The 4Rs in crop nitrogen research

Abstract

The goal of nitrogen (N) application is for crop uptake, resulting in improved yield and quality of the crop harvested. However, N fertilizer applications are also susceptible to emission losses, as ammonia (NH 3 ) and nitrous oxide (N 2 O), and surface and groundwater losses as nitrate-N (NO 3 -). In the past, research has focused on the rate of nutrient application on yield, quality, and N losses. As producers look to improve nutrient use efficiency, the need for research to address other factors in nitrogen application has grown. Specifically, a growing number of researchers are looking at how the 4Rs of nutrient application-source, rate, time, and place-affect crop uptake and yields. The fertilizer industry established the 4R Research Fund to help establish sustainability indicators and environmental impact data for implementation of 4R nutrient stewardship across North America.Improved N use efficiency can be achieved through combinations of rate, source, time, and place. A recent roundtable meeting identified as a goal "broadening the focus of applied research beyond N rate to move toward more integrated agricultural systems," and cited the 4R nutrient stewardship approach as a step to help represent A growing number of researchers are looking at how the 4Rs of nutrient application-source, rate, time, and place-affect crop uptake and yields. This article begins a new series from The Fertilizer Institute highlighting some of the latest 4R research. Earn 0.5 CEUs in Nutrient Management by reading this article and taking the quiz at www.certifiedcropadviser.org/ certifications/self-study/825. crop nitrogen research

Slow-release nitrogen fertilizers enhance growth, yield, NUE in wheat crop and reduce nitrogen losses under an arid environment

“…The optimum N fertilizers rate proved to increase thousand-grain weight, protein contents, NUE, and wheat yield (Zhang et al 2015 ). To reduce the N losses and increase the yield, the 4R principle (right time, the right amount, right source, and right place) is suggested to adopt for fertilizers (Flis 2017 ). Further, it is also revealed 50 years ago by the law of diminishing return that ever increased fertilizer application will not be a good technique in enhancing crop’s yield (Pleijel et al 2019 ).…”

Enhanced‐efficiency fertilizers are not a panacea for resolving the nitrogen problem

“…(Supplemental measures such as altering human diets, reducing food waste, or enhancing the reuse of nutrients through recycling are other dimensions, beyond the scope of this study). One way to pursue greater NUE, long‐advocated and management‐driven, is the implementation of knowledge‐based fertilizer use practices, which can be summarized by the 4R principle (Davidson, Suddick, Rice, & Prokopy, ; Flis, ) ‐ right time (application), right amount (rate), right placement (e.g. incorporation below soil surface), and right product (e.g.…”

Enhancing eco-environmental sustainability and wheat security in China: a sequential knowledge-based nitrogen strategy aligned with regional targets

“…The exponentially growing demand for food and the need to maintain food production systems within planetary boundaries pose two serious challenges to global agricultural production 29 , which necessitate well-informed N management and a comprehensive understanding of N cycles 30,31 . This study utilized knowledge-based management practices such as slow-release N fertilizers and N application optimization strategies aligned with the 4R principles: right timing, right amount, right placement, and right product, to convert unnecessary N from farmers to higher productivity 32,33 . However, the 4R principles pose a signi cant challenge for millions of smallholders with limited resources and knowledge to apply intensi cation management 34,35 .…”