| Workshop-seminar, 23-25 May, 2005, MEKARN-CTU |
| Contents |
1Tropical Feed Resources Research and
Development Center, Department of Animal Science,
2Department of Agronomy, Faculty of Agriculture, Khon
Kaen University, Thailand
metha@kku.ac.th
The objectives of these experiments were to investigate the effects of various types of legume intercropping on yield and nutritive value of cassava foliage, and the potential of a long-term harvesting system of cassava foliage. Sixteen plots (4x8 m each) of cassava were randomly allocated according to a RCBD to receive four treatments of legume intercropping (2 rows of legume to every 4 rows of cassava); Control = without intercropping, CP = cowpea (Vigna unguiculata L.) intercropping, ST = with Stylosanthes guianensis, CIAT 184 intercropping; and PC = Phaseolus calcaratus intercropping. In addition, the half-area of each of the four plots of the control group were continuously harvested for cassava foliages in the second year of production.
The results showed that legume intercropping did not affect total DM yield and chemical composition of cassava foliage and root. Total yields of cassava foliage and root in the second year of production were not significantly different from the first year production. Crude protein (CP) content of cassava foliages were not significantly different among first (20.2 %) and second year (24.1 %) of production, but ash content was significantly higher (P<0.05) for second year cassava foliage while both acid and neutral detergent fiber (ADF and NDF) were significantly higher (P<0.05) for cassava foliage in the first year of production. Although legume intercropping did not affect cassava foliage and root production, others benefits on soil fertility and food provision for the household should be considered. Long-term harvesting of cassava foliage showed benefits in saving costs of production which would make the system more sustainable for smallholder-farmers.
Cassava (Manihot esculenta, Crantz) is an annual crop grown widely in the tropics as a tuber cash crop. Cassava tubers contain high levels of starch while the leaves have been used as a high protein source when collected at tuber harvesting time (Wanapat 2001). Alternatively systems for making hay from cassava foliage by harvesting the whole upper green part at early growth stage (3 months) and every 2-3 months subsequently have been demonstrated (Wanapat et al 1997). However, a sole crop of cassava may be considered a long-season crop (Polthanee et al 2001).
The legume crops have been considered to be suitable for use in intercropping systems with cassava which could possibly be used in improving soil fertility through their root nitrogen fixation and residues (Ashokan et al 1985). In addition, growing and using cassava as perennial forage with repeated harvesting of the foliage at 2-3 month intervals resulted in higher yields (Preston 2001).
Therefore, the objectives of these studies were
to investigate the effects of various types of legumes
intercropping on yield and nutritive values of cassava foliages,
and the potential of long-term harvesting system of cassava foliage
production in rainfed condition of Northeast of
Thailand.
There were two experiments to investigate the patterns of production, yield and chemical composition of cassava foliage.
In Experiment 1, sixteen plots (4x8 m each) were allocated according to a Randomized Complete Block Design (RCBD) to receive four planting patterns of cassava (Rayong 72-variety with 40x60 cm of planting space) as follows; without legume intercropping (control), intercropped with cowpea (Vignaunguiculata L.) (CP), intercropped with Stylosanthes guianensis (ST) and intercropped with Phaseolus calcaratus (PC). All legumes were intercropped every 2 rows per 4 rows of cassava. Initial harvesting at 3 months after planting and every 3 months subsequently was applied and measurements made of foliage yield and chemical composition. Yields of root were measured at the fourth harvesting. However, four plots of the control group were harvested for root only for half-area (4x4 m), and the remaining part left for the next year.
Experiment 2, the remaining parts of each of four cassava plots in the control group were continuously harvested for yields of foliage and root in the second year, and compared with the first year. All samples were analysed for DM, ash, CP (AOAC 1990), ADF and NDF (Goering and Van Soest 1970).
All data were subjected to analysis of variance using the GLM Procedure (SAS 1990). Treatment means were compared using Duncan's New Multiple Range Test.
Legume intercropping did not affect total yield of cassava foliage and root (Table 1). Cassava production without legume intercropping and with cowpea, Stylosanthesguianensis and Phaseoluscalcaratus intercropping produced 12.6, 10.9, 11.4 and 11 tonnes DM/ha of cassava foliage, respectively, and 2.7, 2.2, 2.9 and 3.0 tonnes DM/ha of cassava root, respectively. Chemical composition of cassava foliage did not differ among treatments (Table 2).
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Table1. Yield of cassava foliage and root in first year for control and inter-cropping systems |
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|
|
Control |
CP |
ST |
PC |
SEM |
|
Foliage, tonnes DM/ha |
|
|
|
|
|
|
1st harvesting |
2.3 |
2.3 |
2.1 |
2.2 |
0.11 |
|
2nd harvesting |
2.9 |
2.4 |
2.4 |
3.2 |
0.18 |
|
3rd harvesting |
2.4 |
1.6 |
2.0 |
2.0 |
0.11 |
|
4th harvesting |
5.1 |
4.5 |
4.9 |
4.4 |
0.26 |
|
Total |
12.6 |
10.9 |
11.4 |
11.9 |
0.52 |
|
Root |
|
|
|
|
|
|
Fresh, tonnes/ha |
11.3 |
9.3 |
11.9 |
12.4 |
0.57 |
|
Dry matter, tonnes DM/ha |
2.7 |
2.3 |
2.9 |
3.0 |
0.14 |
|
SEM= Standard error of the means |
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Table2. Chemical compositions of cassava foliage (%) |
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|
|
Control |
CP |
ST |
PC |
SEM |
|
DM |
25.4 |
26.0 |
26.2 |
27.0 |
0.36 |
|
Chemical composition |
% dry matter basis |
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|
Ash |
5.9 |
6.0 |
5.5 |
5.0 |
0.29 |
|
ADF |
53.1 |
52.1 |
56.0 |
56.5 |
1.45 |
|
NDF |
38.7 |
39.3 |
35.6 |
43.0 |
2.01 |
|
CP |
20.2 |
21.6 |
22.9 |
20.5 |
0.78 |
|
SEM= Standard error of the means |
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Total yields of cassava foliage and root were not different between first and second year of production (Table 3).
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Table 3. Yield of cassava foliage and root in the two years |
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|
|
First Year |
Second Year |
SEM |
|
Cassava foliage, tonnes DM/ha |
|
|
|
|
1st (5th, in second year) -harvesting |
3.4a |
6.9b |
0.48 |
|
2nd (6th, in second year) -harvesting |
4.3 |
6.9 |
0.54 |
|
3rd (7th, in second year) -harvesting |
3.5a |
5.5b |
0.31 |
|
4th (8th, in second year) -harvesting |
7.6a |
4.2b |
0.37 |
|
Total |
18.9 |
23.5 |
1.29 |
|
Sum of 2 years |
42.4 |
|
|
|
Cassava root |
|
|
|
|
Fresh, tonnes/ha |
16.9 |
21.1 |
1.30 |
|
Dry matter, tonnes DM/ha |
4.1 |
6.2 |
0.35 |
|
ab Values in the same row with different superscripts differ (P<0.05), SEM= Standard error of the means |
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Table 4. Chemical compositions of cassava foliage |
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|
|
Year 1 |
Year 2 |
SEM |
|
DM % |
25.4 |
27.9 |
0.59 |
|
Chemical composition |
% of dry matter basis…………….. |
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|
Ash |
5.9a |
8.2b |
0.18 |
|
ADF |
53.1a |
32.9b |
1.42 |
|
NDF |
38.7a |
21.4b |
1.24 |
|
CP |
20.2 |
24.1 |
0.98 |
|
ab Values in the same row with different superscripts differ (P<0.05), SEM= Standard error of the means |
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Crude protein content of cassava foliage was not different among first and second year of production (Table 4); however, ash was higher for second year cassava foliages while both acid and neutral detergent fiber (ADF and NDF) were higher for cassava foliage in the first year of production.
Long-term harvesting of cassava foliage was demonstrated as a potential feed production system particularly for smallholder farmers.
Legume intercropping was no effected on yield and chemical
compositions of cassava foliages and root, however, others effect
in order to soil fertility and providing of food for household
should be considered and further investigated. Long-term harvesting
of cassava foliage showed advantages on costs of production
which would be more sustainable system for farmers, however, more
research on cassava production particularly as perennial crop
should be conducted.
The authors and the research team members would sincerely like
to express their gratitude to the Tropical Feed Resources Research
and Development Center (TROFREC) for their kind
support.
AOAC 1990 Official methods of analysis of the Association of
Official Analytical Chemistry (15thEd), Washington,
D.C., U.S.A.
Ashokan P K, Vikraman R and Sudhadara K 1985 Studies on
cassava-legume intercropping systems for the Oxisols of Kerala
State, India. Trop. Agric. 62(4):313-318.
Goering H and P Van Soest 1970
Forage fiber analysis.
Agriculture hand book No.379. Unitied State Department of
Agriculture, Washington D. C., USA.
Polthanee A, S Wanapat,
M Wanapat and C Wachirapakorn
2001 Cassava-legumes intercropping: A potential food-feed system
for dairy farmers. Workshop on Current Research and Development on
Use of Cassava as Animal Feed, July, 2001. Eds: T.R. Preston, R.B. Ogle and M. Wanapat), held in Khon Kaen
University, Khon Kaen, Thailand.
SAS 1998
SAS/STAT Users Guide: Version 6,
12th Ed. SAS Institute, Cary, N.C., USA.
Wanapat M, Pimpa O, Petlum A and Boontao U 1997 Cassava
hay: A new strategic feed for ruminants during the dry season.
Livestock Research for Rural Development, 9(2):
http://www.cipav.org.co/lrrd/lrrd9/2/metha92.htm.
Wanapat M. 2001 Role of cassava hay as animal feed in the
tropics. Workshop on Current Research and Development on
Use of Cassava as Animal Feed, July, 2001. Eds: T.R. Preston, R.B. Ogle and M. Wanapat), held in Khon Kaen
University, Khon Kaen, Thailand.