Phosphorus
Extension Publications
- Agricultural Phosphorus Management and Water Quality Protection in the Midwest
- CROP 3153 Phosphorus and Potassium Tissue Testing in Corn and Soybean
- PM 869 Fertilizing Pastures
- PM 1688 A General Guide for Crop Nutrient and Limestone Recommendations in Iowa
- PM 1993 Ten Questions about the Phosphorus (P) Index in Iowa
- PM 3052c Nutrient Considerations with Corn Stover Harvest
- SP 0435A Reducing Nutrient Loss: Science Shows What Works
Presentations
- Soil phosphorus and potassium dynamics and management. A.P. Mallarino. 2020. Soil fertility and nutrient management short course. Iowa State University Extension and Outreach, Ames.
- Site-specific soil fertility management, with emphasis on P, K, and lime. A.P. Mallarino. 2020. Soil fertility and nutrient management short course. Iowa State University Extension and Outreach, Ames.
Newsletter Articles
- Nutrient Replacement with Corn and Soybean Stover Removal (10/2024)
- Fall Phosphorus and Potassium Fertilization Decisions with Variable Prices (9/2023)
- Plant Tissue Testing may be Useful this Season but be Aware of Potential Drought Effects (6/2023)
- Phosphorus and Potassium Soil-Test Interpretation Guidelines Have Changed (2/2023)
- Cold Spring and High Fertilizer Prices may Make Starter Fertilizer More Important (4/2022)
- Wind damaged corn - nutrient content? (8/2020)
- Phosphorus and potassium management for 2020 after a year with highly variable yields (10/2019)
- You couldn’t apply phosphorus and potassium last fall and now it’s too wet (4/2018)
- Fertilization can help with cool soils and late planting dates (4/2018)
- Phosphorus and potassium in silage harvest of drought-damaged corn (7/2017)
- Value of soybean tissue testing for phosphorus and potassium (6/2016)
- Research shows a role for phosphorus and potassium tissue testing in corn (6/2016)
- Make rational decisions about phosphorus and potassium management with unfavorable crop prices (9/2015)
- Starter fertilization sometimes boosts corn yield (03/2015)
- Don't underestimate the value of starter fertilizer for corn planted late (5/2013)
- Phosphorus, potassium, and pH management issues following drought-damaged crops (8/2012)
- Phosphorus and potassium in silage harvest of drought-damaged corn (7/2012)
View newsletter articles 2015 and earlier -- click here to expand
Conference Proceedings and Reports
- Larson, A., E. Heaton, N. Boersma, J. Studt, S. Emran, and A. VanLoocke. 2024. Effect of phosphorus and potassium application on the growth and yield of a 14-year-old Miscanthus x giganteus stand. Proceedings, 54th North Central Soil Fertility Conf., Nov. 20-21, 2024.
- Mallarino, A.P., and K. Pecinovsky. 2024. Phosphorus and potassium fertilization for corn and soybean during 40 years in Northeast Iowa. Final research report. Iowa State University.
- Barker, R.W., M.J. Helmers, and M.D. McDaniel. 2023. Cereal rye cover crops mitigate soil phosphorus stratification from long-term no-tillage. Proceedings, 53rd North Central Soil Fertility Conf., Nov. 15-16, 2023.
- Mallarino, A.P. 2023. Iowa P and K soil-test interpretations were updated in 2023: Changes and Reasons. Proceedings, 53rd North Central Soil Fertility Conf., Nov. 1516, 2023.
- Mallarino, A.P., L.B. Thompson, J. Sievers, and T. Tuttle. 2020. Long-term phosphorus and potassium placement methods and application rates for corn and soybean managed with no-tillage and tillage. Iowa State Univ. Research and Demonstration Farms Progress Reports 2019. RFR-A1968.
- Mallarino, A.P., 2019. Phosphorus and potassium fertilizer placement options when crop prices are low. p. 123-130. In 31th Integrated Crop Management Conf. Proceedings. Dec. 4-5. 29-30, 2019. Iowa State Univ. Extension.
- Mallarino, A.P., 2019. Efficacy of variable-rate application technology for phosphorus, potassium, and lime management. In 49th North-Central Extension-Industry Soil Fertility Conf. Proceedings. Nov. 5-6. Des Moines, IA.
- Mallarino, A.P., 2018. Corn and soybean grain yield, phosphorus and potassium removal, and soil-test trend responses to long-term fertilization strategies. p. 83-90. In 30th Integrated Crop Management Conf. Proceedings. Nov. 28-29, 2018. Iowa State Univ. Extension.
- Mallarino, A.P., and J.D. Jones. 2018. Correlation of the weak organic acids test of a soil health tool with crop yield response to phosphorus fertilization. p. 14-20. In 48th North-Central Extension-Industry Soil Fertility Conf. Proceedings. 14-15 Nov. 2018. Vol. 34. Des Moines, IA. International Plant Nutrition Institute, Peachtree Corners, GA.
- Mallarino, A.P., and K. Pecinovsky. 2017. Phosphorus and potassium placement for corn and soybean managed with tillage or no-tillage. Farm Progress Reports: Vol. 2016: Iss. 1, Article 76.
- Mallarino, A.P. 2016. Value of tissue testing to improve phosphorus, potassium, and micronutrients management for corn and soybean. p. 139-146. In The Integrated Crop Management Conf. Proceedings. Nov. 30-Dec. 1, 2016. Iowa State Univ. Extension.
- Mallarino, A.P. 2016. What can long term experiments provide for improving phosphorus and potassium management? p. 12-16. In 65th North-Central Extension-Industry Soil Fertility Conf. Proceedings. Nov. 2-3 2016. Vol. 32. Des Moines, IA. International Plant Nutrition Institute, Brookings, SD.
- Mallarino, A.P., and M.U. Haq. 2016. How can fertilizer and manure management practices reduce dissolved phosphorus loss from fields and improve water quality? p. 179-184. In The Integrated Crop Management Conf. Proceedings. Nov. 30-Dec. 1, 2016. Iowa State Univ. Extension.
- Mallarino, A.P., B. Havlovic, and D. Schaben. 2016. Effects of phosphorus and potassium placement on yield of corn and soybean managed with tillage or no tillage. Armstrong and Neely-Kinyon Research and Demonstration Farms Annual Reports. ISRF15-12, RFR-A1594. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and J. Sievers. 2016. Phosphorus and potassium placement and application rates for corn and soybean managed with no-till or tillage. Northwest Research Farm and Allee Demonstration Farm Annual Reports. ISRF15-29,31, RFR-A1563. Iowa State Univ., Ames, IA.
- Mallarino, A.P. 2015. Making rational adjustments to phosphorus, potassium, and lime application rates when crop prices are low and producers want to cut inputs. p. 149-155. In The Integrated Crop Management Conf. Proceedings. Dec. 2-3, 2015. Iowa State Univ. Extension.
- Mallarino, A.P., and M.U. Haq. 2015. Phosphorus loss with runoff after applying fertilizer or manure as affected by the timing of rainfall. p. 94-99. In 45th North-Central Extension-Industry Soil Fertility Conf. Proceedings. Nov. 19-20 2014. Vol. 31. Des Moines, IA. International Plant Nutrition Institute, Brookings, SD.
- Mallarino, A.P., P. Barbieri, and K. Pecinovsky. 2015. Long-term phosphorus and potassium fertilization effects on yields of corn and soybean grown in rotation. Northeast Research and Demonstration Farm Annual Reports. ISRF14-13, RFR-A14104. Iowa State Univ., Ames, IA.
- Mallarino, A.P. 2014. Making rational adjustments to phosphorus, potassium, and lime application rates when crop prices are low and producers want to cut inputs. p. 137-143. In The Integrated Crop Management Conf. Proceedings. Dec. 3-4, 2014. Iowa State Univ. Extension.
- Mallarino, A.P. 2013. Interpretation of plant tissue test results for phosphorus and potassium in corn and soybean. In Proc. 2013 North-Central Region Soil and Plant Analysis and NCERA-13 Workshop, Feb. 26-27, Iowa City, IA.
- Mallarino, A.P., and D. Rueber. 2013. Alfalfa hay and soil-test phosphorus responses to long-term phosphorus fertilization strategies. Northern Research and Demonstration Farm Annual Reports. ISRF12-22. Iowa State Univ., Ames, IA.
- Thompson, L.B., A.P. Mallarino, and K.T. Pecinovsky. 2013. Crop response to phosphorus fertilizer or phosphorus recovered as struvite from corn fiber processing for bioenergy. Northeast Research and Demonstration Farm Annual Reports. ISRF12-13. Iowa State Univ., Ames, IA.
- Sawyer, J.E., and A.P. Mallarino. 2012. Nutrient considerations with corn silage and stover harvest. p. 131-136. In The Integrated Crop Management Conf. Proceedings. Nov. 28-29, 2012. Iowa State Univ. Extension.
- Mallarino, A.P., R.R. Oltmans, J.R. Prater, C.X. Villavicencio, and L.B. Thompson. 2011. Nutrient Uptake by Corn and Soybean, Removal, and Recycling with Crop Residue. p. 103-113. In Proc. 23rd Annual Integrated Crop Management Conf., Ames, IA 30 Nov. – 1 Dec. 2011. Iowa State Univ., Ames, IA
- Oltmans, R.R., and A.P. 2011. Phosphorus and potassium removal and leaching from residue in corn and soybean. p. 197-202. In North-Central Extension-Industry Soil Fertility Conf. Proceedings. Nov. 16-17. Vol. 27. Des Moines, IA
- Mallarino, A.P., and D. Rueber. 2010. Phosphorus fertilization strategies for alfalfa hay, production followed by corn harvested for grain. Northern Research and Demonstration Farm Annual Reports. RFR-A9108. ISRF09-22. Iowa State Univ., Ames, IA.
- Mallarino, A.P. 2009. Phosphorus and potassium placement methods for corn and soybean: an Iowa perspective. p. 109-115. In Proc. 2009 Wisconsin Crop Management Conf., Madison, WI. Vol. 48. Univ. Wisconsin-Extension and College of Ag. And Life Sciences, Univ. of Wisconsin-Madison, WI.
- Mallarino, A.P. 2009. Long term phosphorus studies and how they effect recommendation philosophies. p. 5-12. In Proc. Thirty-Ninth North Central Extension-Industry Soil Fertility Conf., Des Moines, IA. 18-19 Nov. 2009. Vol. 25. International Plant Nutrition Inst., Brookings, SD.
- Mallarino, A.P. 2008. Fertilizing crops in the new price age - phosphorus and potassium. p. 261-266. In Proc. 20th Annual Integrated Crop Manag. Conf., Ames, IA. 10-11 Dec. 2008. Iowa State Univ., Ames, IA
- Mallarino, A.P., and J. Prater. 2007. Corn and soybean grain yield, phosphorus removal, and soil-test responses to long-term phosphorus fertilization strategies. In Proc. 19th Annual Integrated Crop Manag. Conf., Ames, IA. 28-29 Nov. 2007. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and D.J. Wittry. 2006. Variable-rate application for phosphorus and potassium: impacts on yield and nutrient management. p. 219-224. In Proc. 18th Annual Integrated Crop Manag. Conf., Ames, IA. 29-30 Nov. 2006. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and R. Borges. 2005. Broadcast and deep band placement of phosphorus for soybeans managed with ridge tillage. Better Crops Plant Food 89(1):8-11.
- Mallarino, A.P., M.U. Haq, and K. Pecinovsky. 2005. Runoff phosphorus loss as affected by tillage, fertilizer, and swine manure phosphorus management in corn-soybean production systems. p. 46-47. In Annual progress reports-2004. Northeast research and demonstration farm. ISRF04-13. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and D. Rueber. 2005. Phosphorus and potassium fertilization and placement methods for corn-soybean rotations managed with no-till and chisel plow tillage. p. 12-13. In Annual progress reports-2004. Northern Research and Demonstration farm. ISRF04-22. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and K. Pecinovsky. 2005. Phosphorus and potassium placement methods for corn and soybeans managed with no-till and chisel plow tillage. p. 44-45. In Annual progress reports-2004. Northeast research and demonstration farm. ISRF04-13.
- Mallarino, A.P. 2004. On-farm implementation of the phosphorus index: Observed risk ratings and impacts on fertilizer and manure phosphorus management. p. 145-152. In The Integrated Crop Management Conf. Proceedings. Dec. 1-3, Ames, IA. Iowa State Univ. Extension.
- Mallarino, A.P., and K. Pecinovsky. 2004. Long-term phosphorus and potassium fertilization strategies for corn-soybean rotations. p. 22-23. In Annual progress reports-2003. Northeast research and demonstration farm. ISRF03-13. Iowa State Univ., Ames, IA.
- Kanwar, R., J. Baker, C. Pederson, A.P. Mallarino, J. Sawyer, and K. Pecinovsky. 2004. Impact of swine manure applications on nitrate and phosphorus in subsurface drainage water. p. 26-27. In Annual progress reports-2003. Northeast research and demonstration farm. ISRF03-13. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and D. Rueber. 2004. Long-term phosphorus fertilization for corn-soybean rotations. p. 12-13. In Annual progress reports-2003. Northern Research and Demonstration farm. ISRF03-22. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and D. Haden. 2004. Phosphorus and potassium placement for corn and soybeans managed with no-till and chisel-disk tillage. p. 14-15. In Annual progress reports-2003. Northwest research and demonstration farm. ISRF03-29,31. Iowa State Univ., Ames, IA.
- Mallarino, A.P., B. Havlovic, and J. Butler. 2004. Phosphorus and potassium fertilizer placement for corn and soybeans managed with no-till and chisel-disk tillage. p. 19-20. In Annual progress reports-2003. Armstrong research and demonstration farm. ISRF00-12. Iowa State Univ., Ames, IA.
- Mallarino, A.P., J. Sawyer, J. Klatt, R. Kanwar, C. Pederson, J. Baker, and K. Pecinovsky. 2003. Fertilizer and swine manure management systems: impacts on agronomic and environmental soil phosphorus tests and on phosphorus loss with subsurface drainage. Annual progress reports-2002. Northeast Research and Demonstration farm. ISRF02-13. Iowa State Univ., Ames, IA.
- Mallarino, A.P. 2003. Starter and foliar fertilization. Are they needed to supplement primary fertilization? p. 113-120. In The Integrated Crop Management Conf. Proceedings. Dec. 3-4, Ames, IA. Iowa State Univ. Extension.
- Mallarino, A.P. 2003. Using the Iowa phosphorus index for agronomic and environmental management of fertilizer and manure phosphorus. p. 121-126. In The Integrated Crop Management Conf. Proceedings. Dec. 3-4, Ames, IA. Iowa State Univ. Extension.
- Kaiser, D.E., A.P. Mallarino, and M. Bermudez. 2003. In-furrow starter and broadcast phosphorus and potassium fertilization for corn. p. 186-189. In North-Central Extension-Industry Soil Fertility Conf. Proceedings. Vol. 19. Des Moines, IA.
- Mallarino, A.P., and D. Rueber. 2003. Long-term evaluation of nitrogen, phosphorus, potassium, and lime requirements of continuous corn. p. 7-8 In Annual progress reports-2002. Northern Research and Demonstration farm. ISRF02-22. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and K. Van Dee. 2003. Phosphorus and potassium placement for corn and soybeans managed with no-till and chisel-plow tillage. Annual progress reports-2002. Northwest Research and Demonstration farm. ISRF02-34. Iowa State Univ., Ames, IA.
- Klatt, J.G., A.P. Mallarino, and B.L. Allen. 2002. Relationships between soil phosphorus and phosphorus in surface runoff and subsurface drainage. An overview of ongoing research. p. 183-189. In North-Central Extension-Industry Soil Fertility Conf. Proceedings. Vol. 18. Des Moines, IA.
- Mallarino, A.P., D. Wittry, and J. Klatt. 2001. Using the Iowa phosphorus index and variable-rate technology for effective agronomic and environmental phosphorus management. p. 151-158. In The Integrated Crop Management Conf. Proceedings. Dec. 5-6, 2001, Ames, IA. Iowa State Univ. Extension.
- Mallarino, A.P., and D. Wittry. 2000. How can we make intensive soil sampling and variable-rate P and K fertilization cost-effective? p. 203-210. In The Integrated Crop Management Conf. Proceedings. Nov. 29-30, 2000. Ames, IA. Iowa State Univ. Extension.
- Sawyer, J.E. and D. Barker. 1999. Foliar fertilization of corn with mono-potassium phosphate and urea. Final research report. Iowa State Univ., Ames, IA
- Mallarino, A.P. 1999. Alternatives for P and K management: A role for deep banding and starter? p. 247-253. In The Integrated Crop Management Conference. Proceedings. Dec. 1-2, 1999. Iowa State Univ. Extension. Ames, IA.
- Mallarino, A.P. 1999. Soil phosphorus testing for crop production and environmental purposes. p. 185-192. In The Integrated Crop Management Conf. Proceedings. Dec. 1-2, 1999. Ames, IA. Iowa State Univ. Extension.
- Mallarino, A.P., and D. Rueber. 1998. Evaluation of superphosphate and rock phosphate for a corn-oat-forage rotation. p. 6-8. In Annual progress reports-1997. Northern research and demonstration farm. ISRF97-22. Iowa State Univ., Ames, IA.
- Mallarino, A.P., and Haq, M.U. 1998. Foliar fertilization of soybeans. p. 20-26. In North Central Extension-Industry Soil Fertility Conference. Proceedings. Vol. 14. St. Louis, MO.
- Mallarino, A.P., D.W. Barker, R. Borges, and J.C. North. 1998. Tillage and fertilizer placement for the corn-soybean rotation. p. 231-237. In The Integrated Crop Management Conference. Proceedings. Nov. 17-18, 1998. Iowa State Univ. Extension, Ames, IA.
- Mallarino, A.P., D.J. Wittry, D. Dousa, and P.N. Hinz. 1998. Variable-rate phosphorus fertilization: On-farm research methods and evaluation for corn and soybean. p. 687-696. In P.C. Robert et al. (ed.). Proceedings, 4d. Int. Conf. on Site-Specific Management for Agricultural Systems. July 19-22, 1998 Minneapolis, MN. ASA, SSSA, ASA. Madison, WI.
View conference proceedings and reports 2016 and earlier -- click here to expand
Featured Publication
Phosphorus and Potassium Tissue Testing in Corn and Soybean
Antonio Mallarino, John Sawyer
Provides the first interpretation guidelines for using tissue testing for these nutrients in corn and soybean.
Antonio Mallarino, John Sawyer
Provides the first interpretation guidelines for using tissue testing for these nutrients in corn and soybean.
Links
- Iowa NRCS Phosphorus Index
- Iowa Department of Natural Resources, Animal Feeding Operations
- SERA 17 - Minimizing Phosphorus Losses from Agriculture
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