16. 16
• Spatial variation?
Concentration(ng/g,dryweightbasis)
0
50
100
150
200
250
300
350
400
Pirlimycin
Sulfamerazine
Tylosin
Chlortetracycline
Days between manure application rain - after rain
0 day
0-5 cm
Surface
Slit
5
15
25
40
0-5 cm
5-20 cm
5 15 25 40
0.0
0.1
0.2
5.0
10.0
5 15 25 40
0.0
0.5
1.0
Surface
Slit
5
15
25
40
0
50
100
150
200
250
300
350
5-20 cm
Surface
Slit
5
15
25
40
3 days 7 days
5 15 25 40
0.0
0.1
0.2
5.0
10.0
5 15 25 40
0.0
0.5
1.0
5 15 25 40
0
2
4
6
8
10
5 15 25 40
0.0
0.1
1.0
2.0
3.0
4.0
distance from the slit (cm)
Subsurface injection
Surface
application
Surface
application
Surface
application
distance from the slit (cm)
Subsurface injection
distance from the slit (cm)
Subsurface injection
CECs in soil
Concentration(ng/g,d.w.)
17. 17
• Temporal change?
Time since rain event (days)
rain 5 14 60 180
Concentrationofchlortetracycline(ng/g,d.w.)
0
50
100
150
200
250
Days between manure application & rain event:
injection slit
Time since rain event (days)
rain 5 14 60 180
Concentrationofchlortetracycline(ng/g,d.w.)
0
10
20
30
40
50
Surface application
0 3 7
Chlortetracycline in soil decreased with time since rain event
18. • Manure subsurface injection concentrates CECs within the
injection slits
Conclusions
• Loss of CECs in surface runoff occurred during the 1st rain
event after manure application
• Apply manure at lease 3 days before a major rain event
• Minor horizontal transfer of CECs from the injection slits
• Less CECs left the field with surface runoff when manure is
subsurface injected comparing to surface application
18