Tuesday, June 7, 2011

playing in the dirt

I found myself at the bottom of a large hole last week. We (I) have been installing Gee passive capillary wick Lysimeters that are manufactured by Decagon Devices. We are using them to try and close the water balance and provide a drainage rate so that we can calculate nitrate leaching from fertilizer use in different cropping systems. Earlier this year we installed hundreds of suction tube lysimeters, that will provide us with nitrate concentration of water that is moving into the Vadose zone. Nitrate in ground water is a pollutant that is of particular concern in many parts of the midwest and plains states.

The Gee lysimeters (commercially known as a "Drain Gauge") use a wick in a hanging column(what is in the small hole above) to provide "suction" to the soil that will (soon) fill the Divergence Control Tube (DCT, the very large PVC pipe seen above).

I personally think soil scientists are kind of nerdy, but it is pretty interesting looking at the pedology of soils in the upper midwest. People just cannot fathom the effects that glaciers had on the formation of soils.

There was a layer of "cobbles" about 38 inches down that were so smooth. It just gives you an appreciation for how things change over time.

Once I got past the cobbles I hit this really coarse sandy pea gravel that had no structure. I had dug a hole for the column of the drain gauge to go in, but when I climbed out of the hole to grab the gauge, the blickety-blank sidewalls of my hole collapsed, burying my post hole digger. Piss.

So built myself a little platform to work on.

Gauge installed and sod replaced. It takes about 9 man hours to install a drain gauge with a disturbed monolith. I had initially planned to do a undisturbed monolith, but the soil was too course, and I could not keep it in the DCT. Plus it weighed a ton. I would have never got it out of the pit by myself.

So after 2 days of digging pits by hand I headed back to WI to do the first Whitetail Ridge Thursday night race of the year. I had never been there, so I knew that it was going to be a lot of learning. The KORC crew that puts the event on is super laid back, and the trails are pretty sweet. Like a cross between Lebanon Hills in MN and Platte River SP in NE. I stopped to assist a guy that took a digger and dislocated his shoulder on the first lap. I asked him if he wanted me to reset it, but he seemed to want to go to a doctor. It would have hurt, but not nearly as much as if he had walked out and had the doc reset it once all his adrenaline had worn off. I would not have even charged him. Jumped back on the bike and chased, namely because I did not know the course. I caught a rider and he let me sit on for the rest of the lap, and showed me where the course changed after a lap. After that I came around and chased for the next 10 miles. Never saw anybody. It definitely took a lap to get comfortable on the Scale. I have spent so much time on the SS that the first lap felt twitchy and awkward, but the next two found me really getting into the groove.

Then Ali and I went out to dinner on Sat while LaLa watched the lil monster. I wore my white pants. Lookout!

Woolly Race in St Croix Falls this weekend. I prerode the course with the Cyclova-XC guys on Saturday. Looks like a lot of fun lined up for this weekend.


RD said...

st. croix is pretty nice i only been there 2 once in dead of winter and once during deer hunting season not ideal time to ride bikes on both occasions really.... sweet look don johnson maybe that's why all the references have been to drugs lately !!!!

Brian said...

Would it be OK to use a copy of the foto of your installed Gill flux meter in my presentation?

Joshua Stamper said...

Feel free to use any images, just list the photo credit as: Joshua Stamper, Minnesota Department of Agriculture. Let me know if you have any questions.