Labile soil carbon pools in subtropical forest and agricultural ecosystems as influenced by management practices and vegetation types · Knowledge Library

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Labile soil carbon pools in subtropical forest and agricultural ecosystems as influenced by management practices and vegetation types · Knowledge Library

total organic C

↑ 1= 35

increase
no-tillage (NT) vs. conventional tillage (CT)significant · 0–5 cm · February1992 · Horseshoe Bend Experimental Area (HSB) · HSB mainplots
Numbers
- treatment 23.8 vs. control 12.7 mg C g-1 soil (+87.4 %)
Source · p. 5
“In the HSB mainplots, organic C and N in the CT soil were significantly lower than in the NT soil after 14 yr of continuous treatment.”
no effect
no-tillage (NT) vs. conventional tillage (CT)not significant · 5–15 cm · February1992 · Horseshoe Bend Experimental Area (HSB) · HSB mainplots deep shared a; depth qualification of surface result
Numbers
- treatment 8 vs. control 8.7 mg C g-1 soil (-8.046 %)
Source · p. 5
“CT 12.7b 8.7a 0.94b 0.80a 13.54a 10.89a NT 23.8a 8.0a 2.03a 0.75a 11.74b 10.58a”
no effect
no-tillage (NT) vs. conventional tillage (CT)not significant · 0–15 cm · November1991 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · HSB subplots and Griffin, short term; all a
Numbers
- treatment 13.1 vs. control 8.3 mg C g-1 soil (+57.83 %) · 0–5 cm · HSBsub
- treatment 4.6 vs. control 4 mg C g-1 soil (+15 %) · 5–15 cm · HSBsub
- treatment 34.1 vs. control 23.9 mg C g-1 soil (+42.68 %) · 0–5 cm · Griffin
- treatment 21.4 vs. control 21.5 mg C g-1 soil (-0.4651 %) · 5–15 cm · Griffin
Source · p. 5
“Organic C and N in the CT soils were not significantly different from those in their respective fescue or NT soils at the HSB subplots and at Griffin over the short term.”
increase
forest soils vs. agricultural soilssignificance not stated · 0–15 cm · November1991; February1992 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · Watkinsville sandy soil (WKS) · Watkinsville clayey soil (WKC) · Coweeta Watershed 1 · Coweeta Watershed 27 · Coweeta Watershed 55 · Descriptive regional forest/agriculture contrast; not randomized or a pooled pairwise test
Source · p. 4
“Total organic C of forest soils was 2-25 fold”
Source · p. 4
“higher than that of the agricultural soils (Table 2).”
no effect
fescue sods vs. conventional tillage (CT)not significant · 0–15 cm · November1991 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · Fescue/CT; HSBsub and Griffin; all a/a
Numbers
- treatment 14.7 vs. control 8.3 mg C g-1 soil (+77.11 %) · 0–5 cm · HSBsub
- treatment 5 vs. control 4 mg C g-1 soil (+25 %) · 5–15 cm · HSBsub
- treatment 30.3 vs. control 23.9 mg C g-1 soil (+26.78 %) · 0–5 cm · Griffin
- treatment 19.5 vs. control 21.5 mg C g-1 soil (-9.302 %) · 5–15 cm · Griffin
Source · p. 5
“Organic C and N in the CT soils were not significantly different from those in their respective fescue or NT soils at the HSB subplots and at Griffin over the short term.”

soil carbohydrates

↑ 1= 35

increase
no-tillage (NT) vs. conventional tillage (CT)significant · 0–5 cm · February1992 · Horseshoe Bend Experimental Area (HSB) · HSBmain
Numbers
- treatment 752 vs. control 364 µg carbohydrates g-1 soil (+106.6 %)
Source · p. 5
“In the HSB mainplots, carbohydrates were significantly lower in conventional (CT) soils”
Source · p. 6
“CT 364b 349a 345b 226a NT 752a 329a 719a 208a”
no effect
no-tillage (NT) vs. conventional tillage (CT)not significant · 5–15 cm · February1992 · Horseshoe Bend Experimental Area (HSB) · HSBmain; deep a/a; qualification of surface result
Numbers
- treatment 329 vs. control 349 µg carbohydrates g-1 soil (-5.731 %)
Source · p. 6
“CT 364b 349a 345b 226a NT 752a 329a 719a 208a”
no effect
no-tillage (NT) vs. conventional tillage (CT)not significant · 0–5 cm · November1991 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · HSBsub and Griffin; shared a, explicit short-term null. Deep Griffin table-only significant pair excluded against prose.
Numbers
- treatment 782 vs. control 507 µg carbohydrates g-1 soil (+54.24 %) · HSBsub
- treatment 2,225 vs. control 1,450 µg carbohydrates g-1 soil (+53.45 %) · Griffin
Source · p. 5
“no significant short-term (2 yr) effects of management practices on soil carbohydrates were observed at the HSB subplots.”
increase
forest soils vs. agricultural soilssignificance not stated · 0–15 cm · November1991; February1992 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · Watkinsville sandy soil (WKS) · Watkinsville clayey soil (WKC) · Coweeta Watershed 27 · Forest carbohydrates measured only at WS27; stated regional generalization; no cross-site pair test in Table3
Source · p. 5
“Soil carbohydrates were significantly different between forest and agricultural soils”
no effect
fescue sods vs. conventional tillage (CT)not significant · 0–15 cm · November 1991 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · Short-term fescue sod versus CT at HSB subplots and Griffin. Both sampled layers share LSD letters: HSB a/a at both depths; Griffin a/a at 0-5 cm and ab/b at 5-15 cm. Not a claim about long-term HSB mainplots. Table reports three or four field replicates without assigning n to each group, so n remains unset.
Numbers
- treatment 508 vs. control 507 µg carbohydrates g-1 soil (+0.1972 %) · 0–5 cm · November 1991 · HSB subplots; fescue a versus CT a
- treatment 290 vs. control 240 µg carbohydrates g-1 soil (+20.83 %) · 5–15 cm · November 1991 · HSB subplots; fescue a versus CT a
- treatment 1,546 vs. control 1,450 µg carbohydrates g-1 soil (+6.621 %) · 0–5 cm · November 1991 · Griffin; fescue a versus CT a
- treatment 946 vs. control 897 µg carbohydrates g-1 soil (+5.463 %) · 5–15 cm · November 1991 · Griffin; fescue ab versus CT b
Source · p. 5
“no significant short-term (2 yr) effects of management practices on soil carbohydrates were observed at the HSB subplots.”
Source · p. 6
“CT 507a 240a 248b 213a”
Source · p. 6
“Fescue 508a 290a 721a 203a”
Source · p. 6

total N

↑ 1= 34

increase
no-tillage (NT) vs. conventional tillage (CT)significant · 0–5 cm · February1992 · Horseshoe Bend Experimental Area (HSB) · HSB mainplots
Numbers
- treatment 2.03 vs. control 0.94 mg N g-1 soil (+116 %)
Source · p. 5
“In the HSB mainplots, organic C and N in the CT soil were significantly lower than in the NT soil after 14 yr of continuous treatment.”
no effect
no-tillage (NT) vs. conventional tillage (CT)not significant · 5–15 cm · February1992 · Horseshoe Bend Experimental Area (HSB) · HSB mainplots deep shared a
Numbers
- treatment 0.75 vs. control 0.8 mg N g-1 soil (-6.25 %)
Source · p. 5
“CT 12.7b 8.7a 0.94b 0.80a 13.54a 10.89a NT 23.8a 8.0a 2.03a 0.75a 11.74b 10.58a”
no effect
no-tillage (NT) vs. conventional tillage (CT)not significant · 0–15 cm · November1991 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · HSBsub and Griffin
Numbers
- treatment 1.15 vs. control 0.75 mg N g-1 soil (+53.33 %) · 0–5 cm · HSBsub
- treatment 0.48 vs. control 0.43 mg N g-1 soil (+11.63 %) · 5–15 cm · HSBsub
- treatment 2.47 vs. control 1.54 mg N g-1 soil (+60.39 %) · 0–5 cm · Griffin
- treatment 1.43 vs. control 1.56 mg N g-1 soil (-8.333 %) · 5–15 cm · Griffin
Source · p. 5
“Organic C and N in the CT soils were not significantly different from those in their respective fescue or NT soils at the HSB subplots and at Griffin over the short term.”
no effect
fescue sods vs. conventional tillage (CT)not significant · 0–15 cm · November1991 · Horseshoe Bend Experimental Area (HSB) · Bledsoe Farm (Griffin) · Fescue/CT; HSBsub and Griffin; all a/a
Numbers
- treatment 1.44 vs. control 0.75 mg N g-1 soil (+92 %) · 0–5 cm · HSBsub
- treatment 0.54 vs. control 0.43 mg N g-1 soil (+25.58 %) · 5–15 cm · HSBsub
- treatment 2.16 vs. control 1.54 mg N g-1 soil (+40.26 %) · 0–5 cm · Griffin
- treatment 1.24 vs. control 1.56 mg N g-1 soil (-20.51 %) · 5–15 cm · Griffin
Source · p. 5
“Organic C and N in the CT soils were not significantly different from those in their respective fescue or NT soils at the HSB subplots and at Griffin over the short term.”

Sites

Horseshoe Bend Experimental Area (HSB)

Location: Athens, Georgia
Land use: agricultural soilsArable land, fescue sodsPastures and managed grassland

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
HSB soil (characterisation depth unstated)	sandy clay loam (text); loamy sand (Table1)	21 %	–	–	–

Bledsoe Farm (Griffin)

Location: Griffin, Georgia
Land use: agricultural soilsArable land, fescue sodsPastures and managed grassland

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
Griffin soil (depth unstated)	sandy loam	–	–	–	–

Watkinsville sandy soil (WKS)

Location: Dawson field near Watkinsville, Georgia
Land use: agricultural soilsArable land

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
WKS soil (depth unstated)	sandy loam	–	–	–	–

Watkinsville clayey soil (WKC)

Location: Dawson field near Watkinsville, Georgia
Land use: agricultural soilsArable land

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
WKC soil (depth unstated)	sandy clay loam	–	–	–	–

Coweeta Watershed 1

Location: Coweeta Hydrological Lab., western North Carolina (laboratory coordinates)35.05° N, 83.42° W
Land use: White pinesConiferous forest

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
WS1 soil (depth unstated)	sandy loam	–	–	–	–

Coweeta Watershed 27

Location: Coweeta Hydrological Lab., western North Carolina (laboratory coordinates)35.05° N, 83.42° W
Land use: northern hardwood dominated by red oakBroad-leaved forest

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
WS27 soil (depth unstated)	sandy loam	–	–	–	–

Coweeta Watershed 55

Location: Coweeta Hydrological Lab., western North Carolina (laboratory coordinates)35.05° N, 83.42° W
Land use: Rhododendron maximum and Quercus prinus / Liriodendron tulipiferaBroad-leaved forest

Soil layers
Depth	Texture	Clay	pH	Organic C	Bulk density
WS55 soil (depth unstated)	sandy loam	–	5.5	–	–