Nguyen Thi Mui, Dinh Van Binh, Nguyen Phuc Tien and Ngo Tien Dzung
NIAH Goat and Rabbit Research Center, Son Tay, Ha Tay, Vietnam

ABSTRACT

A trial to determine the biomass production, feeding value and effects on soil fertility of Flemingia macrophylla was conducted in the hilly land of North Vietnam. Results showed that fresh edible biomass production of Flemingia macrophylla was high and CP and fiber contents were also high. Flemingia macrophylla demonstrated superior growth and productivity over a range of location especially when planted to sloping lands to prevent the occurrence of soil erosion. Flemingia macrophylla being a rich source of protein can increase liveweight gain of animals and serve as an effective feed supplement. Results also showed that soil chemical properties were improved in areas planted with Flemingia macrophylla.

INTRODUCTION

Flemingia (Flemingia macrophylla) is a woody, deep rooted shrub that is found in Asia and Sub-Saharan Africa (Asare et al. 1984). Flemingia is considered to be an excellent plant for soil conservation (Susilawati et al. 1997). The plant has a high leaf stem ratio (Perera et al. 1994), providing high fresh edible biomass for animals. Flemingia has a high protein content of around 19% of dry matter (Dzowela et al. 1995) and is therefore consider an excellent feed. Flemingia appears   to   have   some value  as  a  dry season browse (Skerman 1977) and increasing the cutting intervals from 12 to 14 weeks decreased its crude protein content (Asare 1985).

METHODOLOGY

In 1994, the first trial was conducted at Bavi district, Hatay province, 60 km north-west of Hanoi. The climate is monsoon-tropic, with a wet season between April and November and a dry season from December to March. Average annual rainfall is 1,850 mm, with a mean temperature ranging from 24 to 30o C.

The pH of the soil at the experimental areas ranging from 3.5 to 4.1, K2O of  0.11 to 0.16%, and P2O5 of 0.06 to 0.09%. Drought occurs frequently in the areas. A total of 200 seeds of Flemingia was planted in single rows spaced at 50 cm apart for biomass yield and seed production. In 1995, three kg of seed was obtained from first harvest and was planted in an area of 3000 m2 in the sloping land of Bavi district. Trials were extended to 4 ha area planted with Flemingia stand, 10 ha in association with fruit trees and to 4 ha farm  in Hatay province, North Vietnam. From 1998, there were already  300 ha of hilly land areas planted to Flemingia to improve soil fertility and prevent soil erosion. Eucalypthus and Guinea grass were planted to compare the effects of Flemingia macrophylla on soil fertility.

RESULTS AND DISCUSSION

1.   Growth rate and biomass  production
The seedlings of Flemingia macrophylla were observed to be very weak and had difficulty in competing with the weeds. In the first few months, rate of growth of Flemingia macrophylla was very slow but grew fast after 6 months and reaching a height of 1.73 m in 360 days. Average fresh edible biomass yield for 4-year period was 9.33 tons/year. Year 1 had the lowest total fresh edible biomass yield of 5.97 tons/ha (3 cuttings only) while year 2 had the highest value of 60.7 tons/ha  (6 cuttings). Wet season yield contributed 70 % of the total yield.

2.   Feeding value
Flemingia macrophylla has a crude protein content of 173 g/kg dry matter (DM) and 380 g/kg DM crude fiber. The forage has a tannin content of 20.1 g/kg DM.

3.   Seed production
An average of 125 kg/ha of seeds was harvested during year 2 and 3. One kg has more or less 54,000 seeds. Mean germination rate of the seeds was 70 %.

4.   Soil nutrient status
Soil fertility was improved by planting Flemingia macrophylla. Results showed that % N, % P2O5, % K2O and % carbon of soil increased in 3 years after planting. Soil pH increased from 3.75 to 4.01. NPK and carbon contents decreased in soil planted with Guinea grass. The pH of soil plant with Eucalyptus also decreased.

This study also confirms the findings of Phan Gia Tan (1995) and Nguyen Thi Mui et al (1996a, 1996b, 1997) concerning the beneficial effect of sugar cane on soil fertility. Flemingia improves the soil fertility, thus this apparent improvement could be attributed to the fact that Flemingia is a legume, able to fix nitrogen in soil of high acidity and low fertility.

5.   Feeding value of Flemingia macrophylla
Flemingia macrophylla has high protein content (Dzowela, et al. 1995) and is interesting as a supplementary feed for animals but due to high tannin content, Flemingia is not advisable for and preferred by livestock. Lanting (1999) proposed the theory that a small addition of Flemingia can reduce protein degradation in the rumen, making a higher proportion of protein available for the animal in the hindgut resulting to higher liveweight gains.

CONCLUSION

Flemingia macrophylla is recognized as a multipurpose species due to its several uses such as high protein forage, its capability to produce high volumes of fuel-wood and its capacity for soil amelioration and protection from soil erosion and run-off.

REFERENCES

Asare, E.O., 1985. Effect of frequency and height of defoliation of forage yield and crude protein content of Flemingia macrophylla. In proceeding of The XV International Grassland Congress, August pp. 24-31, Kyoto, Japan

Asare, E.O.: Shebu, Y. and Agishi, E.A., 1984. Preliminary studies on indigenous species for dry season grazing in the Northern Guinea  18 pp. 148-152.

Bazill, Y.A.E., 1987. Evaluation of tropical forage legumes under Pinas caribea var. Hondurensis in Costa Rica, pp. 97-108.

Dzowela, B.H., Hove, L., Topps, J.H., Mafongoya, P.L., 1995. Nutritional and anti-nutritional characters and rumen degradability of dry matter and nitrogen for some multipurpose tree species in Zimbabwe. 55, pp. 207-214.

Lanting, E.F., 1999. Using stylo CIAT184 to improve sheep production. Southeast Asia Feed Resource Research and Development Network, pp. 7-8.

Nguyen Thi Mui, Preston, T.R and Ohlsson, I., 1996a. Response of four varieties of sugar cane to planting distance and mulching. Swedish University of Agricultural Sciences, Uppsala, Sweden.

Nguyen Thi Mui, Ohlsson, I. and Preston, T.R, 1996b. Effect of management practices on yield and quality of sugar cane and on soil fertility. Swedish University of Agricultural Sciences,  Sweden.

Perera, A.N.F., Djajanegara, A., Sukmawati, A., 1994. Yield and feeding value of leguminous fodder species grown as hedge rows in sloping lands of Sri Lanka.

Phan Gia Tan, 1993. Effect on production of sugar cane and on soil fertility of leaving the dead leaves on the soil, Sustainable Livestock Production on Local Feed Resources. pp. 28-32.

Skerman, P.J., 1977. Tropical forage legumes. FAO Plant Production and Protection Series, No 2 FAO, Rome.

Susilawati, S.H., Budhi, G.S., Rusastra, W., 1997. Alley cropping farming systems in Indonesia. Improving smallholder farming systems in Imperata areas of Southeast Asia, p. 20