Mean Normalized Usage (MNU)
GENERAL INFORMATION
DATA TITLE: Mean Normalized Usage (MNU) of Environmental Covariates for Cubist Soil Property Prediction Models
PROJECT TITLE: Digital soil mapping via machine learning of agronomic properties for the full soil profile at within-field resolution
DATA ABSTRACT: This dataset and code repository contain the results and scripts used to evaluate the relative importance of environmental covariates across 126 machine learning models predicting a suite of soil agronomic properties for the full soil profile (18 soil properties × 7 depth intervals). Covariate importance is normalized to account for usage frequency of covariate predictors as model rules and linear model coefficients across depth class, covariate type, and analysis scale.
ASSOCIATED PUBLICATIONS
Bohn, M.P., B.A. Miller. 2025. Digital soil mapping via machine learning of agronomic properties for the full soil profile at within-field resolution. Agronomy Journal. (In Press)
COLLECTION INFORMATION
Time period(s): 2019 Location(s): Sustainable Advanced Bioeconomy Research Farm, Ames, IA, USA
CODEBOOK
Number Of Variables/Columns: 14 baseline + 6 generated = 20 total Number Of Cases/Rows: 10,108 Missing Data Codes: NA
Columns in the Base Data
Column |
Description |
|---|---|
model_conditions |
Percent usage as model rule in decision tree |
model_usage |
Percent usage in multiple linear regression as coefficient |
covariate |
Covariate name including analysis scale or year |
Deriv |
Remote-sensed derivative type (Terrain or Imagery) |
type1 |
Specific derivative classification |
type2 |
Generalized derivative classification |
stat |
Statistical aggregation method |
year |
Year of remote-sensed data source |
prop |
Soil property model and depth interval |
soil |
Soil property name |
depth_int |
Depth interval (cm) |
depth |
Cleaned depth interval name (cm) |
top_depth |
Top depth of depth interval (cm) |
bot_depth |
Bottom depth of depth interval (cm) |
Columns Produced by mean_normalized_usage()
Column |
Description |
|---|---|
analysis.scale |
Analysis scale of covariate (m) |
rel_scale |
Relative verbal scale classification of analysis scale |
depth_class |
Verbal scale classification of depth interval |
total_usage |
Sum of model_conditions and model_usage |
total_covs |
Total number of covariates in the soil x depth model |
total_usage_scaled |
Min-max normalized value of total_usage |
total_covs_scaled |
Min-max normalized value of total_covs |
normalized_usage |
Product of total_usage_scaled and total_covs_scaled |
mean_normalized_usage |
Group mean of normalized_usage |
Soil Properties Modeled
Property |
Description |
Units |
|---|---|---|
Ca |
Calcium cation |
mg kg⁻¹ |
CCE |
Calcium Carbonate Equivalent |
% |
CEC |
Cation Exchange Capacity |
cmolc kg⁻¹ |
cf |
Coarse Fragments |
% |
clay |
Clay Fraction |
% |
EC |
Electrical Conductivity |
dS m⁻¹ |
K |
Potassium cation |
mg kg⁻¹ |
Mg |
Magnesium cation |
mg kg⁻¹ |
Na |
Sodium cation |
mg kg⁻¹ |
Olsen P |
Olsen Test Phosphorus |
mg kg⁻¹ |
pH |
pH (1:1 soil water suspension) |
— |
sand |
Sand Fraction |
% |
silt |
Silt Fraction |
% |
Cstock |
Soil Organic Carbon Stock |
g cm⁻² |
TOC |
Total Organic Carbon |
% |
Total N |
Total Nitrogen |
% |
Bray P |
Bray Test Phosphorus |
mg kg⁻¹ |
buf_pH |
Buffered pH |
— |
Covariate Metadata
Covariate |
Description |
|---|---|
CA |
Catchment area |
crosc |
Cross-sectional curvature |
CS |
Catchment slope |
HDCN_strahl3_d |
Horizontal distance to channel network (Strahler 3) |
IR |
Infrared band |
MCA |
Modified catchment area |
NAIP |
National Agriculture Imagery Program |
nnes |
Northness |
plc |
Plan curvature |
prc |
Profile curvature |
rel |
Relative elevation |
slp |
Slope gradient |
SWI |
SAGA wetness index |
tpi |
Topographic position index |
wnes |
Westness |