water held in the soil that is strictly unavailable to plants not adapted to a desert environment. When most plants are in a soil at its wilting point, they will wilt to the point that they cannot recover. About 40 to 60 percent of the water in the soil at its field capacity is unavailable to plants because it is held very tightly in very small soil pore spaces (called micropores). If you think of the soil like a sponge, the wilting point is like the amount of water the sponge has left after you have wrung it out.

In this simulation wilting point is input as a parameter for each soil layer. It is changed only when the proportion of rocks in the layer (particles bigger than sand particles) is changed. When the soil is mixed, the wilting point of some layers may change due to mixing of the soil particles. Wilting point, field capacity, and porosity are used extensively in the model as standards against which to compare the soil's current water content.