lue (version 0.2.1)

LUE_YIELD: Light Use Efficiency Model to Estimate Crop Yield

Description

Contains LUE_YIELD() to estimate aboveground biomass firstly by calculating the Absorbed Photosynthetically Active Radiation (APAR) and secondly the actual values of light use efficiency Shi et al.(2007) <doi:10.2134/agronj2006.0260>.

Usage

LUE_YIELD(fpar_raster,par,tmin,tmin_min,tmin_max,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.

tmin_min

minimum value of tmin used for the threshold

tmin_max

maximum value of tmin 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)

Value

Yield raster

Format

A Biomass 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)
LUE_YIELD(fpar,par1,tmin,-2,12,3)
# }
# 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)
LUE_YIELD(fparr,par11,tminn,-2,12,3)
# }