Plant
Family

Functional
Type

Fallow

Grazing

Groundnut

3.3 (0.8)
(a)
40.2 (4.2)
12.9 (3.2)
(a)

3.5 (0.9)
(a)
40.8 (3.9)
12.5 (3.3)
(a)

4.5 (NA)
34.7 (NA)
7.7 (NA)

NP

NP

3.4 (0.7)
42.0 (2.0)
13.0 (2.7)

3.5 (0.7)
41.2 (3.6)
12.1 (2.6)

NP

Millet

F
Value

P Value

All Plants
%N
%C
C:N Ratio
Poaceae
(millet only)
%N
%C
C:N Ratio
Poaceae
(excluding millet)
%N
%C
C:N Ratio
Fabaceae
(groundnut only)
%N
%C
C:N Ratio
Fabaceae
(excluding
groundnut)
%N
%C
C:N Ratio
Combretaceae
%N
%C
C:N Ratio
Commelinaceae
%N
%C
C:N Ratio
Convolvulaceae
%N
%C
C:N Ratio
Cyperaceae
%N
%C
C:N Ratio
Malvaceae
%N
%C
C:N Ratio
Rubiaceae
%N
%C
C:N Ratio
Unknown forb
sprout
%N
%C
C:N Ratio

4.2 (1.2) (b)

3.5 (0.7)
(a)
40.3 (3.4)
12.0 (2.8)
(a)

8.1

**0.004

0.1

1.0

9.6

**0.002

3.4 (0.7)
42.3 (2.1)
13.2 (3.1)

3.8
13.0
3.5

0.1
0.002
0.1

3.4 (0.8)
39.8 (0.8)
12.4 (4.4)

3.3 (0.4)
42.2 (2.7)
13.1 (2.0)

0.3
0.6
0.3

0.9
0.6
0.8

NP

4.9 (1.4)
42.5 (2.6)
9.2 (2.4)

4.1 (0.5)
42.3 (0.2)
10.3 (1.1)

0.2
0.0
0.0

0.7
0.9
0.8

3.4 (0.6)
42.3 (1.1)
12.6 (2.1)

3.4 (1.1)
42.1 (0.9)
13.6 (4.0)

4.3 (0.7)
40.7 (0.7)
9.8 (2.2)

2.7
41.8
15.3

2.1
0.4
1.8

0.2
0.7
0.2

3.3 (0.0)
47.0 (0.4)
14.1 (0.3)

4.5 (1.8)
43.2 (6.9)
11.2 (6.6)

3.6 (0.4)
46.1 (0.5)
12.8 (1.7)

NP
NP
NP

0.6
0.4
0.2

0.6
0.7
0.8

3.2 (0.2)
39.4 (2.3)
12.2 (0.5)

3.7 (0.6)
37.1 (3.1)
10.2 (1.7)

3.7 (0.7)
37.4 (2.2)
10.4 (2.4)

NP
NP
NP

3.8
2.2
5.5

*0.03
0.1
**0.01

3.2 (0.7)
35.9 (3.8)
11.7 (3.0)

3.1 (1.0)
35.5 (3.8)
12.6 (4.4)

3.6 (0.2)
36.7 (2.8)
10.3 (0.8)

3.7 (0.7)
37.1 (3.2)
10.3 (2.1)

1.7
0.4
1.3

0.2
0.8
0.3

2.4 (0.3)
43.6 (2.0)
18.6 (2.0)

NP

3.2 (0.1)
43.1 (0.8)
13.7 (0.8)

2.9 (0.3)
43.4 (2.0)
14.9 (2.0)

11.4
0.0
6.5

*0.04
1.0
0.1

6.1
42.4
6.9

NP

NP

NP

2.6 (1.1)
35.1 (5.2)
14.7 (5.2)

3.5 (0.2)
37.2 (4.0)
10.8 (0.7)

3.4 (0.1)
32.2 (2.8)
9.5 (1.2)

3.1 (0.4)
35.4 (4.3)
11.4 (0.1)

34.3
0.2
43.1

**0.01
0.9
0.0

NP

NP

3.8 (0.1)
40.4 (0.0)
10.8 (0.4)

3.4
41.9
12.2

40.1 (4.1)
10.0 (2.2) (b)

Grass

Grass

Legume

Legume

Shrub

Forb

Forb

Sedge

Forb

Forb

Forb

1

Supplemental Table 1: Plant nutrient variation by plant family across land use type; values
indicate mean (SE). Letters show post hoc significant differences from Tukey HSD
comparisons following ANOVAs. Not present in field (NP).

2

Supplemental Table 2: Correlation between grasshopper species, plant N content and
plant C:N ratio. Spearman's rank correlation tests were used for all species besides O.
senegalensis where we used a Pearson's correlation test.

Plant N
r R2

Plant C:N
(p-value)

Plant
C:N
r

Species

Feeder

Plant N
(p-value)

Acorypha spp

Mixed

1

0

1

0

Acrida bicolor

Mixed/
Graminivorous

0.4

-0.2

0.2

0.4

Acrotylus spp

Mixed

0.005**

-0.9

0.008**

0.8

Catantops
stramineus

Mixed

Insufficient n

Chrotogonus
senegalensis

Mixed

0.9

-0.04

0.7

0.1

Cryptocatantops
haemorrhoidalis

Mixed/NonGraminivorous

Insufficient n

-

-

-

Diabolocatantops
axillaris

Mixed

Insufficient n

-

-

-

Oedaleus
senegalensis

Graminivorous

0.045*

-0.4

0.003**

0.6

Ornithacris
cavroisi

Mixed

Insufficient n

-

-

-

Pyrgomorpha
cognata

Mixed

Insufficient n

-

-

-

Unknown nymph

NA

Insufficient n

-

-

-

3

Appendix A. Results of mixed linear regression model selection
Model Table 1:
Soil Variable Models
TotalN ~ SOM + BD + pH + Soil Moisture +
EC + Dung Cover + Rock Cover)
TotalN ~ Live Vegetation Cover + BD + pH +
Soil Moisture + EC + Dung Cover + Rock
Cover)
TotalN ~ SOM + BD + pH + Soil Moisture +
Dung Cover + Rock Cover)
TotalN ~ SOM + BD + EC + pH + Dung
Cover + Rock Cover)
TotalN ~ SOM + BD + pH + Soil Moisture +
Dung Cover)

AIC

AICc

dAICc

Weight
[AICc]

115.27

129.02

3.55

0.14

117.59

131.34

5.88

0.04

133.42

144.00

18.19

0

114.88

125.47

0

0.82

135.66

143.66

18.19

0

Model Table 2:
Farmer Management Variable Models
TotalN~ ResRemoved + Fertilizer Use +
Years Groundnut + Years Fallow + Years
Millet + Years Beans + Cover Crop)
TotalN~ ResRemoved + Fertilizer Use +
Years Groundnut + Years Fallow +Years
Millet + Cover Crop)
TotalN~ ResRemoved + Fertilizer Use +
Years Groundnut + Years Fallow + Years
Millet + Years Beans)
TotalN~ ResRemoved + Fertilizer Use +
Years Fallow + Years Millet + Cover Crop)
TotalN~ ResRemoved + Fertilizer Use +
Years Groundnut + Years Fallow + Years
Beans + Cover Crop)

AIC

AICc

dAICc

Weight
[AICc]

75.26

111.93

7.64

0.01

82.91

108.62

4.33

0.06

78.58

104.29

0.00

0.48

87.56

105.56

1.28

0.26

80.41

106.12

1.83

0.19

Model Table 3:
Plant Soil Variable Models
Non-N fixing Plant N ~ Soil Total N + Crop
Type + Dung Cover + Litter Cover)
Non-N fixing Plant N ~ Soil Total N +
Dung Cover + Litter Cover)
Non-N fixing Plant N ~ Soil Total N + Dung
Cover + Crop Type)
Non-N fixing Plant N ~ Soil Total N + Crop
Type + Litter Cover)
Non-N fixing Plant N ~ Soil Total N + Crop
Type)

AIC

AICc

dAICc

Weight
[AICc]

-10.88

-9.80

14.61

0.00

-24.90

-24.41

0.00

0.53

-17.45

-16.59

7.82

0.01

-18.19

-17.33

7.08

0.02

-24.72

-24.06

0.35

0.44

4

Model Table 4:
Locust Plant Soil Variable Models
O. senegalensis Abundance ~ Plant Species N
+ Soil Total N + Live Vegetation Cover +
rock + dung + litter + Crop + Years Fallow)
O. senegalensis Abundance ~ Plant Species N
+ Soil Total N + Live Vegetation Cover +
rock + dung + litter + Crop)
O. senegalensis Abundance ~ Plant Species
N + Soil Total N + Live Vegetation Cover +
rock + dung + litter + Years Fallow)
O. senegalensis Abundance ~ Plant Species N
+ Soil Total N + rock + dung + litter + Crop
+ Years Fallow)
O. senegalensis Abundance ~ Plant Species N
+ Soil Total N + Live Vegetation Cover +
rock + dung + Crop + Years Fallow)

AIC

AICc

dAICc

Weight
[AICc]

82.06

115.15

15.81

0.00

78.03

104.03

4.68

0.09

83.63

99.34

0.00

0.89

85.74

111.74

12.39

0.00

81.15

107.15

7.81

0.02

5