Infiltrometer

One of the key information required for smart agriculture and storm watermanagement is how fast the water get infiltrated in to the soil at variousantecedent soil moisture conditions. Storm water generated from a catchmentis well routed if the portion of the rain which contributes to the runoff isproperly estimated. Infiltration data is the most important parameter requiredto estimate the runoff. Precision irrigation scheduling to prevent surfacerunoff is best estimated if infiltration rates are known for all soil types in afarm. Farmers could save a lot of resources if they are aware of the infiltrationrates of their farm soil types.The traditional way of measuring infiltration rate is time consuming and labourintensive. One would set up the infiltration measurement gear in the field witha sealed water tank which works on a principle of marriott bottle whichmaintains a constant water head. The falling water level is either measuredmanually or by a pressure transducer using data logger. The operator mayneed to stay at the site until the test is completed.Landcare Research has developed the automated, cloud connected and smartphone driven infiltrometer to measure infiltration rate at any given soilmoisture content. Up to maximum of 5 infiltrometers can be networked tomeasure infiltration rates at 5 different locations. Since they are connected tothe cloud by a cellular network there is no limitation of the distance betweendevices meaning they can be scattered in a 10,000-ha farm and monitor andcontrol from one location using a smart phone app.The basic components of the LCR infiltrometer are, measuring and spare watertanks, soil moisture sensor to measure varying soil moisture content as waterinfiltrates in to the soil, an electrode to sense the water level in the ring,pressure transducer to measure falling water height and electronics to operatevalves in order to maintain the constant water level over the soil and connectto the internet via cellular network . The water depth over the soil inside thecontainer ring is maintained at required level and the falling water level in thetank and soil moisture content are recorded with time. Infiltration ring size andthe water tank sizes can be selected to suit the soil type and can be writteninto data process in the cloud using smart phone interface. For example, claysoil requires smaller rings as infiltration rate is significantly smaller than sandysoil. Time series data are automatically recorded on a clod data base and sentto the users email account using the options given in the smart phoneinterface. Historical data are displayed on the smart phone interface as timeseries charts. Interactive charts on the smart phone allow one to determinewhen to terminate the test, for example when the infiltration rate becomessteady.The water tank level, soil moisture content battery voltage are displayed onthe interface as well. A spare water tank could be used to refill the water tankif it gets empty, which could be activated remotely. For example, sandy soilrequires a lot of water before infiltration rate reaches steady state. Theoperator will receive a warning txt message on the smart phone when thewater tank is closer to empty, so the water tank could be activated remotely.The smart phone interface also provide option to add any field notes for thelocation it is installed, for example soil and vegetation types. The basicprocedure to setup a infiltrometer network is to locate them at desired soilzones, if necessary with spare water tanks and activate and monitor from alocation which is most convenient, for example from your living room.