| Available_K | Available potassium (K) in soil |
| Available_P | Available phosphorus (P) in soil determined by ascorbic acid blue colour method |
| df_Available_K | Example Data Frame for available potassium (K) in soils |
| df_Available_P | Example Data Frame for available phosphorus (P) in soils |
| df_DTPA_Micro | Example Data Frame for available micronutrient cations in soils |
| df_Minearl_N | Example Data Frame for mineral nitrogen (N) in soil |
| df_N_Boric | Example Data Frame for total nitrogen (N) and available or mineralizable N in soil |
| df_N_Sulphuric | Example Data Frame for total nitrogen (N) in soil |
| df_Std_Curve | Example Data Frame for element concentration from standard curve |
| df_WBC | Example Data Frame for oxidizable organic carbon (C) or Walkley-Black C in soil |
| DTPA_Micro | Available micronutrient cations in soil |
| Mineral_N | Mineral N i.e., summation of ammonium-N and nitrate-N in soil |
| N_Boric | Total, or Mineralizable Nitrogen using boric acid for ammonia absorption |
| N_Sulphuric | Total Nitrogen (N) using sulphuric acid for ammonia absorption |
| Std_Curve | Elemental concentration in solution from absorbance or emission values |
| WBC | Oxidizable organic carbon (C) or Walkley-Black C in soil |