Gravimetric processing from samples taken using corer.
| Date/Time | Location | Tare (g) | Wet (g) | Dry (g) | Density (g/cm^3) | Qsoil (cm^3/cm^3) % | EC5 Reading (cm^3/cm^3) % | Diff (cm^3/cm^3) % |
|---|---|---|---|---|---|---|---|---|
| 20 Feb 2015/1157 | bao, 2--5cm | 5.58 | 100.74 | 83.54 | 1.17 | 25.89 | 23.98 | -1.9 |
| 20 Feb 2015/1112 | bao, 10--13cm | 2.15 | 99.59 | 87.36 | 1.28 | 18.41 | 16.38 | -2.0 |
| 20 Feb 2015/1129 | bao, 20-23cm | 2.50 | 89.51 | 78.51 | 1.14 | 16.56 | 13.17 | -3.4 |
| 9 Mar 2015/1430 | ehs, 2--5cm | 16.477 | 142.333 | 127.741 | 1.67 | 21.96 | 28.4 | 6.4 |
| 20 Apr 2015/1500 | ehs,4--7cm | 8.237+8.260 | 81.960+60.946 | 70.854+52.124 | 1.60 | 30.00 | 29.47 | -0.5 |
| 20 Apr 2015/1500 | ehs, 9--12cm | 8.232+8.214 | 71.380+74.505 | 62.335+65.162 | 1.67 | 27.68 | 28.20 | 0.5 |
| 20 Apr 2015/1500 | ehs, 19–22cm (not completely full, by about 2mm?) | 8.265+2.139 | 96.082+29.133 | 84.192+25.476 | 1.49 (likely low) | 23.40 | 26.00 | 2.6 |
Note: Dry taken 23 Feb after air-drying in the lab for 3 days, then baking in the toaster oven for an hour. (The oven got rid of about another 1.5g in each sample.)
The results show all EC5s about 2% low (which could be due to coupling to the soil, just after installation).
Note2: 9 Mar sample processed as 2 aliquots (since scale range was limited). The sum of both aliquots is shown in the above table.
Note3: 20 Apr sample also processed as 2 aliquots. Both are shown above.
Note4: Tried to get a better depth match with 20 Apr samples, moving the 1cm ring to the top.
Note5: 20 Apr EC5 readings taken using minicom – see teardown comment.
Note6: assume that 9 Mar had a math error: 142.333, rather than 152.333???
tare = c(5.58, 2.15, 2.50, 16.477, 8.237+8.260, 8.232+8.214, 8.265+2.139)
wet = c(100.74, 99.59, 89.51, 142.333, 81.960+60.946, 71.380+74.505, 96.082+29.133)-tare
dry = c(83.54, 87.36, 78.51, 127.741, 70.854+52.124, 62.335+65.162, 84.192+25.476)-tare
vol = 3*pi*(5.31/2)^2
rho = dry/vol
moist = (100*(wet-dry)/vol) # density numerically equal to volume mixing ratio since rho_water = 1.
ec5 = c(23.98, 16.38, 13.17, 28.4, 29.47, 28.20, 26.00)
matplot(moist,ec5,xlim=c(0,40),ylim=c(0,40)); abline(0,1,lty=2)