### 2.26.2.2. Crop plant functional types[¶](#crop-plant-functional-types "Permalink to this headline")

To allow crops to coexist with natural vegetation in a grid cell, the vegetated land unit is separated into a naturally vegetated land unit and a managed crop land unit. Unlike the plant functional types (PFTs) in the naturally vegetated land unit, the managed crop PFTs in the managed crop land unit do not share soil columns and thus permit for differences in the land management between crops. Each crop type has a rainfed and an irrigated PFT that are on independent soil columns. Crop grid cell coverage is assigned from satellite data (similar to all natural PFTs), and the managed crop type proportions within the crop area is based on the dataset created by [Portmann et al. (2010)](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#portmannetal2010) for present day. New in CLM5, crop area is extrapolated through time using the dataset provided by Land Use Model Intercomparison Project (LUMIP), which is part of CMIP6 Land use timeseries ([Lawrence et al. 2016](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#lawrenceetal2016)). For more details about how crop distributions are determined, see Chapter [2.27](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/Transient_Landcover/CLM50_Tech_Note_Transient_Landcover.html#rst-transient-landcover-change).

CLM5 includes ten actively managed crop types (temperate soybean, tropical soybean, temperate corn, tropical corn, spring wheat, cotton, rice, sugarcane, miscanthus, and switchgrass) that are chosen based on the availability of corresponding algorithms in AgroIBIS and as developed by [Badger and Dirmeyer (2015)](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#badgeranddirmeyer2015) and described by [Levis et al. (2016)](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#levisetal2016), or from available observations as described by [Cheng et al. (2019)](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#chengetal2019). The representations of sugarcane, rice, cotton, tropical corn, and tropical soy were new in CLM5; miscanthus and switchgrass were added after the CLM5 release. Sugarcane and tropical corn are both C4 plants and are therefore represented using the temperate corn functional form. Tropical soybean uses the temperate soybean functional form, while rice and cotton use the wheat functional form. In tropical regions, parameter values were developed for the Amazon Basin, and planting date window is shifted by six months relative to the Northern Hemisphere. Plantation areas of bioenergy crops are projected to expand throughout the 21st century as a major energy source to replace fossil fuels and mitigate climate change. Miscanthus and switchgrass are perennial bioenergy crops and have quite different physiological traits and land management practices than annual crops, such as longer growing seasons, higher productivity, and lower demands for nutrients and water. About 70% of biofuel aboveground biomass (leaf & livestem) is removed at harvest. Parameter values were developed by using observation data collected at the University of Illinois Energy Farm located in Central Midwestern United States ([Cheng et al., 2019](https://escomp.github.io/ctsm-docs/versions/master/html/tech_note/References/CLM50_Tech_Note_References.html#chengetal2019)).

In addition, CLM’s default list of plant functional types (PFTs) includes an irrigated and unirrigated unmanaged C3 crop ([Table 2.26.1](#table-crop-plant-functional-types)) treated as a second C3 grass. The unmanaged C3 crop is only used when the crop model is not active and has grid cell coverage assigned from satellite data, and the unmanaged C3 irrigated crop type is currently not used since irrigation requires the crop model to be active. The default list of PFTs also includes twenty-one inactive crop PFTs that do not yet have associated parameters required for active management. Each of the inactive crop types is simulated using the parameters of the spatially closest associated crop type that is most similar to the functional type (e.g., C3 or C4), which is required to maintain similar phenological parameters based on temperature thresholds. Information detailing which parameters are used for each crop type is included in [Table 2.26.1](#table-crop-plant-functional-types). It should be noted that PFT-level history output merges all crop types into the actively managed crop type, so analysis of crop-specific output will require use of the land surface dataset to remap the yields of each actively and inactively managed crop type. Otherwise, the actively managed crop type will include yields for that crop type and all inactively managed crop types that are using the same parameter set.

Table 2.26.1 Crop plant functional types (PFTs) included in CLM5BGCCROP.[¶](#id20 "Permalink to this table")    
| IVT
 | Plant function types (PFTs)

 | Management Class

 | Crop Parameters Used

 |
| --- | --- | --- | --- |
| 15

 | c3 unmanaged rainfed crop

 | none

 | not applicable

 |
| 16

 | c3 unmanaged irrigated crop

 | none

 | not applicable

 |
| 17

 | rainfed temperate corn

 | active

 | rainfed temperate corn

 |
| 18

 | irrigated temperate corn

 | active

 | irrigated temperate corn

 |
| 19

 | rainfed spring wheat

 | active

 | rainfed spring wheat

 |
| 20

 | irrigated spring wheat

 | active

 | irrigated spring wheat

 |
| 21

 | rainfed winter wheat

 | inactive

 | rainfed spring wheat

 |
| 22

 | irrigated winter wheat

 | inactive

 | irrigated spring wheat

 |
| 23

 | rainfed temperate soybean

 | active

 | rainfed temperate soybean

 |
| 24

 | irrigated temperate soybean

 | active

 | irrigated temperate soybean

 |
| 25

 | rainfed barley

 | inactive

 | rainfed spring wheat

 |
| 26

 | irrigated barley

 | inactive

 | irrigated spring wheat

 |
| 27

 | rainfed winter barley

 | inactive

 | rainfed spring wheat

 |
| 28

 | irrigated winter barley

 | inactive

 | irrigated spring wheat

 |
| 29

 | rainfed rye

 | inactive

 | rainfed spring wheat

 |
| 30

 | irrigated rye

 | inactive

 | irrigated spring wheat

 |
| 31

 | rainfed winter rye

 | inactive

 | rainfed spring wheat

 |
| 32

 | irrigated winter rye

 | inactive

 | irrigated spring wheat

 |
| 33

 | rainfed cassava

 | inactive

 | rainfed rice

 |
| 34

 | irrigated cassava

 | inactive

 | irrigated rice

 |
| 35

 | rainfed citrus

 | inactive

 | rainfed spring wheat

 |
| 36

 | irrigated citrus

 | inactive

 | irrigated spring wheat

 |
| 37

 | rainfed cocoa

 | inactive

 | rainfed rice

 |
| 38

 | irrigated cocoa

 | inactive

 | irrigated rice

 |
| 39

 | rainfed coffee

 | inactive

 | rainfed rice

 |
| 40

 | irrigated coffee

 | inactive

 | irrigated rice

 |
| 41

 | rainfed cotton

 | active

 | rainfed cotton

 |
| 42

 | irrigated cotton

 | active

 | irrigated cotton

 |
| 43

 | rainfed datepalm

 | inactive

 | rainfed cotton

 |
| 44

 | irrigated datepalm

 | inactive

 | irrigated cotton

 |
| 45

 | rainfed foddergrass

 | inactive

 | rainfed spring wheat

 |
| 46

 | irrigated foddergrass

 | inactive

 | irrigated spring wheat

 |
| 47

 | rainfed grapes

 | inactive

 | rainfed spring wheat

 |
| 48

 | irrigated grapes

 | inactive

 | irrigated spring wheat

 |
| 49

 | rainfed groundnuts

 | inactive

 | rainfed rice

 |
| 50

 | irrigated groundnuts

 | inactive

 | irrigated rice

 |
| 51

 | rainfed millet

 | inactive

 | rainfed tropical corn

 |
| 52

 | irrigated millet

 | inactive

 | irrigated tropical corn

 |
| 53

 | rainfed oilpalm

 | inactive

 | rainfed rice

 |
| 54

 | irrigated oilpalm

 | inactive

 | irrigated rice

 |
| 55

 | rainfed potatoes

 | inactive

 | rainfed spring wheat

 |
| 56

 | irrigated potatoes

 | inactive

 | irrigated spring wheat

 |
| 57

 | rainfed pulses

 | inactive

 | rainfed spring wheat

 |
| 58

 | irrigated pulses

 | inactive

 | irrigated spring wheat

 |
| 59

 | rainfed rapeseed

 | inactive

 | rainfed spring wheat

 |
| 60

 | irrigated rapeseed

 | inactive

 | irrigated spring wheat

 |
| 61

 | rainfed rice

 | active

 | rainfed rice

 |
| 62

 | irrigated rice

 | active

 | irrigated rice

 |
| 63

 | rainfed sorghum

 | inactive

 | rainfed tropical corn

 |
| 64

 | irrigated sorghum

 | inactive

 | irrigated tropical corn

 |
| 65

 | rainfed sugarbeet

 | inactive

 | rainfed spring wheat

 |
| 66

 | irrigated sugarbeet

 | inactive

 | irrigated spring wheat

 |
| 67

 | rainfed sugarcane

 | active

 | rainfed sugarcane

 |
| 68

 | irrigated sugarcane

 | active

 | irrigated sugarcane

 |
| 69

 | rainfed sunflower

 | inactive

 | rainfed spring wheat

 |
| 70

 | irrigated sunflower

 | inactive

 | irrigated spring wheat

 |
| 71

 | rainfed miscanthus

 | active

 | rainfed miscanthus

 |
| 72

 | irrigated miscanthus

 | active

 | irrigated miscanthus

 |
| 73

 | rainfed switchgrass

 | active

 | rainfed switchgrass

 |
| 74

 | irrigated switchgrass

 | active

 | irrigated switchgrass

 |
| 75

 | rainfed tropical corn

 | active

 | rainfed tropical corn

 |
| 76

 | irrigated tropical corn

 | active

 | irrigated tropical corn

 |
| 77

 | rainfed tropical soybean

 | active

 | rainfed tropical soybean

 |
| 78

 | irrigated tropical soybean

 | active

 | irrigated tropical soybean

 |

