As an Iowa State University professor of agronomy, soil fertility researcher and Extension specialist, Antonio Mallarino has a long history of service to Iowa farmers. During his 35 years on the ISU agronomy staff, he conducted valuable research, helping farmers better manage crop nutrients.
For his dedication to helping Iowa farmers and agriculture, Mallarino is receiving the 2025 Iowa Master Farmer Exceptional Service to Agriculture Award. He retired at the end of 2023 but continues keeping busy finishing research reports, writing articles, helping his graduate students, assisting ISU Extension, answering questions and providing information.
Several years ago, at the North Central Extension-Industry Soil Fertility Conference, one of the main topics was phosphorus management for profitable crop production and how to improve and protect water quality. When Mallarino was introduced as a speaker, a “photoshopped” image on the screen showed Superman with his face and a large P (instead of S) on his chest.
Affinity for Iowa
After 40 years of studying, working and living in Iowa, “I’m very thankful,” Mallarino says. “My wife and I came here to earn advanced degrees from Iowa State University. We accomplished that and liked Iowa. We stayed. Thank you, Iowa and Iowa agriculture.”
Raised on a dairy farm in Uruguay, Mallarino earned an undergraduate degree in agronomy and animal science at the University of Uruguay in 1975. He arrived at Iowa State University in 1979 and earned his master’s in soil fertility and crop production physiology in 1981. Then, he returned to Uruguay.
After working in Uruguay for several years, Mallarino and his wife returned to Iowa in 1986 so both could earn doctorate degrees. He completed his doctorate in crop production and physiology at ISU in 1988.
Instead of returning to his native Uruguay, Mallarino became an ISU professor of agronomy and Extension specialist. ISU offered him a staff position working with soil fertility research and soil testing. He took it with his wife’s strong support, liked it, later accepted a faculty position and devoted his career to helping Iowa farmers.
Improving nutrient management
Mallarino focused on phosphorus, potassium, lime, micronutrients, manure nutrient management, soil testing, plant analysis, the use of precision ag technology and management effects on phosphorus loss from fields. Assisted by graduate students and ISU colleagues, he improved ISU Extension crop nutrient management guidelines and helped develop the Iowa Phosphorus Index and the Nutrient Reduction Strategy.
He represented ISU at the USDA National Institute for Food and Agriculture, serving on the committee for soil testing and plant analysis and the committee for minimizing phosphorus losses from fields. He served on the North American oversight committee on soil testing proficiency, and for six years he was an associate editor of the Agronomy Journal and Soil Science Society of America Journal. He co-developed ISU’s Extension soil fertility website and continues to help maintain it.
Mallarino devoted time to working internationally, mostly in Argentina and Uruguay, doing collaborative outreach projects and advising on research development. He shared information on soil testing and plant analysis, improving fertility management for conservation tillage, minimizing nutrient loss and more. He is an honorary member of the graduate program at the University of Uruguay.
Always willing to help
Continuing to make himself available to discuss his research results for ISU Extension, Mallarino delivers his talks with great enthusiasm. Over the years, he joked about his speaking “Spanglish,” but that didn’t deter him from having a packed room wherever he spoke. His messages are clear and understandable, providing information and recommendations that farmers, consultants and the fertilizer industry need to know.
Mallarino has had a tremendous impact on Iowa farming and soil fertility issues to maximize profitability and simultaneously minimize the environmental effects of applying fertilizer, especially phosphorus.
“One example in which I was directly involved was a farmer who asked me to teach him how to create a soil fertility plan according to what Antonio recommends,” says Virgil Schmitt, an ISU Extension field agronomist. “A short time later, the farmer told me Antonio’s work saved him over $120,000 in fertilizer expenses. The positive impact Antonio has had on Iowa agriculture cannot be overstated.”
Master at a glance
Name: Antonio Mallarino
Family: Wife Emma Mallarino passed away in 2022. They have three daughters: Emma Mallarino Houghton, Maria H. Mallarino and Andrea L. Mallarino.
Location: Ames, Iowa
Position: Iowa State University professor of agronomy, nutrient research and Extension specialist. Retired Dec. 31, 2023.
Interesting fact: “I grew up on a dairy farm in Uruguay,” Mallarino says. “As a student earning a bachelor’s degree at the University of Uruguay, I had my first research plots in 1971. I did crop-fertility experiments on our home farm. That began my interest in soil fertility and nutrient management. When I retired at Iowa State University, it was the first fall since 1971 that I didn’t have field trials.”
A trusted adviser for farmers
Colleagues and farmers wrote strong letters of support for Mallarino’s nomination to receive the 2025 Iowa Master Farmer Exceptional Service to Agriculture Award.
“I’ve been fortunate to have worked with Dr. Mallarino,” says Matt Helmers, ISU professor and director of the Iowa Nutrient Research Center. “Throughout his 30-year career as a professor at Iowa State, Antonio has worked tirelessly to educate stakeholders on the importance and impacts of phosphorus management. It has profitability and environmental impacts.
“Antonio has been very successful in bringing this information to the forefront in his educational efforts. He is steadfast in advising farmers on best ways to manage fertilizer and soil fertility. He is a trusted adviser, telling farmers what they need to hear, not what someone wants them to hear. He delivers unbiased, science-based information.”
Mallarino’s work helps farmers understand the effects of their management on water quality. He was instrumental in developing the Iowa Phosphorus Index, for example. “This tool is important to manage phosphorus on millions of acres,” Helmers says. “Antonio has improved the profitability of Iowa farmers and lessened the environmental impacts of agriculture. He has provided exceptional service to Iowans. I’m proud to have worked with him. He’s a good friend who devoted his professional career to the producers in Iowa.”
Providing valuable support
“Our paths first met at the North Central Iowa Crops Clinic years ago,” says Stu Swanson, president of the Iowa Corn Growers Association. “It was the beginning of my farming career. I was a young swine producer. Antonio’s presentations helped me understand the value of manure and how to manage and apply it to maximize the return to crops we were fertilizing. His presentations and research-based information still have a significant impact today.”
Mallarino’s studies and recommendations also have been a helpful resource for crop consultants and industry agronomists. His studies have not only improved soil sampling and testing to fine-tune fertilizer application rates, but also placement and timing, Swanson says.
“This has helped us maximize yields without overapplying nutrients,” Swanson says. “Antonio has always been a go-to source for his peers in the agronomy sector and for farmers.”
Swanson adds that the ICGA’s board and its animal ag and environment committees have appreciated the help Antonio provided, particularly with his involvement with the Iowa Nutrient Research and Education Council.
“His studies and expertise in managing nutrients in reduced tillage and no-till continues to help farmers as we work to reduce our carbon intensity and improve sustainability of farms,” Swanson says. “His help has been invaluable to farmers and the state of Iowa in reaching goals outlined in the Iowa Nutrient Reduction Strategy.”