The primary goal of the NutrientStar Program is to encourage evidence-based decisions regarding fertilizer choice, application, and management. The program will attain this goal by increasing the quantity and availability of data about the performance of commercially available tools that are marketed to improve nutrient use efficiency. For our purposes, nutrient use efficiency (NUE) is defined as unit of yield over unit of applied nutrient, and yield benefits as documented through production-scale, replicated research trials. We further clarify this goal below.

When applying fertilizers in an agricultural setting, more is not always better. Increasing fertilization rates often helps farmers improve their yield, but the costs associated with higher inputs can reduce profitability. Tools that improve NUE can reduce input costs by improving the performance and/or deployment of fertilization practices. NutrientStar aims to illuminate the conditions under which products perform best as well as the extent of their effectiveness.

Currently it is difficult to obtain unbiased information about NUE tools. NutrientStar will search for and present scientifically sound data about NUE tools, promote a common set of research standards to facilitate reporting of results from evaluations, and provide farmers with practical and easy to understand information.

The primary performance metric NutrientStar uses to gage the effectiveness of reviewed tools is NUE. However, NutrientStar recognizes that production goals are also important, and tools that deliver greater NUE can increase or decrease yields. NutrientStar will present information on tool and product NUE performance, while also reporting on the effects on yield, so farmers have the ability to discern for themselves what will best contribute to improved management.

In addition, obtaining optimal yields also requires attention to the 4 Rs of fertilizer management: using the Right rate, in the Right form, at the Right time, in the Right place. Many NUE tools can help farmers decide what combination of the 4 Rs is best for their fields while also improving yield.

While NutrientStar is always cognizant of the benefit NUE tools can have on both crop yield and profitability, some benefits can’t be measured in economic terms alone. One important benefit of improved NUE can be a reduction in the environmental effects of fertilizer use. Reducing the environmental effects of fertilization may take the form of reductions in: contaminated run off and leaching, atmospheric volatilization, nutrient immobilization, and soil degradation.

Accurately measuring and accounting for the environmental benefits of NUE tools is an important aspect of the tool assessment process and should be considered as an element of tool selection. Armed with information about the potential environmental improvements that a product or tool can offer, farmers can better articulate to the public the benefits obtained from their use of NUE tools and products.