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Dear Pat, Ron, or any other Moisture Point user: We also have "recently invested heavily" in the MP system. I appreciate the chance to dialogue with you about your experience with it. (This is a great forum!) Like you, Ron, it is a little early for us to share too many conclusions and offer many "tips and tricks". We used the MP with only a few clients during the summer of '96, to get our feet wet (pun intended) and become more comfortable with the technology. This summer we intend to increase our use. Some background on who we are and our goals: Agrimanagement is a private agricultural consulting firm in Yakima, Washington. We have provided a scientific irrigation scheduling service to farmers and orchardists since 1966. As we have done in the past, we continue to use gravimetric coring as our main tool. At the beginning of an irrigation season, we will establish a representative sample strip and take cores throughout. Our data therefore reflects the average of a given area, as opposed to a fixed point. We also have the flexibility to vary a sample strip, as necessary, in a given week. The samples are then baked in our office ovens overnight and the "% moisture by weight" data is fed into the computer the next morning. Growers usually get their data along with our recommendations the day after sampling. While we have always experimented with different types of soil moisture measurement technology, we have always seemed to come back to the old standby of sending a crew of college students out to a client's field with a soil probe and hammer to collect soils down to 4' (depending on crop). (I remember those days with fondness, :-- at least I was in shape back then!) TDR technology has intrigued us because it appears easy to work with and doesn't involve a nuclear handling license. Once the probes are in the ground, the system is also pretty mobile, we can carry it from one client's field to the next. We think that it will be more practical in permanent crop situations (orchards, vineyards) where there isn't a plow coming through all the time to run over the rods. We are hoping the MP will prove to be a good alternative to gravimetric. We have purchased mainly type "F", "L", and "A" probes. I must say that the technical support people at GS Gable, the manufacturer, have been very helpful and responsive. Pat, regarding the MP rods, you said, >You insert this (with some difficulty in clay soils) in the soil... >Problems occur with the probe bending when inserted into the soil, and >with inaccurate soil moisture measurements in layered soils.
Yes, this is of concern to us, especially as we will perhaps be removing them and installing them in new locations from season to season. We deal with the whole range of soil types. While you can always replace a rod, they are not cheap. By the way, Pat, what is your background and use of the probes? Ron, you said: >By the way, we would like to see one thing re-designed on the >MoisturePoint system. Instead of having the connecting cable >permanently or semi-permanently attached to the "smart box", you have to >screw the coupling on each time you head to the field (the box enclosure >does not allow you to leave the cable connected). This may not sound like >a big deal, but the connection seems to be a tight fit and a bit tedious to >accomplish. The connection at the probe end presents no problems. I know exactly what you mean! GS Gable was able to give us some good advise: pushing down on the base of the connector as you screw it on seems to help, or alternatively, pulling up on it as you screw it off. It is dangerous to run around with the cable connected to the "blue box" console as the lid could accidentally fall down on the cable and potentially do damage to it. This design, though, is very rugged and water resistent. We feel confident taking the blue box into the often wet and muddy environments that we take it to. >One other thing -- some suggest that you should use texture-specific >calibrations for the MoisturePoint TDR. We plan to look at this, and >would welcome comments/suggestions from others. We are also investigating this, Ron, but we haven't done our own testing. Let's stay in touch! Sincerely, +------------------------------+ | David W. Marshall | | Agricultural Economist | | Agrimanagement, Inc. | | P.O. Box 583 | | Yakima, WA 98907 | | Phone: (509) 453-4851 | | Fax: (509) 452-6760 | | email: agrimgt@televar.com | | | | "Measuring Crop Needs for | | Greater Profits." | +------------------------------+