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NOTE: To get off this list, send email to majordomo@aqua.ccwr.ac.za with the body of the message containing the line: unsubscribe sowacs An additional measure of caution: Using electronic readout tensiometers, watch out for the thermal expansion/contraction of the air bubble, as tiny as it may be. That may introduce sizable diurnal fluctuation, unrelated to actual soil water tension changes. Moshe Meron MIGAL Israel >Dear James: > > >I would like to caution that many of the "diurnal" or "diel" >changes in soil water content and potential in soil profiles, especially at >depth, are many times an electronic/thermal phenomenon created within >the datalogger or sensor itself. Nearly all electronic components >have thermal sensitivities. Manufacturers attempt to compensate for >these, and generally do good, but not perfect jobs. > > These effects need to be sorted out by conducting background >tests using independent, and perferrably nonelectronic, >measurements or by using "dummy" sensors that do not change >reading with water content. > >Rick Allen >Univ. Idaho > >> Dear subscribers, >> >> I am a student in the UK and am concentrating my study on the >>diurnal changes of soil moisture at depth, deeper than 60cm's >>in the soil. >> >> Could you point me in the right direction for references which >>deal with diurnal 'recharge' in soil moisture, or 'overnight >>resorption'. >> >> Many thanks for any help >> >> James A. Dalton