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Li et al. 10.1073/pnas.0704591104. |
Table 4. Biomass and grain yield of maize and faba bean in monoculture and intercropping systems in 4 yr from 2003 to 2006
|
Yields, kg/ha (% increase) |
ANOVA |
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|
Crop |
Cropping system |
2003 |
2004 |
2005 |
2006 |
Variable |
F |
P |
|
|
Grain |
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Maize |
M(C) |
14,635 ± 1,718b (0) |
10,398 ± 1,647b (0) |
15,226 ± 2,191b (0) |
10,992 ± 682b (0) |
C |
54.1 |
<0.0001 |
|
|
M&F(C) |
19,033 ± 703a (30) |
15,268 ± 1,367a (47) |
22,233 ± 1,594a (46) |
19,088 ± 371a (74) |
Y |
25.2 |
<0.0001 |
||
|
M&F(R) |
17,188 ± 1,887ab (17) |
15,275 ± 704a (47) |
21,084 ± 1,288a (38) |
15,906 ± 2,700a (45) |
C·Y |
1.5 |
0.2133 |
||
Faba bean |
F(C) |
3,313 ± 169a (0) |
5,112 ± 204b (0) |
5,737 ± 282a (0) |
3,000 ± 834a (0) |
C |
9.6 |
0.0010 |
|
|
M&F(C) |
3,513 ± 49a (6) |
6,720 ± 400ab (31) |
6,745 ± 1456a (18) |
3,988 ± 804a (33) |
Y |
48.2 |
<0.0001 |
||
|
M&F(R) |
3,414 ± 177a (3) |
8,669 ± 778a (71) |
7,243 ± 563a (26) |
3,539 ± 256a (18) |
C·Y |
2.9 |
0.0308 |
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|
Above-ground biomass |
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Maize |
M(C) |
28,546 ± 2,300c (0) |
23,763 ± 5,460b (0) |
32,286 ± 6,193b (0) |
23,077 ± 1,983b (0) |
C |
53.9 |
<0.0001 |
|
|
M&F(C) |
34,951 ± 545a (22) |
33,734 ± 3,977a (42) |
51,452 ± 3,371a (59) |
39,837 ± 1,550a (73) |
Y |
31.2 |
<0.0001 |
||
|
M&F(R) |
31,749 ± 485b (11) |
33,382 ± 3,415a (40) |
46,777 ± 1,207a (45) |
36,046 ± 4,221a (56) |
C·Y |
3.0 |
0.0254 |
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Faba bean |
F(C) |
7,754 ± 1,091a (0) |
13,300 ± 810b (0) |
12,509 ± 2,015b (0) |
7,954 ± 2,214a (0) |
C |
9.0 |
0.0014 |
|
|
M&F(C) |
8,586 ± 681a (11) |
18,728 ± 1,793a (41) |
12,563 ± 2,917b (0) |
10,759 ± 2,100a (35) |
Y |
64.0 |
<0.0001 |
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|
M&F(R) |
7,695 ± 658a (-1) |
20,805 ± 761a (56) |
15,122 ± 1,993ab (21) |
8,391 ± 1,169a (5) |
C·Y |
4.3 |
0.0053 |
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M(C), continuously cropped maize; F(C), continuously cropped faba bean; F&M(C), faba bean and maize continuously intercropped with the same crop on the same strips of land; and F&M(R), faba bean and maize rotationally intercropped with each crop rotated to the other crop's strips each year. Each treatment had three replicates and all plots received 225 kg/ha nitrogen fertilizer and 40 kg/ha P2O5 fertilizer. % Increase = (M&F-M)/M ´100 or = (M&F-F)/F ´ 100. Values in the same column within the same crop followed by different letters are significantly different by LSD multiple comparisons (P < 0.05). Two-way ANOVA with cropping (C) system and year (Y) as variables, where df is 2 for cropping, 3 for year, and 6 for interactions between cropping and year.
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