Biomass production of Moringa oleifera and some legumes in the hilly area of Tinh Bien district, An Giang province
 

 Luu Huu Manh, Nguyen Nhut Xuan Dung and Vo Tong Xuan*

Department of Animal Husbandry, Cantho University
lhmanh@ctu.edu.vn
* An Giang University, An Giang

                                                                       

Abstract

A study on the growth and biomass production of  Moringa oleifera, Leucaena leucocephala, Desmanthus virgatus, Psophocarbus tetragonolobus, Pueraria phaseoloides and Centrosema pubescens was carried out in the hilly area of Tinh Bien District, An Giang province. The experiment was designed as a randomized complete block with 6 replicates. All plants were planted as seedlings with 0.8m*0.6m spacing. The equivalents of five tonnes/ha of cattle manure were applied in pits before planting. Chemical fertilizer (100-90-30) was applied, with one-fifth of the total fertilizer amount after each harvest.

The results of two harvests in the seven months after planting show that the biomass production of the herbaceous legumes Psophocarbus, Pueraria and  Centrosema were higher than those from the trees/shrubs (Moringa, Leucaena and Desmanthus). However, crude protein contents of the latter group were higher than of the herbaceous legumes.

It is concluded that all species grow well on the hilly, low-fertility, weathered soils of Tinh Bien district.

Key words: Moringa oleifera, Leucaena leucocephala, Desmanthus virgatus, Psophocarbus tetragonolobus, Pueraria phaseoloides, Centrosema pubescens, biomass, growth

Introduction

 

Tinh Bien district is located along the border with Cambodia and is a hilly area. The agricultural land is divided into two areas: the lowlands, located at an attitude up to 4 m above sea level, where the farmers plant two crops of rice, and the highland area, located at an attitude between 4 and 30 m above sea level. People in this area plant one crop of rice and other crops such as cassava, mung bean, sweet potato, pumpkins, water melon and cabbage, often in combination with perennial trees. Farmers keep cattle for ploughing and meat. The performance of animals is poor and productivity is low due to lack of feed supplements (Nguyen Van Hung, personal communication). The available protein sources for animals are very limited, particularly in the dry season. Lack of water is also a serious problem in this area where ethnic people, mainly the Khmer (80%), are living.

 

In the dry season there is very little green forage in the field, with the exception of some woody plants such as Acacia mangium and Acacia auriculiformis, which were planted as reforestation and not used as animal feed. Some leguminous trees, such as Leucaena leucocephala and Pithecelellobium dulce grow naturally, but are not common (Nguyen Nhut Xuan  Dung 1996).

 

The objective of this study was to introduce and evaluate some legumes to supply green biomass for animals, protect against soil erosion and also improve soil fertility.

 
 

Materials and methods

 

The experiment was carried out at the private cattle farm owned by Nguyen Van Huu, in Nha Ban town, Tinh Bien district, An giang province and started on 28^th  June, 2002. The climate is tropical monsoon. The rainy season occurs from May to November with the yearly rainfall in the range of 1800-2000mm. Temperature ranges between 28 and 30^oC. Air humidity varies from 70 to 85%. The soils are weathered sandy soils, with very poor fertility and very low organic matter, and pH is 4.5 to 5.0 in the topsoil.

 

Six species of tree, shrub and herbage were planted in a randomized complete block design, with 6 replicates. The species were: Moringa oleifera (local cultivar), Leucaena leucocephala (local cultivar), Desmanthus virgatus, Pueraria phaseoloides, Psophocarbus tetragonolobus (Thailand cultivar) and Centrosema pubescens,  and were planted at 0.8m*0.5m spacing. The total size of each plot was 5*5m. All species were prepared in a nursery on 19 June and transplanted as seedlings on 21 July, 2002. The equivalent of 5 tonnes/ha of cattle manure were applied in pits one week before planting. Chemical fertilizer was applied (100-90-30, NPK), one-fifth of the total fertilizer after each harvest. Weeds were controlled as they appeared.

 

Plant height/length and biomass yield were recorded at 60, 90 and 120 days after  planting. Green biomass was taken from a 4 x 2m area. For the trees and shrubs, samples were collected from the top to the end of the soft stem part, considered as potential feed. For herbaceous legumes, biomass was taken from the top to 50cm distance from the root to ensure that they could re-grow well. Samples were analysed for dry matter, crude protein and crude fiber according to AOAC (1990) procedures.
 

 

Results and discussion

 

The results in Table 1 show that all the herbaceous legumes grew faster than the tree and shrub legumes. Psophocarbus grew fastest in terms of length, followed by Pueraria and Centrosema. Moringa and Desmanthus were similar in growth and Leucaena had the lowest growth rate.

 

During the first 2 months, all plants grew more slowly than in the third and forth months. This is a general natural characteristic of the legumes,  that develop very slowly in the first stage of the growth cycle. The results for Leucaena and Pueraria were also lower than in other studies in Vietnam (Le Quang Nghia 1978; Nguyen Thi Trong 1981), which was probably due to differences in the soil fertility of the experimental sites. 

 

The herbaceous plants gave higher biomass than trees and shrubs for both the 1^st and 2^nd cutting (Table 2). In the herbaceous group, Pueraria gave higher yields than Psophocarbus and Centrosema grew slowest. Desmanthus and Moringa gave similar green biomass yields that were higher than from Leucaena. The results for Pueraria and Centrosema are lower than values reported by other authors (Le Quang Nghia 1978; Nguyen Thi Trong 1981; Truong van Quang 1979).

 

The productivity of the re-growth cutting from trees and shrubs was somewhat higher than those from the 1^st cutting. However, the values from the herbaceous group were all lower than those from the first cutting. The contrasting results of this experiment can be explained by the fact that the dry season came during the period of re-growth, and it is known that the drought tolerance of  herbaceous legumes is much lower than that of trees or shrubs due to their shorter root system.

 

Dry matter and fibre contents of the legumes were not different between species (Table 3). Crude protein contents of Moringa, Leucaena Psophocarbus and Pueraria were similar and higher than in Desmanthus. 

 

 

 

Conclusions and recommendations

 

• For green forage production in the hilly, low-fertility soils of Tinh Bien district, the herbaceous legumes Psophocarbus, Pueraria and Centrosema and the Moringa tree produced more crude protein per ha than Leucaena and Desmanthus.

• All species developed well on the low-fertility, weathered soils in the Tinh Bien hilly area. However, it is necessary to monitor their drought tolerance, especially the herbaceous legumes.

 

Acknowledgements

This research was partially financed by the bilateral SAREC project 2000-2002.

 

References

 

Le Quang Nghia 1978 Biomass production of some legumes planted in Cantho. BSc thesis, Cantho University.

 

Nguyen Thi Trong 1981 Biomass production of Pueraria phaseoloides with different fertilizer formula. BSc Thesis, Cantho University.

 

Truong van Quang 1979  Biomass production of elephant grass and tropical kudzu mixture. BSc Thesis; Cantho University.

 

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