Queensland farmers are locking their gates and refusing mining companies access to their land in an escalating campaign driven by environmental and health concerns.

The campaign comes amid a spate of conditional Queensland government approvals for new resource projects in the state.

Premier Anna Bligh on Tuesday gave the go-ahead to a third LNG project to develop gas fields in central Queensland and pipe it to Gladstone for export.

The nod, subject to 600 conditions and federal government approval, came amid a fresh contamination scare at a coal seam gas (CSG) operation at Moranbah, west of Mackay.

The environmental group Friends of the Earth believes new gas projects are being approved too quickly and wants a moratorium on further CSG projects until environmental impacts are better understood.