Hügelkultur is the practice of burying large volumes of wood to increase soil water retention. The porous structure of wood acts as a sponge when decomposing underground. During the rainy season, masses of buried wood can absorb enough water to sustain crops through the dry season. Start by using fallen tree limbs, branches, logs and whole trees and simply burying them. Pictures are from a sequence of building a hugelkulture bed. Click on the following is a link for instructions on how to build a hugelkultur bed. http://www.richsoil.com/hugelkultur/