Where is the home field advantage?

The Twins are 17 and 33 on the season and are 10-13 at home and 11-19 on the road. The overall Minnesota Twins ERA is 4.76 and is the worst of all 30 teams in major league baseball. The Twins ERA in 2010 was 3.99 and 11th overall. Target Field, is supposed to be a pitcher’s park, so I have this question for you. Why is the Twins ERA this season at home at Target Field at 5.25 and on the road the ERA is 4.41? How do you explain that? The Twins WHIP (walks and hits per inning pitched) of 1.424 is the 27th worst in all of baseball, at home it is 1.449 and on the road it is 1.407, why? The Twins have allowed 5.16 runs per game and are again dead last in baseball and almost 1 run per game worse than in 2010 when they were 4.17. So again I have to ask, why do the Twins allow 5.75 runs per game at home and only 4.77 on the road? I guess if I could answer these questions I would be more than just a Twins blogger. Maybe it is a curse that someone put on the Twins after they had the trees removed from center field?