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Abstract
Managing soils to retain new plant inputs is key to moving toward a sustainable and regenerative agriculture. Management practices, like diversifying and perennializing agroecosystems, may affect the decomposer organisms that regulate how new residue is converted to persistent soil organic matter. Here we tested whether 12 years of diversifying/perennializing plants in agroecosystems through extended rotations or grassland restoration would decrease losses of new plant residue inputs and, thus, increase retention of carbon (C) and nitrogen (N) in soil. We tracked dual-labeled (13C and 15N), isotopically enriched wheat (Triticum aestivum) residue in situ for 2 years as it decomposed in three agroecosystems: maize–soybean (CS) rotation, maize–soybean–wheat plus red clover and cereal rye cover crops (CSW2), and spring fallow management with regeneration of natural grassland species (seven to 10 species; SF). We measured losses of wheat residue (Cwheat and Nwheat) in leached soil solution and greenhouse gas fluxes, as well as how much was recovered in microbial biomass and bulk soil at 5-cm increments down to 20 cm. CSW2 and SF both had unique, significant effects on residue decomposition and retention dynamics that were clear only when using nuanced metrics that able to tease apart subtle differences. For example, SF retained a greater portion of Cwheat in 0–5 cm surface soils (155%, p = 0.035) and narrowed the Cwheat to Nwheat ratio (p < 0.030) compared to CS. CSW2 increased an index of carbon-retention efficiency, Cwheat retained in the mesocosm divided by total measured, from 0.18 to 0.27 (49%, p = 0.001), compared to CS. Overall, we found that diversifying and extending the duration of living plants in agroecosystems can lead to greater retention of new residue inputs in subtle ways that require further investigation to fully understand.
Department
Soil Biogeochemistry and Microbial Ecology; Natural Resources and the Environment
Publication Date
12-7-2022
Journal Title
Functional Ecology
Publisher
Wiley
Digital Object Identifier (DOI)
Document Type
Article
Recommended Citation
McDaniel, Marshall D., Bird, Jeffrey A., Pett-Ridge, Jennifer, Marin-Spiotta, Erika, Schmidt, Tom M., and Grandy, A. Stuart. 2023. “ Diversifying and Perennializing Plants in Agroecosystems Alters Retention of New C and N from Crop Residues.” Ecological Applications 33(2): e2784. https://doi.org/10.1002/eap.2784
Rights
© 2022 The Authors. Ecological Applications published by Wiley Periodicals LLC on behalf of The Ecological Society of America.
Comments
This is an Open Access article published by Wiley in Ecological Applications in 2022, available online: https://dx.doi.org/10.1002/eap.2784