The high phosphorus reading is
very common in Texas soils, especially if you have heavy clay. You probably would have had a high reading before ever amending the soil. The high phos can lead to iron deficiency among other problems. There's not much you can do other than avoid adding phosphorus as was recommended.
It should also be noted that there is some controversy as to the validity of the test. You probably had your test done by A&M. The organic garden promoters in Texas (Howard Garrett, Malcolm Beck) claim that test done by A&M always incorrectly shows high phosphorus and that you should ignore this or get a test done by someone else that they endorse.
http://www.dirtdoctor.com/view_question.php?id=351
http://froebuck.home.texas.net/toppage.htm
...I personally support the Aggies on this one.
Jason