Split tomatoes is caused by over watering and / or heavy rain. When tomatoes get too much water the inside of the tomato will grow much faster than the outside skin can keep up with. The skin then splits.
Use more organic mulch and water deeply. Other problems associated with water issues include -
Lower immunity to pests and disease
Lower quality tomatoes
Blossom End Rot.
Blossom End Rot is caused by irregular watering and fluctuating moisture, drought and over saturation will reduce calcium uptake into the plant. A lack of calcium leads to Blossom end rot.