magnesium sulphate heptahydrate agriculture grade

Magnesium sulfate heptahydrate (Agriculture grade): 
Appearance White small granular 
Main content 99.5% min 
MgSO4 48.59% min 
MgO 16.27% min 
Mg 9.81% min 
PH(5W/V%Sol) 5-8 
Ferron(Fe) 0.002% max 
Chloride(CL) 0.002%
 
Heavy metal (Pb) 0.001 %max 
Arsenic(As) 0.0002% max 
Insoluble 0.01%max 
Size (mm) 0.1-1 0.2-3 1-4