Why did the Jamestown colony have so little food in its early years

The Jamestown colony had little food in the early years for multiple reasons:

1) Lack of knowledge regarding terrain - Considering that this was the first permanent English settlement, the colonists were unaware of the climate and the weather and how this would affect crops on a long term basis.

2) Conflicts with Native Americans - The establishment of the Jamestown colony was not well received by many Native American groups, as they viewed the English as enroaching on their territory. This limited what resources/where the colonists could travel.