MatchForage

Suitability patterns for forage species are caused by different factors in different locations. Low winter temperatures limit the northern range of many species, while low precipitation limits the western range of species in the semi-arid west. Low summer temperatures limit the range of species with increasing elevation while high summer temperatures limit the range in the desert southwest and hot and humid southeast. Soil characteristics (pH, drainage, and salinity) also limit the suitability zones of forage species. However, soil amendments (liming and drainage tiles) can alleviate many of these limitations. Thus, NRCS Soil Survey data should be informed and revised by management mitigations.

Nine maps have been developed; 1) 30-year long-term July maximum temperature 2), 3) 30-year long-term annual precipitation, 4) soil pH, 5) soil drainage, 6) soil salinity, 7) combined climate factors, 8) combined soil factors, and 9) combined climate and soil factors.

Suitability patterns for forage species are caused by different factors in different locations. Low winter temperatures limit the northern range of many species, while low precipitation limits the western range of species in the semi-arid west. Low summer temperatures limit the range of species with increasing elevation while high summer temperatures limit the range in the desert southwest and hot and humid southeast. Soil characteristics (pH, drainage, and salinity) also limit the suitability zones of forage species. However, soil amendments (liming and drainage tiles) can alleviate many of these limitations. Thus, NRCS Soil Survey data should be informed and revised by management mitigations.

Nine maps have been developed; 1) 30-year long-term July maximum temperature 2), 3) 30-year long-term annual precipitation, 4) soil pH, 5) soil drainage, 6) soil salinity, 7) combined climate factors, 8) combined soil factors, and 9) combined climate and soil factors.

Historically, maps have been drawn based on primary use areas, showing broad geographic areas, e.g. Compendium of Common Forages maps within Forages: An Introduction to Grassland Agriculture, 7th ed. (2018), John Wiley & Sons, Inc.

More highly detailed maps, based on quantitative climatic and soil factor tolerances and using GIS spatial grids, provide information on where species are suitable for a variety of intended uses.

The following collection of maps were developed by a group of Oregon State University scientists, using the PRISM-generated collection of climate factor grids and the NRCS soil characteristics database.

 Suitability curves were developed for each clover species for three climate variables (average annual precipitation, average July maximum temperature, and average annual extreme low temperature) and three soil variables (drainage class, pH, and salinity). For each variable and each species, the curves were fit using estimated yield data across the full range of values for the given variable.  

The coefficients for the model equations were applied to spatial data layers representing each climate and soil variable, resulting in spatial outputs of percent yield for each of the clover species and each climate and soil variable. The percent yield layers were then classified into four suitability classes, as follows: 

100%-75% - Suitable
75%-50%  - Moderately suitable
50%-25%  - Marginally suitable
25-0%    - Not suitable

Finally, three "hybrid" suitability layers were produced for each clover species based on combinations of 1) the three climate variables, 2) the three soil variables, and 3) all six climate and soil variables together.  These combined suitability layers were created by selecting for each location the lowest suitability value of the included variables, with the idea that the overall suitability for a species will be limited by the most restrictive factor. 

 QUANTITATIVE TOLERANCES GIS-BASED MAPS

The contiguous USA

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature clarkatlaspagesbalansa_tmin.png	pH clarkatlaspagesbalansa_ph.png	All climate and soil factors (most limiting)
Maximum Temperature clarkatlaspagesbalansa_tmax.png	Drainage clarkatlaspagesbalansa_dc.png	All soil factors (most limiting)
Precipitation clarkatlaspagesbalansa_precip.png	Salinity clarkatlaspagesbalansa_sal.png	All climate factors (Most limiting) clarkatlaspagesbalansa_climate.png

Historically, maps have been drawn based on primary use areas, showing broad geographic areas, e.g. Compendium of Common Forages maps within Forages: An Introduction to Grassland Agriculture, 7th ed. (2018), John Wiley & Sons, Inc.

crimson_clover_forages_map.jpg

(Crimson clover adaptation and use map.)

(Crimson clover SARE cover crop map. Source: Managing Cover Crops Profitably, 3rd Ed., Sustainable Agriculture Research & Education.)

More highly detailed maps, based on quantitative climatic and soil factor tolerances and using GIS spatial grids, provide information on where species are suitable for a variety of intended uses.

The following collection of maps were developed by a group of Oregon State University scientists, using the PRISM-generated collection of climate factor grids and the NRCS soil characteristics database.

Quantitative Tolerances GIS-based Maps

The contiguous USA

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature crimson_tmin_us.jpg	pH crimson_ph_us.jpg	Climate and Soil crimson_all_us.jpg
Maximum Temperature crimson_tmax_us.jpg	Drainage crimson_dc_us.jpg	All Soil crimson_soil_us.jpg
Precipitation crimson_precip_us.jpg	Salinity crimson_sal_us.jpg	All Climate crimson_climate_us.jpg

State Maps

Alaska

Climate Factor	Soil Factors	Combined Factors
Minimum Temperature crimson_tmin_ak.jpg	pH crimson_ph_ak.jpg	Climate and Soil crimson_all_ak.jpg
Maximum Temperature crimson_tmax_ak.jpg	Drainage crimson_dc_ak.jpg	All Soil crimson_soil_ak.jpg
Precipitation crimson_precip_ak.jpg	Salinity crimson_sal_ak.jpg	All Climate crimson_climate_ak.jpg

Hawaii

Climate Factor	Soil Factors	Combined Factors
Minimum Temperature crimson_tmin_hi.jpg	pH crimson_ph_hi.jpg	Climate and Soil crimson_all_hi.jpg
Maximum Temperature crimson_tmax_hi.jpg	Drainage crimson_dc_hi.jpg	All Soil crimson_soil_hi.jpg
Precipitation crimson_precip_hi.jpg	Salinity crimson_sal_hi.jpg	All Climate crimson_climate_hi.jpg

Oregon

Climate Factor	Soil Factors	Combined Factors
Minimum Temperature crismon_tmin.jpg	pH crismon_ph.jpg	Climate and Soil crismon_all.jpg
Maximum Temperature crismon_tmax.jpg	Drainage crismon_dc.jpg	All Soil crismon_soil.jpg
Precipitation crismon_precip.jpg	Salinity crismon_sal.jpg	All Climate crismon_climate.jpg

The following collection of maps were developed by a group of Oregon State University scientists, using the PRISM-generated collection of climate factor grids and the NRCS soil characteristics database. The procedure used to produce these suitability maps is described below.

Suitability curves were developed for each clover species for three climate variables (average annual precipitation, average July maximum temperature, and average annual extreme low temperature) and three soil variables (drainage class, pH, and salinity). For each variable and each species, the curves were fit using estimated yield data across the full range of values for the given variable.  

The coefficients for the model equations were applied to spatial data layers representing each climate and soil variable, resulting in spatial outputs of percent yield for each of the clover species and each climate and soil variable. The percent yield layers were then classified into four suitability classes, as follows: 

100%-75% - Suitable
75%-50%  - Moderately suitable
50%-25%  - Marginally suitable
25-0%    - Not suitable

Finally, three "hybrid" suitability layers were produced for each clover species based on combinations of 1) the three climate variables, 2) the three soil variables, and 3) all six climate and soil variables together.  These combined suitability layers were created by selecting for each location the lowest suitability value of the included variables, with the idea that the overall suitability for a species will be limited by the most restrictive factor. 

 QUANTITATIVE TOLERANCES GIS-BASED MAPS

The contiguous USA

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature clarkatlaspagespersian_tmin.png	pH clarkatlaspagespersian_ph.png	All climate and soil factors (most limiting)
Maximum Temperature clarkatlaspagespersian_tmax.png	Drainage clarkatlaspagespersian_dc.png	All soil factors (most limiting)
Precipitation clarkatlaspagespersian_precip.png	Salinity clarkatlaspagespersian_sal.png	All climate factors (Most limiting) clarkatlaspagespersian_climate.png

The following collection of maps were developed by a group of Oregon State University scientists, using the PRISM-generated collection of climate factor grids and the NRCS soil characteristics database. The procedure used to produce these suitability maps is described below.

Suitability curves were developed for each clover species for three climate variables (average annual precipitation, average July maximum temperature, and average annual extreme low temperature) and three soil variables (drainage class, pH, and salinity). For each variable and each species, the curves were fit using estimated yield data across the full range of values for the given variable.  

The coefficients for the model equations were applied to spatial data layers representing each climate and soil variable, resulting in spatial outputs of percent yield for each of the clover species and each climate and soil variable. The percent yield layers were then classified into four suitability classes, as follows: 

100%-75% - Suitable
75%-50%  - Moderately suitable
50%-25%  - Marginally suitable
25-0%    - Not suitable

Finally, three "hybrid" suitability layers were produced for each clover species based on combinations of 1) the three climate variables, 2) the three soil variables, and 3) all six climate and soil variables together.  These combined suitability layers were created by selecting for each location the lowest suitability value of the included variables, with the idea that the overall suitability for a species will be limited by the most restrictive factor. 

QUANTITATIVE TOLERANCES GIS-BASED MAPS

The contiguous USA

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature clarkatlaspagesrose_tmin.png	pH clarkatlaspagesrose_ph.png	All climate and soil factors (most limiting)
Maximum Temperature clarkatlaspagesrose_tmax.png	Drainage clarkatlaspagesrose_dc.png	All soil factors (most limiting)
Precipitation clarkatlaspagesrose_precip.png	Salinity clarkatlaspagesrose_sal.png	All climate factors (Most limiting) rose_climate.png

Historically, maps have been drawn based on primary use areas, showing broad geographic areas, e.g. Compendium of Common Forages maps within Forages: An Introduction to Grassland Agriculture, 7th ed. (2018), John Wiley & Sons, Inc.

(Subterranean Clover Adaptation & Use Map.)

sub_clover_sare_cover_crops_map.jpg

(SARE Managing Cover Crops Map. Source: Managing Cover Crops Profitably, 3rd Ed., Sustainable Agriculture Research & Education.)

More highly detailed maps, based on quantitative climatic and soil factor tolerances and using GIS spatial grids, provide information on where species are suitable for a variety of intended uses.

The following collection of maps were developed by a group of Oregon State University scientists, using the PRISM-generated collection of climate factor grids and the NRCS soil characteristics database.

Quantitative Tolerances GIS Maps

The contiguous USA

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature Wet subterranean_wet_tmin.jpg	pH Wet subterranean_wet_ph.jpg	Climate and Soil Wet subterranean_wet_all.jpg
Minimum Temperature Dry subterranean_dry_tmin.jpg	pH Dry subterranean_dry_ph.jpg	Climate and Soil Dry subterranean_dry_all.jpg
Maximum Temperature Wet subterranean_wet_tmax.jpg	Drainage Wet subterranean_wet_dc.jpg	All Soil subterranean_wet_soil.jpg
Precipitation Wet subterranean_wet_precip.jpg	Salinity Wet subterranean_wet_sal.jpg	All Climate Wet subterranean_wet_climate.jpg
Precipitation Dry subterranean_dry_precip.jpg	Salinity Dry subterranean_dry_sal.jpg	All Climate Dry subterranean_dry_climate.jpg

Map designations of wet and dry refer to different precipitation requirements for current use areas (40-60 inch rainfall zones, designated wet) and potential use areas (16-26 inch rainfall zones, designated dry). 

State Maps

Alaska

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature Wet subterranean_wet_tmin_ak.jpg	pH Wet subterranean_wet_ph_ak.jpg	Climate and Soil Wet subterranean_wet_all_ak.jpg
Minimum Temperature Dry subterranean_tmin_ak.jpg	pH Dry subterranean_dry_ph_ak.jpg	Climate and Soil Dry subterranean_dry_all_ak.jpg
Maximum Temperature Wet subterranean_wet_tmax_ak.jpg	Drainage Wet subterranean_wet_dc_ak.jpg	All Soil Wet subterranean_wet_soil_ak.jpg
Precipitation Wet subterranean_wet_precip.jpg	Salinity Wet subterranean_wet_sal_ak.jpg	All Climate Wet subterranean_wet_climate_ak.jpg
Precipitation Dry subterranean_dry_precip_ak.jpg	Salinity Dry subterranean_dry_sal_ak.jpg	All Climate Dry subterranean_dry_climate_ak.jpg

Hawaii

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature Wet subterranean_wet_tmin.jpg	pH Wet subterranean_wet_ph.jpg	Climate and Soil Wet subterranean_wet_all.jpg
Minimum Temperature Dry subterranean_dry_tmin.jpg	pH Dry subterranean_dry_ph.jpg	Climate and Soil Dry subterranean_dry_all.jpg
Maximum Temperature Wet subterranean_wet_tmax.jpg	Drainage Wet subterranean_wet_dc.jpg	All Soil Wet subterranean_wet_soil.jpg
Precipitation Wet subterranean_wet_precip.jpg	Salinity Wet subterranean_wet_sal.jpg	All Climate Wet subterranean_wet_all.jpg
Precipitation Dry subterranean_dry_precip.jpg	Salinity Dry subterranean_dry_sal.jpg	All Climate Dry subterranean_dry_climate.jpg

Oregon

Climate Factors	Soil Factors	Combined Factors
Minimum Temperature Wet subterranean_wet_tmin_or.jpg	pH Wet subterranean_wet_ph_or.jpg	Climate and Soil Wet subterranean_wet_all_or.jpg
Minimum Temperature Dry subterranean_dry_tmin_or.jpg	pH Dry subterranean_dry_ph_or.jpg	Climate and Soil Dry subterranean_dry_all_or.jpg
Maximum Temperature Wet subterranean_wet_tmax_or.jpg	Drainage Wet subterranean_wet_dc_or.jpg	All Soil Wet subterranean_wet_soil_or.jpg
Precipitation Wet subterranean_wet_precip_or.jpg	Salinity Wet subterranean_wet_sal_or.jpg	All Climate Wet subterranean_wet_climate_or.jpg
Precipitation Dry subterranean_dry_precip_or.jpg	Salinity Dry subterranean_dry_sal_or.jpg	All Climate Dry subterranean_dry_climate_or.jpg