Budgets for root-derived C and litter-derived C: comparison between conventional tillage and no tillage soils

Kisselle, K.; Garrett, Carol; Fu, Shenglei; Hendrix, Paul F.; Crossley, D. A.; Coleman, David C.; Potter, Robert

doi:10.1016/s0038-0717(01)00012-8

Cited by 54 publications

(21 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Such is not the case, as most studies report that litter decomposition rates are increased by incorporation into surface soils (Hamadi et al, 2000). In a control 14 C recovery experiment, Kisselle et al (2001) observed a faster turnover of litter-derived C when incorporated into the soil. Stemmer et al (1999) also report that the incorporation of cm-size shoot material to soil increases the rate of decomposition, although they suggest that this might not affect the final proportion of stabilised C. In addition, the dominant effect of ploughing on SOM dynamics is not stabilisation through increased contact between plant residues and soil particles.…”

Section: Physico-chemical Protection Through the Interaction With Minmentioning

confidence: 93%

Is soil carbon mostly root carbon? Mechanisms for a specific stabilisation

Rasse¹,

Rumpel²,

Dignac³

2005

Plant Soil

1,472

910

View full text Add to dashboard Cite

Understanding the origin of the carbon (C) stabilised in soils is crucial in order to device management practices that will foster C accumulation in soils. The relative contributions to soil C pools of roots vs. shoots is one aspect that has been mostly overlooked, although it appears a key factor that drives the fate of plant tissue C either as mineralized CO 2 or as stabilized soil organic matter (SOM). Available studies on the subject consistently indicate that root C has a longer residence time in soil than shoot C. From the few studies with complete datasets, we estimated that the mean residence time in soils of root-derived C is 2.4 times that of shoot-derived C. Our analyses indicate that this value is biased neither by an underestimation of root contributions, as exudation was considered in the analysis, nor by a priming effect of shoot litter on SOM. Here, we discuss the main SOM stabilisation mechanisms with respect to their ability to specifically protect root-derived SOM. Comparing in situ and incubation experiments suggests that the higher chemical recalcitrance of root tissues as compared to that of shoots is responsible for only a small portion, i.e. about one fourth, of the difference in mean residence time in soils of root-derived vs. shootderived C. This suggests that SOM protection mechanisms other than chemical recalcitrance are also enhanced by root activities: (1) physico-chemical protection, especially in deeper horizons, (2) micrometer-scale physical protection through myccorhiza and root-hair activities, and (3) chemical interactions with metal ions. The impact of environmental conditions within deeper soil layers on root C stabilisation appear difficult to assess, but is likely, if anything, to further increase the ratio between the mean residence time of root vs. shoot C in soils. Future advances are expected from isotopic studies conducted at the molecular level, which will help unravel the fate of individual shoot and root compounds, such as cutins and suberins, throughout soil profiles.

show abstract

Section: Physico-chemical Protection Through the Interaction With Minmentioning

confidence: 93%

Is soil carbon mostly root carbon? Mechanisms for a specific stabilisation

Rasse¹,

Rumpel²,

Dignac³

2005

Plant Soil

1,472

910

View full text Add to dashboard Cite

show abstract

“…Changes in fine frPOM-C were small by comparison and not found to be significant. The more decomposed state of this C pool (Six et al, 1998), implied by the more fragmented state (Guggenberger et al, 1994) and lower C:N ratios (Table S1) suggests that shifts may be due to reduced turnover from the cessation of tillage-induced disturbance (Kisselle et al, 2001) and not from recent root-derived SOM inputs.…”

Section: Influences On Pom-c Poolsmentioning

confidence: 99%

Factors influencing soil aggregation and particulate organic matter responses to bioenergy crops across a topographic gradient

et al. 2015

View full text Add to dashboard Cite

Bioenergy crops have the potential to enhance soil carbon (C) pools fromincreased aggregation and the physical protection of organicmatter; however, our understanding of the variation in these processes over heterogeneous landscapes is limited. In particular, little is known about the relative importance of soil properties and root characteristics for the physical protection of particulate organic matter (POM). We studied short-term (3-year) changes in aggregation and POM-C pools under three cropping systems (switchgrass, a triticale/sorghumdouble crop, continuous corn) replicated across five landscape positions along a topographic gradient in Iowa, USA.We isolated POMassociated with three aggregate fractions (N2mm, 0.25-2mm, and 0.053-0.25mm) to determine the relative influence of ten soil and three root properties. Aggregation increased in all cropping systems andwas greatest under switchgrass; however cropping systemeffectswere not consistent among positions. Total soil organic C stocks did not change, but Cwithin both physically protected (iPOM-C) and unprotected (frPOM) C pools increased. Shifts in iPOM-C were concurrently influenced by soil properties and root traits. Soil texture had the strongest influence (65% relative importance), with finer-textured soils showing greater gains in total iPOM-C, while greater root biomass influenced (35% relative importance) accrual of total iPOM-C. Aggregate fractions varied in their iPOM-C response to soil and root variables, however individual pools similarly showed the importance of soil texture and root biomass and annual root productivity (BNPP). Changes in frPOM-C were strongly correlated with BNPP. Our data suggest that macroaggregate formation drives short-term responses of POM, which are influenced by both soil and root system properties. Crops that maximize root biomass and BNPP will lead to the largest increases in protected soil C stocks. However, C storage rates will vary across landscapes according to soil conditions, with texture as the primary influence. RightsWorks produced by employees of the U.S. Government as part of their official duties are not copyrighted within the U.S. The content of this document is not copyrighted. Bioenergy crops have the potential to enhance soil carbon (C) pools from increased aggregation and the physical protection of organic matter; however, our understanding of the variation in these processes over heterogeneous landscapes is limited. In particular, little is known about the relative importance of soil properties and root characteristics for the physical protection of particulate organic matter (POM). We studied short-term (3-year) changes in aggregation and POM-C pools under three cropping systems (switchgrass, a triticale/sorghum double crop, continuous corn) replicated across five landscape positions along a topographic gradient in Iowa, USA. We isolated POM associated with three aggregate fractions (N 2 mm, 0.25-2 mm, and 0.053-0.25 mm) to determine the relative influence of ten soil and three root properti...

show abstract

“…In addition to the C added by the cover crops, the total amount of C added to each plot was estimated assuming that the harvest index for grain crops (the ratio of harvested grain to the total aboveground biological yield) is approximately 50% (Unkovich et al, 2010), i.e., for each megagram of grain yield, 1 Mg of shoot dry matter is produced, and assuming that the shoot/root ratio in soils for cereal crops is 30% (Balesdent and Balabane, 1996;Bolinder et al, 1997;Kisselle et al, 2001). Based on these assumptions and the total grain production data (Table 1), it can be estimated that 4.4 to 125 Mg ha −1 of crop residues (leaves, stems, and roots) was added to the soil during the 12 or 17 yr since the beginning of the experiments.…”

Section: Soil Organic Carbon and Relative Cumulative Yieldmentioning

confidence: 99%