Soil Ammonium and Nitrate Concentrations

Cropping system Year
Depth (cm)
Ammonium (ppm)
Nitrate (ppm)

 

Conv. Corn/Tomato

2003

0
2.39
24.35

15
1.12
10.84

30
0.60
2.43

60
0.50
0.87

100
0.44
0.58

150
0.50
0.76

200
0.51
1.14

250
0.44
1.39

2007

0
1.23
12.28

15
1.07
3.88

30
0.45
0.87

60
0.34
0.38
Conv. Wheat/Tomato

2007

0
0.67
13.66

15
0.35
7.57

30
0.25
2.42

60
0.24
1.02
Irrigated Wheat Control

2007

0
0.72
7.50

15
0.30
2.90

30
0.18
0.95

60
0.13
0.45
Irrigated Wheat/Fallow

2003

0
1.38
17.66

15
0.64
8.81

30
0.63
2.82

60
0.58
1.45

100
0.63
1.30

150
0.54
1.64

200
0.51
2.26

250
0.44
3.04

2007

0
0.66
14.95

15
0.41
5.67

30
0.33
2.47

60
0.28
1.59
Irrigated Wheat/Legume

2007

0
1.02
7.20

15
0.39
10.56

30
0.21
1.57

60
0.21
0.85
Legume/Corn/Tomato

2007

0
1.42
10.98

15
0.84
2.50

30
0.61
0.58

60
0.51
0.28
Organic Corn/Tomato

2003

0
3.51
23.38

15
1.08
8.74

30
0.60
1.90

60
0.48
0.61

100
0.42
0.51

150
0.43
0.67

200
0.50
1.07

250
0.43
1.15

2007

0
1.65
19.84

15
1.02
3.63

30
0.65
0.86

60
0.60
0.38
Rainfed Wheat Control

2003

0
1.14
2.04

15
0.70
2.61

30
0.58
0.76

60
0.58
0.29

100
0.58
0.21

150
0.50
0.25

200
0.46
0.71

250
0.47
1.02
Transitional

2007

0
1.25
29.34

15
0.93
4.99

30
0.46
1.31

60
0.46
0.57