Plant N capture and microfaunal dynamics from decomposing grass and earthworm residues in soil

A  Hodge; J  Stewart; D  Robinson; B S  Griffiths; A H  Fitter

Plant N capture and microfaunal dynamics from decomposing grass and earthworm residues in soil

A Hodge, J Stewart, D Robinson, B S Griffiths, A H Fitter

Research output: Contribution to journal › Article › peer-review

Abstract

plant roots may be effective competitors with micro-organisms for the nutrients released from decomposing organic patches buried in soil. We aimed to establish whether this was because they were more effective at acquiring nutrients or simply because they represent a slower turnover pool. Over 30 days we followed decomposition of, and plant N capture from, dual labelled (N-15/C-13) earthworms (Lumbricus terrestris L.) and grass (Lolium perenne L. shoots) added as discrete patches to soil microcosm units containing L. perenne plants. Both patches decomposed rapidly as shown by the amounts of C-13, as (CO2)-C-13, released into the soil atmosphere, which peaked after 8 h for the earthworm patches and 48 h for the grass patches. In the decomposing grass patches the amounts of C-13 and N-15 remained co-varied and declined with time. No C-13 added in the earthworm patches was detected in the soils, even after 3 days, confirming that decomposition of these patches was rapid. Grass patches supported greater microfaunal (nematode and protozoan) biomass than the earthworm patches, and microfaunal biomass peaked at day 7 on both. Plant N capture from both patches increased with dry weight increment although N capture from the earthworm patch was greater than that from the grass patch. By day 30 plants had captured 29% (from earthworms) and 22% (from grass) of the N originally available in the patches. No C-13 enrichments from the patches were detected in the plant tissues indicating that organic compounds were not being taken up by the plant roots. As plants only took up inorganic N from the patch, our results indicate that microbes initially out-compete plants for the added N, but with time, plants capture more of the N originally added as they represent a slower turnover pool. (C) 2000 Elsevier Science Ltd. All rights reserved.

Original language	English
Pages (from-to)	1763-1772
Number of pages	10
Journal	Soil Biology and Biochemistry
Volume	32
Issue number	11-12
Publication status	Published - Oct 2000

Keywords

decomposition
organic patches
earthworms (Lumbricus terrestris L.)
Lolium perenne L
protozoa
nematodes
RICH ORGANIC PATCHES
ROOT PROLIFERATION
NITROGEN CAPTURE
AVAILABILITY
RESOURCES
NEMATODE
BACTERIA
GROWTH
FAUNA

Cite this

@article{13963ea02a81478fb00dd6cf80669c94,

title = "Plant N capture and microfaunal dynamics from decomposing grass and earthworm residues in soil",

abstract = "plant roots may be effective competitors with micro-organisms for the nutrients released from decomposing organic patches buried in soil. We aimed to establish whether this was because they were more effective at acquiring nutrients or simply because they represent a slower turnover pool. Over 30 days we followed decomposition of, and plant N capture from, dual labelled (N-15/C-13) earthworms (Lumbricus terrestris L.) and grass (Lolium perenne L. shoots) added as discrete patches to soil microcosm units containing L. perenne plants. Both patches decomposed rapidly as shown by the amounts of C-13, as (CO2)-C-13, released into the soil atmosphere, which peaked after 8 h for the earthworm patches and 48 h for the grass patches. In the decomposing grass patches the amounts of C-13 and N-15 remained co-varied and declined with time. No C-13 added in the earthworm patches was detected in the soils, even after 3 days, confirming that decomposition of these patches was rapid. Grass patches supported greater microfaunal (nematode and protozoan) biomass than the earthworm patches, and microfaunal biomass peaked at day 7 on both. Plant N capture from both patches increased with dry weight increment although N capture from the earthworm patch was greater than that from the grass patch. By day 30 plants had captured 29% (from earthworms) and 22% (from grass) of the N originally available in the patches. No C-13 enrichments from the patches were detected in the plant tissues indicating that organic compounds were not being taken up by the plant roots. As plants only took up inorganic N from the patch, our results indicate that microbes initially out-compete plants for the added N, but with time, plants capture more of the N originally added as they represent a slower turnover pool. (C) 2000 Elsevier Science Ltd. All rights reserved.",

keywords = "decomposition, organic patches, earthworms (Lumbricus terrestris L.), Lolium perenne L, protozoa, nematodes, RICH ORGANIC PATCHES, ROOT PROLIFERATION, NITROGEN CAPTURE, AVAILABILITY, RESOURCES, NEMATODE, BACTERIA, GROWTH, FAUNA",

author = "A Hodge and J Stewart and D Robinson and Griffiths, {B S} and Fitter, {A H}",

year = "2000",

month = oct,

language = "English",

volume = "32",

pages = "1763--1772",

journal = "Soil Biology and Biochemistry",

issn = "0038-0717",

publisher = "Elsevier",

number = "11-12",

}

TY - JOUR

T1 - Plant N capture and microfaunal dynamics from decomposing grass and earthworm residues in soil

AU - Hodge, A

AU - Stewart, J

AU - Robinson, D

AU - Griffiths, B S

AU - Fitter, A H

PY - 2000/10

Y1 - 2000/10

N2 - plant roots may be effective competitors with micro-organisms for the nutrients released from decomposing organic patches buried in soil. We aimed to establish whether this was because they were more effective at acquiring nutrients or simply because they represent a slower turnover pool. Over 30 days we followed decomposition of, and plant N capture from, dual labelled (N-15/C-13) earthworms (Lumbricus terrestris L.) and grass (Lolium perenne L. shoots) added as discrete patches to soil microcosm units containing L. perenne plants. Both patches decomposed rapidly as shown by the amounts of C-13, as (CO2)-C-13, released into the soil atmosphere, which peaked after 8 h for the earthworm patches and 48 h for the grass patches. In the decomposing grass patches the amounts of C-13 and N-15 remained co-varied and declined with time. No C-13 added in the earthworm patches was detected in the soils, even after 3 days, confirming that decomposition of these patches was rapid. Grass patches supported greater microfaunal (nematode and protozoan) biomass than the earthworm patches, and microfaunal biomass peaked at day 7 on both. Plant N capture from both patches increased with dry weight increment although N capture from the earthworm patch was greater than that from the grass patch. By day 30 plants had captured 29% (from earthworms) and 22% (from grass) of the N originally available in the patches. No C-13 enrichments from the patches were detected in the plant tissues indicating that organic compounds were not being taken up by the plant roots. As plants only took up inorganic N from the patch, our results indicate that microbes initially out-compete plants for the added N, but with time, plants capture more of the N originally added as they represent a slower turnover pool. (C) 2000 Elsevier Science Ltd. All rights reserved.

AB - plant roots may be effective competitors with micro-organisms for the nutrients released from decomposing organic patches buried in soil. We aimed to establish whether this was because they were more effective at acquiring nutrients or simply because they represent a slower turnover pool. Over 30 days we followed decomposition of, and plant N capture from, dual labelled (N-15/C-13) earthworms (Lumbricus terrestris L.) and grass (Lolium perenne L. shoots) added as discrete patches to soil microcosm units containing L. perenne plants. Both patches decomposed rapidly as shown by the amounts of C-13, as (CO2)-C-13, released into the soil atmosphere, which peaked after 8 h for the earthworm patches and 48 h for the grass patches. In the decomposing grass patches the amounts of C-13 and N-15 remained co-varied and declined with time. No C-13 added in the earthworm patches was detected in the soils, even after 3 days, confirming that decomposition of these patches was rapid. Grass patches supported greater microfaunal (nematode and protozoan) biomass than the earthworm patches, and microfaunal biomass peaked at day 7 on both. Plant N capture from both patches increased with dry weight increment although N capture from the earthworm patch was greater than that from the grass patch. By day 30 plants had captured 29% (from earthworms) and 22% (from grass) of the N originally available in the patches. No C-13 enrichments from the patches were detected in the plant tissues indicating that organic compounds were not being taken up by the plant roots. As plants only took up inorganic N from the patch, our results indicate that microbes initially out-compete plants for the added N, but with time, plants capture more of the N originally added as they represent a slower turnover pool. (C) 2000 Elsevier Science Ltd. All rights reserved.

KW - decomposition

KW - organic patches

KW - earthworms (Lumbricus terrestris L.)

KW - Lolium perenne L

KW - protozoa

KW - nematodes

KW - RICH ORGANIC PATCHES

KW - ROOT PROLIFERATION

KW - NITROGEN CAPTURE

KW - AVAILABILITY

KW - RESOURCES

KW - NEMATODE

KW - BACTERIA

KW - GROWTH

KW - FAUNA

M3 - Article

SN - 0038-0717

VL - 32

SP - 1763

EP - 1772

JO - Soil Biology and Biochemistry

JF - Soil Biology and Biochemistry

IS - 11-12

ER -