Laserfiche WebLink
Drain Gauge User's Manual <br />a Theory <br />Soil Disturbance <br />It is impossible to install the`Drain Gauge without disturb- <br />ing the soil. The goal is to install it in such a way that the <br />disturbance has minimal impact on the Gauge's ability to <br />measure deep drainage. The three factors that will affect <br />deep drainage are: changes in root uptake patterns, <br />changes in soil moisture storage, and changes in evapora- <br />tion. In some cases, it may be necessary to install the <br />Drain -Gauge beneath an undisturbed core of soil. In all <br />cases it will be necessary to allow time for roots to grow <br />back into disturbed soil. If the soil surface is tilled, there is <br />no point in trying to keep that part of the soil undisturbed, <br />since it is already disturbed. <br />Soil -Wick Contact <br />In order for the bottom of the soil profile to be under ten- <br />sion, the tension in the wick must be transferred to the <br />bottom of the soil column. There must therefore be good <br />capillary continuity between the soil column and the wick. <br />If the Drain Gauge is installed by backfilling with soil, the <br />contact is likely to be good without further effort. If an <br />undisturbed core is installed, capillary continuity is estab- <br />lished by placing a layer of diatomaceous earth over the <br />wick. The diatomaceous earth conforms to the irregulari- <br />ties of the soil and wick to provide continuity. <br />11 <br />k- <br />F <br />Ci <br />11 <br />i I <br />0 <br />