| RecType | | Physical quantity | Record type |
| RecYear | | Physical quantity | Year of record |
| Plot_2017 | | Nominal | Plot designation in 2017, after irrigation lines were shifted |
| PercentN | | Physical quantity | Percent N by mass of soil 0-10 cm. |
| PercentC | | Physical quantity | Percent C by mass of soil 0-10 cm. |
| Current | | Nominal | Treatment in 2017, after irrigation lines were shifted. |
| 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_1993 | | Nominal | Plot designation 1991-2017, before irrigation lines were shifted. Plots that are currently in the reduced (R) treatment did not have plot numbers during this time
|
| Plot_1992 | | Nominal | Plot designations in 1992, while second irrigation line was being added. These plot designations are not typically used.
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