2019 SWCS International Annual Conference July 28-31, 2019 Pittsburgh, Pennsylvania

1. A plot study of the impact of the
water-induced channel on tillage
translocation
Speaker: Fangzhou Zheng
Sheng Li
David Lobb
74th SWCS International Annual Conference
Pittsburgh, USA
1

2. Outline
• Background
• Questions
• Materials and methods
– Field site
– Experiment
• Results and discussion
• Summary
2

3. Tillage Translocation
• Tillage operation
– Preparing seedbed
– Harvest
– Weed control
• The resultant
displacement of soil
by tillage operation
• Affected by landscape
3

4. Water Erosion
• Forms of water erosion
– Sheet/interrill
– Rill
– Gully
• Water eroded channels
– Major source of sediment
– Major pathway for
transportation
– Soil surface geometry
alteration
4

5. Water Erosion
• Forms of water erosion
– Sheet/interrill
– Rill
– Gully
• Water eroded channels
– Major source of sediment
– Major pathway for
transportation
– Soil surface geometry
alteration
5

6. Questions
• Will the Existence of Channel Affect Tillage
Translocation?
• How does it Affect?
6

7. Field Site
• Location: FRDC,
Fredericton
• Up & Down Plot
– ~10% slope
• Contour Plot
– ~3% slope
7

8. Treatments
• Channel Treatment
– No Channel (NC)
– Small Channel (10 cm deep by 10 cm wide, C10)
– Big Channel (20 cm deep by 20 cm wide, C20)
• Tillage Direction Treatment
– Downslope (DT)
– Contour (CT)
– Upslope (UT)
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9. 9
C0
CT
C10
CT
C20
CT
C0
DT
C10
DT
C20
DT
C0
UT
C10
UT
C20
UT

10. Point Tracer
• Step 1: Plot setup
– Tracer: 1 cm3 colored cement
– Grid pattern
• Step 2: Tillage operation
• Step 3: Tracer collection
– 10 cm by 10 cm resolution
• Step 4: Tracer translocation calculation
– Location before and after tillage
– Forward & Lateral
10

11. Point Tracer
• Step 1: Plot setup
– Tracer: 1 cm3 colored cement
– Grid pattern
• Step 2: Tillage operation
• Step 3: Tracer collection
– 10 cm by 10 cm resolution
• Step 4: Tracer translocation calculation
– Location before and after tillage
– Forward & Lateral
11

12. Point Tracer
• Step 1: Plot setup
– Tracer: 1 cm3 colored cement
– Grid pattern
• Step 2: Tillage operation
• Step 3: Tracer collection
– 10 cm by 10 cm resolution
• Step 4: Tracer translocation calculation
– Location before and after tillage
– Forward & Lateral
12
2 m
2 m

13. Point Tracer
• Step 1: Plot setup
– Tracer: 1 cm3 colored cement
– Grid pattern
• Step 2: Tillage operation
• Step 3: Tracer collection
– 10 cm by 10 cm resolution
• Step 4: Tracer translocation calculation
– Location before and after tillage
– Forward & Lateral
13
Final
location
(X1,Y1)
Original
location
(X0, Y0)
Forward Movement: Y1-Y0
Lateral Movement: X1-X0

14. Overall Forward Movement
14
0
5
10
15
20
25
30
Downslope Contour Upslope
Translocation(cm)
No channel 10cm channel 20cm channel
• Tillage Direction: DT > CT > UT
• Channel size:
• DT
• Movement decreases with larger channel
• Soil falling into channel
• CT
• Movement increases with larger channel
• Less energy consumed through the channel area

15. Overall Lateral Movement
15
• Movement increases with channel size
• Soil falling into the channel
0
2
4
6
8
10
12
14
16
Downslope Contour Upslope
Absolutetranslocation(cm)
No channel 10cm channel 20cm channel

16. Overall Lateral Movement
16
0
2
4
6
8
10
12
14
16
Downslope Contour Upslope
Absolutetranslocation(cm)
No channel 10cm channel 20cm channel

17. Results and discussion
17
Channel
Region 1 Region 2 Region 3Channel
32 cm
69 cm
32 cm
20 cm40 cm 40 cm
30.6%
overlap
11 cm
25 cm

18. Downslope Forward
18
Channel
Region 1 Region 2 Region 3
0
5
10
15
20
25
30
Region 1 Region 2 Region 3
Translocation(cm)
• Forward Movement
• Shorter movement near channel (Region 2)

19. Downslope Lateral
19
Channel
Region 1 Region 2 Region 3
• Lateral Movement
• Longest movement among three regions (Region 2)
0
5
10
15
20
25
Region 1 Region 2 Region 3
Absolutetranslocation(cm)

20. 0
5
10
15
20
25
30
Region 1 Region 2 Region 3
Translocation(cm)
Upslope Forward
20
• Forward Movement
• Except for the C20, shorter movement near channel (Region 2)
Channel
Region 1 Region 2 Region 3

21. Upslope Lateral
21
• Lateral Movement
• Longest movement among three regions (Region 2)
Channel
Region 1 Region 2 Region 3
0
5
10
15
20
25
Region 1 Region 2 Region 3
Absolutetranslocation(cm)

22. Summary
• The existence of a channel has an impact on
the soil translocation
• For downslope tillage, forward movement is
shorter with larger channel size
• For both upslope and downslope tillage, a
channel can reduce forward movement and
promote lateral movement
22

23. Acknowledgement
• Funding
– Agriculture and Agri-Food
Canada
– University of Manitoba
• Assisting for field work
– Megan Betts
– Tegan Smith
– Zisheng Xing
– Joyce Wang
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