LUE_YIELD_VPD {lue}

Light Use Efficiency Model to Estimate Crop Yield with Vapour Pressure Deficit

Description

LUE_YIELD_VPD() to estimate crop yield firstly by calculating the Absorbed Photosynthetically Active Radiation (APAR) and secondly the actual values of light use efficiency by including vapour pressure deficit of the crops Shi et al.(2007) <doi:10.2134/agronj2006.0260>.

Usage

LUE_YIELD_VPD(fpar_raster,par,tmin,tmax,tdew,
tmin_min,tmin_max,vpd_max, vpd_min,LUE_optimal)

Arguments

fpar_raster

fraction of photosynthetically active radiation (fpar) per day raster with .tif format

par

clear sky surface photosynthetically active radiation (par) per day raster with .nc file format.

tmin

Minimum temperature at 2 metres since previous post-processing per day raster with .nc file format.

tmax

Maximum temperature at 2 metres since previous post-processing per day raster with .nc file format.

tdew

Dewpoint temperature at 2 metres since previous post-processing per day raster with .nc file format.

tmin_min

minimum value of tmin used for the threshold

tmin_max

maximum value of tmin used for the threshold

vpd_max

maximum value of vapour pressure deficit used for the threshold

vpd_min

minimum value of vapour pressure deficit used for the threshold

LUE_optimal

optical lue value with respect to crop type for example wheat crop LUE_optimal is 3.0 (Djumaniyazova et al., 2010)

Format

A Biomass raster

Value

Yield raster

References

Djumaniyazova Y, Sommer R, Ibragimov N, Ruzimov J, Lamers J & Vlek P (2010) Simulating water use and N response of winter wheat in the irrigated floodplains of Northwest Uzbekistan. Field Crops Research 116, 239-251.

Shi Z, Ruecker G R,Mueller M, Conrad C, Ibragimov N, Lamers J P A, Martius C, Strunz G, Dech S & Vlek P L G (2007) Modeling of Cotton Yields in the Amu Darya River Floodplains of Uzbekistan Integrating Multitemporal Remote Sensing and Minimum Field Data. Agronomy Journal 99, 1317-1326.

Examples

## Not run: 
## load the data
data(fpar)
data(par1)
data(tmin)
data(tmax)
data(tdew)
LUE_YIELD_VPD(fpar,par1,tmin,tmax,tdew,-2,12,1.5,4,3)

## End(Not run)
library(raster)
fparr <- raster(nc=2, nr=2)
values(fparr)<-runif(ncell(fparr),min =0.2,max= 0.8)
par11<- brick(nc=2, nr=2, nl=2)
values(par11)<-runif(ncell(par11),min =169076.9,max= 924474.6)
tminn <- brick(nc=2, nr=2, nl=2)
values(tminn)<-runif(ncell(tminn),min = 278,max= 281)
tmaxx <- brick(nc=2, nr=2, nl=2)
values(tmaxx)<-runif(ncell(tmaxx),min = 278,max= 281)
tdeww <- brick(nc=2, nr=2, nl=2)
values(tdeww)<-runif(ncell(tdeww),min = 278,max= 281)
LUE_YIELD_VPD(fparr,par11,tminn,tmaxx,tdeww,-2,12,1.5,4,3)