material	variablename	variabledescription	Units	instrumentusedforanalysis	methodused	labwhereanalysiswasconducted	yearanalysiswasconducted	I	J
""	"SSN"	"Sample serial number"	""	""	""	""			
""	"Study"	"Project name"	""	""	""	""			
""	"Region"	"Region where study is being conducted"	""	""	""	""			
""	"Country"	"Country name"	""	""	""	""			
""	"Sampling"	"Sampling design"	""	""	""	""			
""	"Site"	"Sentinel site name"	""	""	""	""			
""	"Cluster"	"Cluster number"	""	""	""	""			
""	"Plot"	"Plot number"	""	""	""	""			
""	"Depth"	"Topsoil = 0-20 cm depth; Subsoil = 20-50 cm depth"	""	""	""	""			
"Soil"	"pH"	"Soil pH in water (soil: water ratio of 1:2 weight to volume basis)"	""	"Voltmeter"	"Potentiometric"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"EC (Salts)"	"Soil electrical conductivity"	"uS/cm"	"Electroconductivity meter"	"Potentiometric"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Exchangeable Acidity"	"Exchangeable Acidity"	"meq/100g"	"Titration"	"Titration with standardized base, sodium hydroxide"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Phosphorus"	"Phosphorus by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Potassium"	"Potassium concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Calcium"	"Exchangeable calcium concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Magnesium"	"Exchangeable Magnesium by wet method"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Manganese"	"Exchangeable Manganese concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Sulphur"	"Sulphur by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Copper"	"Copper concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Boron"	"Boron concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Zinc"	"Zinc by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Aluminium"	"Exchangeable aluminium concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Sodium"	"Exchangeable Sodium concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Iron"	"Iron concentration by Mehlich 3 extraction"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Mehlich-3"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"CEC"	"Cation Exchange Capacity"	"meq/100g"	""	""	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"PSI"	"Phosphorus Sorption Index"	"mg kg^-1"	"Optical Emission spectrometry ( ICP-OES)"	"Extraction with Potassium dihydrogen orthophosphate (75 mg P L-1 in 0.03M KCl)"	"Crop Nutrition Laboratory"	2021.0		
"Soil"	"Total Nitrogen"	"Total Nitrogen content"	"% by weight"	"Thermo Scientific FLASH 2000"	"Dry combustion"	"Iso-Analytical Lab, UK,Web: www.iso-analytical.co.uk"	2021.0		
"Soil"	"Soil Organic Carbon"	"Carbon content of acid treated sample to remove carbonates"	"% by weight"	"Thermo Scientific FLASH 2000"	"Carbonates dissolution by acidification then Dry combustion"	"Iso-Analytical Lab, UK,Web: www.iso-analytical.co.uk"	2021.0		
"Soil"	"w4001.614118 to w601.688484"	"Wavenumbers"	"cm^-1"	"Bruker HTS-XT spectrometer"	"Diffuse Reflectance Fourier Transform spectroscopy"	"ICRAF"	2021.0		
