Table 4. Survival, sprouts per cutting planted, ground line diameter (GLD), diameter at breast height, and total height (THT) by clone, location,
and year with the CW cropping system at each study site in the Lower Mississippi Alluvial Valley.
SREC
Year
Age
2009
2010
2011
2012
1
2
3
4
Year
Age
2009
2010
2011
2012
1
2
3
4
Year
Age
2009
2010
2011
2012
1
2
3
4
ST-66
Avg. # GLD
Survival
Sprouts (cm)
73%
1.4
1.2
79%
1.2
4.0
78%
1.1
5.6
78%
1.0
6.4
ST-66
Avg. # GLD
Survival
Sprouts (cm)
87%
1.2
1.3
68%
1.1
2.4
63%
1.1
3.8
63%
1.1
5.1
ST-66
Avg. # GLD
Survival
Sprouts (cm)
79%
1.3
0.7
36%
1.2
1.4
28%
1.1
2.7
28%
1.1
4.1
DBH
(cm)
--2.0
3.0
3.6
DBH
(cm)
--0.4
1.0
1.9
DBH
(cm)
--0.4
1.3
1.9
S7C20
Avg. # GLD
THT Survival
Sprouts (cm)
95
90%
1.5
1.4
344
81%
1.3
4.0
432
81%
1.1
5.3
520
80%
1.0
6.5
PTBES
S7C20
THT
Avg. # GLD
Survival
(cm)
Sprouts (cm)
92
89%
1.3
1.3
151
67%
1.2
2.4
202
64%
1.1
4.0
312
63%
1.1
5.8
SF
S7C20
THT
Avg. # GLD
Survival
(cm)
Sprouts (cm)
73
74%
1.4
0.7
133
36%
1.3
1.7
212
31%
1.0
3.1
368
31%
0.6
2.5
DBH
(cm)
--1.9
3.0
3.7
DBH
(cm)
--0.5
1.2
2.4
DBH
(cm)
--0.5
1.3
1.4
THT
(cm)
95
335
432
525
MIXED
Avg. # GLD
Survival
Sprouts (cm)
84%
1.5
1.4
86%
1.3
4.2
86%
1.1
5.6
86%
1.0
6.5
DBH
(cm)
--2.0
3.2
3.8
THT
(cm)
101
337
432
521
THT
(cm)
88
141
212
327
MIXED
Avg. # GLD
Survival
Sprouts (cm)
84%
1.3
1.4
67%
1.2
2.5
64%
1.2
3.9
64%
1.3
5.1
DBH
(cm)
--0.4
0.9
1.9
THT
(cm)
95
148
196
297
THT
(cm)
68
151
236
227
MIXED
Avg. # GLD
Survival
Sprouts (cm)
75%
1.3
0.9
40%
1.2
1.5
31%
1.0
3.2
31%
1.0
4.5
DBH
(cm)
--0.5
1.3
2.6
THT
(cm)
84
143
249
450
Table 5. Percent biomass components for cottonwood trees in the middle of their fourth growing season at three study sites in the Lower
Mississippi Alluvial Valley.
Study Site
SREC
Clone
S7C20
ST66
Mixed
Avg for SREC
PTBES
Avg. for SF
Percent OD Aboveground
Woody Biomass
Bole
Branches
68%
32%
71%
29%
70%
30%
70%
30%
S7C20
ST66
Mixed
37%
39%
37%
38%
33%
32%
30%
32%
31%
29%
33%
31%
57%
60%
59%
58%
43%
40%
41%
42%
S7C20
ST66
Mixed
48%
48%
51%
49%
23%
21%
21%
22%
29%
31%
28%
29%
70%
73%
73%
72%
30%
27%
27%
28%
Avg for PTBES
SF
Percent Green Aboveground
Components
Bole
Branches
Leaves
51%
27%
22%
54%
26%
20%
52%
27%
21%
52%
27%
21%
Table 6. Average and maximum oven dry aboveground biomass for four-year old cottonwoods grown in the CW treatment at each study site in
the Lower Mississippi Alluvial Valley, reported in short tons/acre and kg/ha.
Study Site
SREC
PTBES
SF
Study Site
SREC
PTBES
SF
ST-66
4.7
1.2
0.9
Mean (tons/acre)
S7C20
5.0
1.9
1.2
Mixed
5.9
1.3
1.4
ST-66
10,471
2,603
2,001
Mean (kg/ha)
S7C20
11,285
4,247
2,659
Mixed
13,255
2,937
3,047
ST-66
9.8
3.8
2.5
Maximum (tons/acre)
S7C20
9.1
5.1
3.1
Mixed
9.3
4.5
4.0
ST-66
22,085
8,444
5,268
Maximum (kg/ha)
S7C20
20,347
11,352
6,895
Mixed
20,828
10,135
8,963
Table 7. Average annual oven dry aboveground biomass switchgrass grown in the CW treatment at each study site in the Lower Mississippi
Alluvial Valley for years 2 through 4.
Calendar Year
2010
2011
2012
SREC
N/A
N/A
N/A
OD kg/ha
PTBES
4,335
14,168
8,391
SF
3,221
6,960
13,388
Table 8. Average annual oven dry (OD) biomass crop production (kg/ha) at each of the three study sites in the Lower Mississippi Alluvial Valley.
Years 2009, 2011, and 2012 are soybean, year 2010 is grain sorghum.
Calendar year
2009
(soybeans)
2010
(grain sorghum)
2011
(soybeans)
2012
(soybeans)
Study Site
SREC
PTBES
SF
SREC
PTBES
SF
SREC
PTBES
SF
SREC
PTBES
SF
Total
1,805
3,769
3,222
14,771
9,696
15,677
4,360
3,616
1,684
3,421
4,432
6,097
OD kg/ha
Grain
605
2,045
161
3,631
871
273
1,713
1,803
336
1,113
1,861
2,273
Residue
1,200
1,725
3,061
11,139
8,824
15,404
2,647
1,814
1,348
2,308
2,571
3,824
Table 9. Cumulative cottonwood, switchgrass, and grain seed and residue biomass production (oven dry kg/ha) at three study sites in the Lower
Mississippi Alluvial Valley over the 2009-2012 growing seasons. Switchgrass average production is for three years (2010-2012).
SREC
Cottonwood
(average of
all varieties)
11,670
PTBES
3,262
26,894
21,513
6,579
14,934
SF
2,569
23,569
26,679
3,042
23,636
SREC
2,918
---
6,089
1,765
4,323
PTBES
816
8,965
5,378
1,645
3,733
SF
642
7,856
6,670
761
5,909
Study site
Total
Average
Control
Switchgrass
Total
Grain seed
Residue
---
24,356
7,062
17,294