It talks about measuring Ph of water, but can it measure Ph of dirt?:
http://www.testequipmentdepot.com/milwaukee/ph-meters/ph600.htm?ganclickid=00048c38a7eeb9080a140e99c11c706d#0003226?ref=gbase
http://www.testequipmentdepot.com/milwaukee/ph-meters/ph600.htm?ganclickid=00048c38a7eeb9080a140e99c11c706d#0003226?ref=gbase