首页|Plant species and plant neighbor identity affect associations between plant assimilated C inputs and soil pores

Plant species and plant neighbor identity affect associations between plant assimilated C inputs and soil pores

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? 2021 Elsevier B.V.Greater plant diversity is known to facilitate soil C gains, yet the exact mechanisms of this effect are still under intensive discussion. Whether a plant grows in monoculture or in a multi-species mixture can affect allocation of plant assimilates, belowground exudation, and microbial stimulation. The goal of this study was to examine the effects of inter-cropping on a previously overlooked aspect of plant-soil interactions, namely, on locations where plant assimilated C is allocated within the soil pore system and its subsequent fate in relation to soil pore size distributions. The soil for the study originated from a greenhouse experiment with switchgrass (Panicum virgatum L.) (var. Cave'n'Rock) (SW), big bluestem (Andropogon gerardii Vitman) (BB), and wild bergamot (Monarda fistulosa L.) (WB) grown in monocultures and in inter-cropped pairs and subjected to species specific 13C pulse labeling (Kravchenko et al., 2021). Intact soil cores (8 mm ?) were collected from the experimental pots, subjected to a short-term (10 day) incubation, X-ray computed micro-tomography (μCT) scanning, and soil 13C micro-sampling “geo-referenced” to μCT images. Results indicated that in the plant systems with demonstrated interplant C transfer soil 13C was positively correlated with < 10 μm ? pores immediately after plant termination and with 20–80 μm ? pores after the incubation. In the systems without marked interplant C transfer soil, 13C was positively correlated with 20–30 μm ? pores, however, the correlations disappeared after the incubation. Soils from the systems with demonstrated belowground C transfer displayed lower losses of root-derived C during incubation than the systems where interplant C transfer was negligible. Factors facilitating interplant C transfer appear to also lead to placement of root-derived C into smaller pores and to its greater protection there.

13CO2 pulse labelingBig bluestemPlant neighbor identityPore-size distributionPrairieSoil pore architectureSoil pore structureSwitchgrassWild bergamotX-ray computed micro-tomography

Zheng H.、Guber A.K.、Kravchenko A.N.、Kuzyakov Y.、Zhang W.

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Research Institute of Agricultural Resources and Environment Jilin Academy of Agricultural Science

Department of Plant Soil and Microbial Sciences Michigan State University

Department of Agricultural Soil Science University of G?ttingen

College of Geographical Sciences Inner Mongolia Normal University

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2022

Geoderma: An International Journal of Soil Science

Geoderma: An International Journal of Soil Science

ISSN:0016-7061
年,卷(期):2022.407
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