| RecType | | Physical quantity | Record type |
| Plot_2017 | | Nominal | Plot designation in 2017, after irrigation lines were shifted |
| initial_date | | Date/time | date initial soil cores were taken and incubated cores were buried |
| DOY | | Physical quantity | Day of year |
| Current | | Nominal | Treatment in 2017, after irrigation lines were shifted. |
| Position | | Nominal | Landscape position in the upland or lowland |
| Replicate | | Nominal | Irrigation line: (A) started in 1991, (B) started in 1993 |
| Replicate_ed | | Nominal | Irrigation lines as in 'Replicate', but divided into uplands and lowlands to yield spatial 'blocks' |
| Transect_1993 | | Nominal | Previous treatment (1991-2016)
|
| Plot_1992 | | Nominal | Plot designations in 1992, while second irrigation line was being added. These plot designations are not typically used
|
| nh4ppm_soil | | Physical quantity | NH4-N concentration in soil
|
| no3ppm_soil | | Physical quantity | NO3-N concentration in soil |
