Soil Fertility

(515) 294-7078

Soil Test Interpretations and Recommendations

Use new potassium soil test and fertilizer recommendations (10/2003)
Interpreting results of the Mehlich-3 ICP soil phosphorus test (11/2003)
Nitrate testing: early versus late spring (2/2001)
Soil testing and available phosphorus (9/2000)
Effective use of precision agriculture for improved management of phosphorus, potassium and lime (5/1999)
Interpreting P and K soil test results (1/1999)

Mallarino, A.P. 2002. Revised Iowa P and K recommendations: New soil-test K interpretations and support for a new soil P test. p. 161-169. In The Integrated Crop Management Conf. Proceedings. Dec. 4-5, Ames, IA. Iowa State Univ. Extension. (pdf)
Mallarino, A.P., D.J. Wittry, and P.A. Barbagelata. 2002. Iowa soil-test field calibration research update: potassium and the Mehlich-3 ICP phosphorus test. p. 29-39. In North Central Extension-Industry Soil Fertility Conference. Proceedings. Vol. 18. Des Moines, IA. (pdf)
Sawyer, J.E. 1999. Making every fertilizer dollar pay. p. 63-78. In Proc. Integrated Crop Manag. Conf., Ames, IA. 1-2 Dec. Iowa State Univ., Ames, IA. (pdf)
Mallarino, A.P., and D. Wittry. 1999. Challenges for making intensive soil sampling and variable-rate technology pay. p.104-109. In North Central Extension-Industry Soil Fertility Conference. Proceedings. Vol. 15. St. Louis, MO.
Sawyer, J.E. 1998. Managing crop nutrients and limestone with reduced financial resources. p. 33-36. In Proc. Integrated Crop Manag. Conf., Ames, IA. 17-18 Nov. Iowa State Univ., Ames, IA. (pdf)