ApsimSoil-SSURGO

This repo contains R code for downloading soils data from SSURGO database and converting it into APSIM format.

Code here relies heavily on the FedData package. APSIM parameter set estimation follows the approach described by Archontoulis et al. (2014, Agron. J. 106(3):1025-1040).

downloadSSURGO: (down)load spatial data for a field extent and return soil profiles with values for APSIM

Before using this function, make sure you have installed the following packages:

install.packages(c("FedData","raster","tidyverse","ggthemes","maptools","maps","XML","Hmisc","lubridate")

You will need to define the soil layer structure using the soilLayer_breaks arguement. Latitudinal extent of the area of interest is defined in the north and south arguements. Longitudinal extent of the area of interest is defined in the east and west arguements.

source("_code/ssurgo2apsim.R")

h <- downloadSSURGO(SiteName = "ISU Sorenson", 
                    # Set soil layer structure (in cm)
                    soilLayer_breaks = c(5,20,50,80,120,180), 
                    # Set field extent (in Decimal Degrees)
                    north=42.012351, # Latitude
                    south=42.010515, # Latitude
                    east=-93.737968, # Longitude
                    west=-93.742707, # Longitude
                    by_soil = TRUE,
                    map = TRUE) 

The function will return a list of objects inclding: site_name, field centroid coordinates.

h$site_name
# [1] "ISU Sorenson"

h$coordinates
# [1]  42.01235 -93.73797

If map = TRUE, then it also returns a map with the downloaded data.

h$map

The soils object contains a list with information for each soil type including the percent of the field area covered and a table for the APSIM-relevant variables. These are interportated according to the defined layer structure. This data will be used to set up APSIM soil profiles.

h$soils$Canisteo$area
# [1] 0.3081301

h$soils$Canisteo$horizon

layer	thick	CN2	sand	clay	wetbd	drybd	om	ksat	ll	dul	ph	bd
1	40	82.5	21.00000	32.00000	1.050000	1.150000	7.0000000	243.7338	0.1940000	0.3150000	7.410000	1.050000
2	140	82.5	23.14474	32.51398	1.156497	1.309474	5.9288651	245.0878	0.2055296	0.3218125	7.636296	1.156497
3	290	82.5	32.13656	26.99472	1.343194	1.492859	2.3362377	645.8077	0.1645688	0.2966529	8.203786	1.343194
4	290	82.5	45.40164	17.47388	1.543776	1.621767	0.5311222	792.5670	0.1078192	0.2558955	8.833126	1.543776
5	390	82.5	49.00000	15.00000	1.600000	1.660000	0.2500000	792.5670	0.0950000	0.2460000	9.000000	1.600000
6	590	82.5	49.00000	15.00000	1.600000	1.660000	0.2500000	792.5670	0.0950000	0.2460000	9.000000	1.600000

SSURGO2APSIM: Format downloaded data into APSIM toolbox

SSURGO2APSIM(h, crops = c("maize","soybean"),
             area_threshold = 0,
             include_Swim = FALSE, include_tile = FALSE)

# Creating APSIM toolbox with soils that occupy an area greather than 0% of the ISU Sorenson site.
 
# [1] "Canisteo: 31% of AOI"
# [1] "Clarion: 3% of AOI"
# [1] "Nicollet: 13% of AOI"
# [1] "Webster: 11% of AOI"