Overyield’s Suitability Layer provide users with a better understanding of their land’s productive potential by way of various crop, soil, and climate heat-maps. The following article describes the underlying algorithms for these maps while citing each crop map’s data sources.
Basics
In generating Suitability maps for the continental US, Overyield cross-references a given crop’s environmental preferences with a selected parcel’s soil and climate characteristics, obtained through USGS and NRCS datasets.
These datasets indicate a parcel’s pH, depth to restrictive layer (i.e. bedrock), depth to the water table, flooding frequency, slope percentage, drainage class, hydric rating, and soil surface texture.
Calculations
For each soil and climate parameter, potential values realizable across the continental US are pre-defined, given as ranges. Take, for example, the table below, which lists potential slope values within our algorithm. These values run the gamut from 0-3% to 100-1000%.
Parameter | Low | High | Score | Score Notes |
Slope | 0 | 3 | 3 | Ok |
Slope | 3 | 8 | 5 | Prefers slight slope for drainage |
Slope | 8 | 25 | 3 | Ok |
Slope | 25 | 50 | 0 | Likely unsuitable |
Slope | 50 | 60 | -100 | Unsuitable for equipment |
Slope | 60 | 70 | -100 |
|
Slope | 70 | 80 | -100 |
|
Slope | 80 | 90 | -100 |
|
Slope | 90 | 100 | -100 |
|
Slope | 100 | 1000 | -100 |
|
For each parameter, a crop’s suitability is then determined by assigning an acceptability score to individual ranges, depending on the crop’s preferences. In the given example, a crop preferring a slight slope achieved a score of 5 for the 3-8% range, in contrast to scores of 3, 0, and an arbitrary negative number — in this case -100 — for slopes that are less suitable or unsuitable for that crop.
A color classification system is then applied to these scores, with high suitability scores represented by deep green, and the low suitability scores represented by red.
Three additional classifications, represented by varying shades of grey, are unsuitable due to land use and/or environmental factors.
Data sources
Parcel Data
American Elderberry
Chinese Chestnut
American Hazelnut
Black Locust
Suitability Maps in Testing
The following maps are in progress, their approval pending validation:
Common Name | Latin Genus | Latin Species |
Apple | Malus | domestica |
Aronia | Aronia | melanocarpa |
Bitternut Hickory | Carya | cordiformis |
Blackcurrant | Ribes | Nigrum |
European Elderberry | Sambucus | nigra |
European Hazelnut | Corylus | avellana |
Fodder Mulberry (same as Mulberry fruit) | Morus | alba |
Honey Locust | Gleditsia | triacanthos |
Hybrid Poplar | Populus | deltoides/ nigra |
Paulownia | Paulownia | spp |
Peach | Prunus | persica |
Pecan | Carya | illinoinensis |
Saskatoon | Amelanchier | alnifolia |
Silver Maple | Acer | saccharinum |
Sycamore | Platanus | spp |
Willow (SX-61) | Salix | spp |