Infrastructure Research
Type	Current Level
 Housing	4 
 Commercial	0 
 Industry	0 
 Agriculture	15 
 Mining	0 

heres my current reseach, much better then splitting

then on a planet i would do

Manage Infrastructure
  Housing 	
108 
  Commercial 	
0 
  Industry 	
0 
  Agriculture 	
1,392 
  Mining 	
0

this is a 1500 land planet
so i do 1500/14 whivch gives me 108 housing this allows me to place more infra on agri thus getting more per turn