values for columns using sql

i new to SQL say i have this:

SELECT sum(tonsharvested) as kaapstad2011
FROM T_harvest
where BlockNameID = "Kaapstad" and year(Dateofharvest) = "2011"

it gives me a column kaapstad2011 with sufficient values

why cant i just say

SELECT sum(tonsharvested) as kaapstad2010
FROM T_harvest
where BlockNameID = "Kaapstad" and year(Dateofharvest) = "2010"

to display kaapstad2010 next to column above?
Any advise on how to go further will help, cant seem to shift past this mental block.