Table 1 Description of the variables.
From: Late-season corn stalk nitrate measurements across the US Midwest from 2006 to 2018
Variable | Description | Missing Values | Levels/Range | Additional Information | Example |
|---|---|---|---|---|---|
Field_ID | Field ID | 0 | Levels: 10,675 | Unique for each field | GSS2010OHMM015 |
Sample_Number | Sample number |  | Range: 1–3 |  | 1 |
Year | Year | 0 | Range: 2006–2018 |  | 2006 |
State | State | 0 | Levels: 6 | IA, IL, IN, MI, MN, OH | IA |
County | County name | 15 | Levels: 172 | Â | Allen |
County_centroid_latitude | County of the field centroid latitude | 144 | Range: 38.0–47.1 |  | 41.64752 |
County_centroid_longitude | County of the field centroid longitude | 144 | Range: −96.2 - −83.6 |  | −94.73380 |
Previous_crop | Previous crop | 366 | Levels: 18 | Â | Soybean |
Manure_type | Manure animal source | 0 | Levels: 7 | No manure and 7 animals | Swine Manure |
Manure_application | Was manure applied | 0 | Levels: 2 | Yes, No | Yes |
N_fertilizer_form | Nitrogen fertilizer form | 0 | Levels: 16 | Â | Urea |
N_fertilizer_form_simplified | Simplified N Form | 0 | Levels: 5 | Â | UAN |
N_application_timing | Nitrogen fertilizer timing | 1905 | Levels: 8 | Â | Spring |
N_application_timing_simplified | Nitrogen fertilizer timing | 1905 | Levels: 5 | Â | Fall |
N_management | Combined Timing and N_form | 0 | Levels: 44 | Â | Fall_Swine Manure |
N_management_simplified | Combined Timing_simplified and N_form_simplified | 0 | Levels: 17 | Â | Fall_Manure |
Tillage_use | Whether tillage was done or not | 726 | Levels: 2 | Â | no-till |
Total_N_rate_lbac | Total N rate | 0 | Range: 4–780 (lb/ac) |  | 117 |
Total_N_rate_kgha | Total N rate | 0 | Range: 4.5–873.6 (kg/ha) |  | 131.04 |
Stalk_nitrate_CSNT | Stalk Nitrate-N | 0 | Range: 1–36,700 (ppm) |  | 343 |
GM_ppm | Stalk nitrate geometric mean of each field | 0 | Range: 1–16,326 (ppm) |  | 348.8 |
GM_4_category | 4 categories of GM | 0 | Levels: 4 | Deficient, Marginal, Optimal, Excessive | Marginal |
GM_2_category | 2 categories of GM | 0 | Levels: 2 | Deficient, Sufficient | Sufficient |
