You've incorrectly defined these properties:
LandLookup.LookupBoundField = "Land";
LandLookup.LookupDisplayField = "Land";
for example, your table Land has two fields:
int LandId; //unique id of country
string LandName; //name of the country
and has following values:
LandId | LandName
------------------------
1 | USA
2 | UK
3 | Canada
4 | France
5 | Germany
LookupBoundField - is a field for lookup data. In this case this is a LandId field.
LookupDisplayField - is a field name that used to display data from lookup table. In this case this is a LandName field.
LandLookup.LookupBoundField = "LandId";
LandLookup.LookupDisplayField = "LandName";