landscape influence on soil carbon
DESCRIPTION
69th SWCS International Annual Conference “Making Waves in Conservation: Our Life on Land and Its Impact on Water” July 27-30, 2014 Lombard, ILTRANSCRIPT
Landscape Influence on Soil Carbonand Nutrient Levels
S.D. Logsdon, USDA‐ARS‐NLAE
Background• Nonuniform soil carbon and nutrient loads• Runoff ‐ runon, erosion ‐ deposition within fields• Mean soil loss or gain ~ ± 5 cm in 40 yrs (Schumacher et al., 2005)• Oxidation of soil carbon at well‐drained sites (Dlugoβ et al., 2010)• Better plant growth downslope build up soil C (Landi et al., 2004)• Interaction between organic and inorganic carbon (Lebrón et al., 1996)• Increased denitrification at poorly‐drained sites (Cambardella et al., 1999)• Nitrate leach from low areas (Whetter et al., 2006)• P deposition in depressions (Kaspar et al., 2004)
The purpose of this study was to examine landscape position effect onsoil carbon and nutrient levels.
Methods• One field in Walnut Creek (Hatfield et al. , 1999)• Two fields in South Fork (Tomer et al., 2008)• 30 sites per field, 3 wells per field• LiDAR 1‐m data cleaned up and 10‐m neighborhood used(Logsdon and James, 2014)•Profile description, nutrients and carbon 0‐0.15 and 0.15 ‐0.3 m• Soil texture by feel, sieved sand for coarse‐textured samples• Relation of landscape to soil properties: Mann‐Whitney rank sum test• Sampled fall 2012 (drought)
Two sites were sampled within South Fork and one site within Walnut Creek north.
Site in WalnutCreek north showing twotransects (~115 m long each, 30 locationstotal) and three wells (orange)
First site in South Fork showing twotransects (105 or 120 m long,30 locations total) and three wells (blue).
Second site in SouthFork showing twotransects (~110 m longeach, 30 locationstotal) and three wells (blue).
Methods• One field in Walnut Creek (Hatfield et al. , 1999)• Two fields in South Fork (Tomer et al., 2008)• 30 sites per field, 3 wells per field• LiDAR 1‐m data cleaned up and 10‐m neighborhood used(Logsdon and James, 2014)• Profile description, nutrients and carbon 0‐0.15 and 0.15 ‐0.3 m• Soil texture by feel, sieved sand for coarse‐textured samples• Relation of landscape to soil properties: Mann‐Whitney rank sum test• Sampled fall 2012 (drought)
Lidar 1‐m data:• curvature not based onlocal 1‐m neighborhood• data not averaged over larger grid size • instead each point analyzedusing larger range• maximum range 10 m• sliding range for highervariability
-10 -5 0 5 10
-10
-5
0
5
10
Methods• One field in Walnut Creek (Hatfield et al. , 1999)• Two fields in South Fork (Tomer et al., 2008)• 30 sites per field, 3 wells per field• LiDAR 1‐m data cleaned up and 10‐m neighborhood used(Logsdon and James, 2014)• Profile description, nutrients and carbon 0‐0.15 and 0.15 ‐0.3 m• Soil texture by feel, sieved sand for coarse‐textured samples• Relation of landscape to soil properties: Mann‐Whitney rank sum test• Sampled fall 2012 (drought)
Property Relativeelevation < 1.8 m
Relativeelevation ≥ 1.8 m
Mollic depth (m) 0.60a 0.41b
Depth to carbonates (m) 1.04a 0.94a
Organic carbon 0‐0.15 m g/100g
2.79a 1.63b
Organic carbon 0.15‐0.3 m g/100g
2.42a 1.31b
Total nitrogen 0‐0.15 m g/100g
0.23a 0.15b
Total nitrogen 0.15‐0.3 m g/100g
0.18a 0.13b
Carbonate depth does not include sites with carbonate at the soil surface.Means within a row followed by the same letter are not significantly different at p = 0.05.
Results. Table 1. Influence of relative elevation on soil properties.
Property Slope < 2.8 % Slope ≥ 2.8 %
Mollic depth (m) 0.74a 0.41b
Depth to carbonates (m) 1.18a 0.95b
Organic carbon 0‐0.15 m g/100g
3.28a 1.95b
Organic carbon 0.15‐0.3 m g/100g
1.95a 1.41b
Total nitrogen 0‐0.15 m g/100g
0.27a 0.20b
Total nitrogen 0.15‐0.3 m g/100g
0.21a 0.16b
Carbonate depth does not include sites with carbonate at the soil surface.Means within a row followed by the same letter are not significantly different at p = 0.05.
Table 2. Influence of slope on soil properties.
Property Convex≤‐0.08/m
Linear Concave≥0.08/m
Mollic depth (m) 0.15b 0.51a 0.62a
Depth to carbonates (m) 0.90b 0.92b 1.18a
Organic carbon 0‐0.15 m g/100g
1.79b 2.35a 2.34a
Organic carbon 0.15‐0.3 m g/100g
1.08b 1.77a 1.99a
Total nitrogen0‐0.15 m g/100g
0.14b 0.21a 0.20a
Total nitrogen 0.15‐0.3 m g/100g
0.11b 0.16a 0.16a
Table 3. Influence of profile curvature on soil properties.
Carbonate depth does not include sites with carbonate at the soil surface.Means within a row followed by the same letter are not significantly different at p = 0.05.
Property Divergent≤‐0.08/m
Linear Convergent≥0.08/m
Mollic depth (m) 0.33b 0.60a 0.88a
Depth to carbonates (m) 0.91b 0.99ab 1.22a
Organic carbon 0‐0.15 m g/100g
1.74b 2.45a 3.10a
Organic carbon 0.15‐0.3 m g/100g
1.31b 1.95a 2.79a
Total nitrogen0‐0.15 m g/100g
0.15b 0.20a 0.26a
Total nitrogen 0.15‐0.3 m g/100g
0.13b 0.16a 0.21a
Table 4. Influence of plan curvature on soil properties.
Carbonate depth does not include sites with carbonate at the soil surface.Means within a row followed by the same letter are not significantly different at p = 0.05.
Property Relativeelevation < 1.8 m
Relativeelevation ≥ 1.8 m
NO3‐ 0‐0.15 m mg/kg 1.36a 5.2b
NO3‐ 0.15‐0.3 m mg/kg 7.3a 3.1b
NH4+ 0‐0.15 m mg/kg 4.1a 1.5b
NH4+ 0.15‐0.3 m mg/kg 2.5a 1.5b
PO4‐3 0‐0.15 m mg/L 12a 3b
PO4‐3 0.15‐0.3 m mg/L 2a 1b
Only two fields included because of manure application at the other field.Means within a row followed by the same letter are not significantly different at p = 0.05.
Table 5. Influence of relative elevation on soil nutrient levels.
Property Slope < 2.8% Slope ≥ 2.8 %NO3
‐ 0‐0.15 m mg/kg 15.2a 6.3bNO3
‐ 0.15‐0.3 m mg/kg 7.3a 3.4bNH4
+ 0‐0.15 m mg/kg 4.1a 3.2aNH4
+ 0.15‐0.3 m mg/kg 2.5a 1.9aPO4
‐3 0‐0.15 m mg/L 12a 5bPO4
‐3 0.15‐0.3 m mg/L 3a 1b
Table 6. Influence of slope on soil nutrient levels.
Only two fields included because of manure application at the other field.Means within a row followed by the same letter are not significantly different at p = 0.05.
Property Convex≤‐0.08/m
Linear Concave≥0.08/m
NO3‐ 0‐0.15 m mg/kg 4.9b 10.8a 13.6a
NO3‐ 0.15‐0.3 m mg/kg 3.2b 6.6a 6.5a
NH4+ 0‐0.15 m mg/kg 3.2a 4.5a 4.1a
NH4+ 0.15‐0.3 m mg/kg 1.5a 2.6a 2.3a
PO4‐3 0‐0.15 m mg/L 2b 10a 15.5a
PO4‐3 0.15‐0.3 m mg/L 1b 3a 3a
Table 7. Influence of profile curvature on soil nutrient levels.
Only two fields included because of manure application at the other field.Means within a row followed by the same letter are not significantly different at p = 0.05.
Property Divergent≤‐0.08/m
Linear Convergent≥0.08/m
NO3‐ 0‐0.15 m mg/kg 4.9b 10.8a 16.0a
NO3‐ 0.15‐0.3 m mg/kg 3.1c 6.1b 12.4a
NH4+ 0‐0.15 m mg/kg 3.1a 3.8a 3.9a
NH4+ 0.15‐0.3 m mg/kg 1.6b 2.8a 2.1ab
PO4‐3 0‐0.15 m mg/L 2b 12a 21a
PO4‐3 0.15‐0.3 m mg/L 1b 3a 4a
Table 8. Influence of plan curvature on soil nutrient levels.
Only two fields included because of manure application at the other field.Means within a row followed by the same letter are not significantly different at p = 0.05.
Figure 1.Nutrient levels for onetransect in the first field ofSouth Fork where swinemanure had been applied.
Day 2013
160 180 200 220 240 260 280
Nitr
ate
(mg/
kg)
0
10
20
30
40
50
WC1WC2WC32SF12SF22SF31SF11SF21SF3
Figure 2. Nitrate levels in wells from three fields.
Day 2013
120 140 160 180 200 220 240 260
Wat
er ta
ble
elev
atio
n (m
)
345
346
347
348
2SF12SF22SF3
Day 2014
20 40 60 80 100 120 140 160 180
345
346
347
348
Figure 3.Here water table elevationsare shown for the second field in South Fork wherenitrate concentrations remained high when the water table was deep.
Summary• Low slope, concave, linear, converging: higher
organic carbontotal nitrogenNitrate‐Northo phosphate
• Uneven swine manure application: local zones of high nutrient• Nitrate in ground water remained high at some converging sites:
Perhaps subsurface lateral additions or too dry for denitrification