| RecType | | Physical quantity | Record type |
| RecYear | | Physical quantity | Year of sample |
| RecMonth | | Physical quantity | Month of sample |
| RecDay | | Physical quantity | Day of sample |
| Plot_2017 | | Nominal | Plot designation in 2017, after irrigation lines were shifted |
| DOY | | Physical quantity | Day of year |
| Position | | Nominal | Landscape position in the upland or lowland |
| Replicate | | Nominal | Irrigation line: (A) started in 1991, (B) started in 1993 |
| Plot_1992 | | Nominal | Plot designations in 1992, while second irrigation line was being added. These plot designations are not typically used
|
| Replicate_ed | | Nominal | Irrigation lines as in 'Replicate', but divided into uplands and lowlands to yield spatial 'blocks' |
| mbc_ppm | | Physical quantity | Soil microbial biomass C (ppm) (0-10 cm depth) measured on a TOC analyzer using chloroform fumigation extraction
|
| mbn_ppm | | Physical quantity | Soil microbial biomass N (ppm) (0-10 cm depth) measured using chloroform fumigation extraction, followed by persulfate digestion, and finally analysis for NO3-N on an Autoanalyzer |
| cn_ratio | | Physical quantity | mbc_ppm / mbn_ppm
|
