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Chairperson Scientific Panel on Sustainable Plant Nutrition,
IPNI Canada

How do we most effectively increase nutrient use efficiency and minimize nutrient losses to the environment?


The most important word in this question is “we.” The important players include not only every segment of the fertilizer industry, but all those engaged in enhancing agricultural productivity. The nutrient use efficiency gains achieved so far have resulted from the collective works of those involved in crop breeding, genetic improvement, crop protection, precision agriculture, equipment for nutrient application, and education of farmers and their advisers, along with better products and decision support services. Players beyond the fertilizer industry remain essential to the team.


Increased nutrient use efficiency helps reduce nutrient losses, but it is not always enough. In some instances, small losses of specific nutrient forms hit the environment hard. Nitrous oxide losses, for example, comprise only a few percent of the nitrogen applied, yet form a large part of its carbon footprint. A “right source” solution—a nitrification inhibitor—could cut that loss by at least a third, even where it improves nutrient use efficiency only a little. In the case of phosphorus, “right time” and “right place” fertilizer applications could cut dissolved phosphorus loss enough to shrink algal blooms in Lake Erie, even where they don’t change rates of application or crop yields.


What are the most effective ways to educate farmers around the world about the 4Rs? 


Farmers want to know specifics. Precisely what source-rate-time-place combinations they should be using for their soils and crops, how much it will cost to change from what they are currently doing, and what impact it will have on their bottom line. The site-specific answers to those myriad questions are provided neither directly from the scientific literature nor from a single all-knowing adviser. No matter the scale of their operation, farmers learn by sharing experiences in implementing practices and monitoring results. The engagement of agri-retailers, crop advisers, extension workers and research scientists in participatory adaptive management is important, as is peer and community recognition for “doing the right thing.”


How can the latest agronomic findings be best shared and implemented on the farm?


The “latest” in agronomy is often overemphasized. The impact of a specific source-rate-time-place combination often depends on the weather. Thus it is important in sharing “the latest findings” to place them in the context of synthesis of past results. Practices need to be evaluated in terms of robustness to risks induced by weather. Information needs to be shared on the basis of trust relationships—developed through on-farm visits, meetings, field tours and demonstrations—among leading farmers and their nutrient service providers.


How can a multi stakeholder forum such as this one help to identify further research priorities into plant nutrition?


This Forum features thought leaders representing large segments of the global nutrient value chain, from the mining and manufacturing of plant nutrients to the nourishment of consumers. Within the 4R Nutrient Stewardship framework, decisions on source-rate-time-place combinations for nutrient applications are guided by anticipated and monitored outcomes. At the farm level, the measurable outcomes include land productivity, soil health and nutrient use efficiency. But outcomes impacting bigger picture issues—including water quality, air quality, greenhouse gases, biodiversity, and food security—also need to be considered. In a multi stakeholder forum there is opportunity to find consensus on material outcomes, and to identify practices with the highest level of synergy to achieve these outcomes. The Forum can align scientific research priorities more closely with the priorities of the stakeholders of the whole nutrient value chain.