Nitrogenous fertilizers have nearly doubled global grain yields, but have also increased losses of reactive N to the environment. Current public investments to improve soil health seek to balance productivity and environmental considerations. However, data integrating soil biological health and crop N response to date is insufficient to reliably drive conservation policy and inform management. Here we used multilevel structural equation modeling and N fertilizer rate trials to show that biologically healthier soils produce greater corn yields per unit of fertilizer. We found the effect of soil biological health on corn yield was 18% the magnitude of N fertilization, Moreover, we found this effect was consistent for edaphic and climatic conditions representative of 52% of the rainfed acreage in the Corn Belt (as determined using technological extrapolation domains). While N fertilization also plays a role in building or maintaining soil biological health, soil biological health metrics offer limited a priori information on a site’s responsiveness to N fertilizer applications. Thus, increases in soil biological health can increase corn yields for a given unit of N fertilizer, but cannot completely replace mineral N fertilization in these systems. Our results illustrate the potential for gains in productivity through investment in soil biological health, independent of increases in mineral N fertilizer use.
|State||Published - Dec 1 2020|
Bibliographical noteFunding Information:
We thank the growers who have allowed us access to their farms, as well as the many field crews who have helped set up, sample, and monitor these sites. We also acknowledge James Camberato and Meghan Moser for their contributions of data to this study. This research was supported by the Foundation for Food and Agriculture Research under Grant ID 534284. The content of this publication is solely the responsibility of the authors and does not necessarily represent the official views of the Foundation for Food and Agriculture Research. We also acknowledge the anonymous reviewers whose comments helped clarify and refine this manuscript.
© 2020, The Author(s).
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