The Journal of Food Technology in Africa Innovative Institutional Communications ISSN: 1028-6098 Vol. 6, Num. 4, 2001, pp. 121-125

The Journal of Food Technology in Africa, Vol. 6, No. 4, Oct-Dec, 2001 pp. 121-125

Response of Common bean to Rhizobium inoculation and fertilizers.

¹Amos A. O. Musandu.Ogendo and ²O. Joshua.

¹Department of Soil Science, Egerton University,
²Department of Agronomy, Egerton University, P.O. Box 536, Njoro, Kenya.

Code Number: ft01032

Abstract

Common bean (Phaseolus vulgaris) yields in western Kenya are low and this has been attributed to low soil fertility. Field trials were conducted in farmers fields in Ukwala Division of Siaya District in Kenya during the long rains of 1998 and 1999 to determine the potential for improving bean yields through Rhizobium inoculation, and fertilizer N and P applications. The three factors: Rhizobium inoculation at two levels and fertilizers-N and P each at three levels were factorially combined to give 18 treatments. The treatments were laid out in a randomised complete block design with a split-plot structure and three replications. A popular local bean variety Okuodo was used as the test crop. During the 1998 long rains season, P significantly (P=O.05) increased the stand count after emergence, pod number per plant and the bean grain yields. Seed number per plant alone was significantly increased by fertilizer-N application. Significant interaction effects (P=O.05) were observed for NXP on the stand count after emergence and for Rhizobium inoculation XP on stand count after emergence, stand count at harvest and the bean grain yields. Rhizobium inoculation alone did not significantly affect any of the measured variables in both seasons. In 1999, only the bean grain yields were determined and were significantly (P=O.05) increased only by fertilizer P applications

Introduction

Common bean (Phaseolus vulgaris) is an important source of protein and calories in human diets (Laing et. al, 1984; Smithson et. al., 1993). Kenya is a leading producer of beans in the eastern Africa region with over 500,000 ha. of land under the crop (Allen et. al., 1989). Most beans are produced by small holder farmers who rarely neither inoculate with Rhizobia nor apply fertilizers. Bean yields on farmers fields are usually low; ranging from 0.14 to 0.77 tlha (Kapkiyai et. al., 1998), with the national average standing at 0.50 t/ha (Ssali, 1988). For legumes, nodulation and N₂ -fixation are dependent upon an adequate supply of both macro and micro nutrients (Munns, 1977; Smith, 1982). These nutrients are not only essential for the symbiotic interaction but also for the host plant and its microbial partner. Russo and Perkins-Veazie (1992) have demonstrated that fertillizer N, P and K can increase bean yields even when supplied at rates above those recommended. Symbiotic N₂ -fixation begins only after nodule formation, which is preceded by colonization of the rhizo sphere and infection of legume roots by Rhizobia (Hardy et. al., 1971). Nitrogen requirement of legumes can be met by both mineral N assimilation and symbiotic N₂-fixation (George and Singleton, 1992). The plant N requirement may not be met during early vegetative and later productive phases by N₂- fixation. At these critical times, mineral N becomes the most important source of N for grain legumes. Poor nodulation and poor plant vigour have been observed in beans grown in soils low in extractable P (Amijee and Giller, 1998). Fertilizer P increases bean yields and causes optimum nodulation earlier during bean growth (Ssali and Keya, 1986). The bean crop is usually grown in association with maize. Among the benefits of the maize-bean intercrop system, include: enhanced pest tolerance (Ampofo and Massomo, 1998; Ugen and Chris, 1996), weed suppression (Wortman, 1993) and increased productivity (Wortman et. al., 1996). One of the major constraints to bean production in western Kenya is low soil fertility (Rachilo and Michieka, 1991). In six out often years, the high potential parts of western Kenya receive 1,300 to 1,700 mm precipitation per year. The precipitation is bimodal and allows for the growing of two maize crops per year (Jaetzold and Schmidt, 1983). Due to excessive leaching, the soils in this region are usually acid and low in N. Phosphorus is also frequently deficient in most soils (Karachi, 1979). The Grain Legume Project working in central Kenya recommended the use of Diammonium Phosphate fertilizer on beans to supply 36 kg N/ha and 40 kg P₂ O₅/ha (GLP, 1983). Ssali and Keya (1986) demonstrated that fertilization of beans promoted good early growth and that the beans fixed substantial amounts of dinitrogen.

This study aimed at enhancing bean production among the small holder farmers in western Kenya through the use of Rhizobium inoculation and moderate applications of fertilizers N and P.

Materials and Methods

Field experiments were conducted on a farmer¹s field in Ukwala Division of Siaya District during the long rains of 1998 and 1999. For site characterisation, composite top (0-20 cm) soil samples were taken from the trial site and subjected to physical and chemical analyses at the time of planting in 1998. The soils were classified as orthic Acrisols according to the FAO/UNESCO legend (1988). The soils were acidic, low in total N, organic C, available P and exchangeable bases (Table 1).

A popular local bean variety Okuodo was used as the test crop. The plot size was 4.0 m by 1.5 m. Each plot had four rows. The inter and intra row spacings were 0.5 m and 0.2 m respectively. Two seeds were placed in each of the ten hills per row. The outer two rows in each plot were guard rows while the inner two rows were used for data collection. The three factors: Rhizobium (with and without inoculation), N at three rates (0, 10 and 30 kg N/ha) and P also at three rates [(0, 20 and 40 kg P₂O₅/ha) in 1998 and at (0, 30 and 60 kg P₂O₅/ha) in 1999] were factorially combined to give 18 treatments. The treatments were laid out in a randomised

complete block design with a split-plot structure and three replications. The Rhizobium inoculum was prepared and supplied by the MIRCEN project at the Department of Soil Science, University of Nairobi. The sources of N and P were Calcium Ammonium Nitrate (26% N) and Triple Superphosphate (46% P₂O₅) respectively. In each of the planting seasons, the beans were sown at the end of February and harvested at the end of June.

Data collected included; pod and seed numbers per plant for the 4998 season and the bean grain field weight for both the 1998 and 1999 seasons. The data were subjected to analysis of variance using the statistical program MSTAT-C and the means separated by LSD.

Results and Discussion

Rhizobium inoculation did not influence any of the measured variables. Lack of response to Rhizobium inoculation has also been observed by Montealegre and
Graham (1996) who attributes it to the presence of numerous, ineffective indigeneous Rhizobia. According to Mcloughlin and Dunican (1985), competition between Rhizobia strains in the soil is a common phenomenon as the introduced inoculum strains compete with indigeneous Rhizobia for nodule sites. Montealegre et. al., (1995) suggests that cultivars that select strains, rather than nodulate with ineffective indigenous Rhizobia, offer one approach to the resolution of lack of response to Rhizobium inoculation problem. Moawad et. al., (1998), have found evidence of certain Rhizobia strains which only improve N₂ -fixation and bean yields in specific cultivars. It is therefore apparent that host variety and strain of Rhizobium difference in dinitrogen fixing ability could contribute significantly to the frequently observed unsatisfactory observed responses to inoculation (Graham, 1981).

Whereas some bean cultivars respond to Rhizobium inoculation, some only respond to applied N (Duque et. al,. 1985). Application of fertilizer-N, significantly (P=0.05) increased the bean seed number per plant alone (Figure 1). This conforms to observations made by Dadson and Acquaah, (1984) who found that in N deficient soils, small starter doses of applied N may stimulate nodule formation and enhance the grain yield of legumes. Phosphorus significantly (P=0.05) enhanced the establishment of the beans and increased the stand count after emergence , number of pods per plant, and the bean grain yields for the 1998 and 1999 seasons respectively (Figure 2). Phosphorus has been shown to promote the formation of nodes and pods in legumes (Buttery, 1969; Dadson and Acquaah, 1984). The responses due to applied fertilizer-N and P were consistent with the low fertility status of the soils (Table 1) on which the field trials were conducted. The low soil N status of the soils was expected to encourage a positive response to Rhizobium inoculation particularly in the presence of applied P. This observations contradict observations made by Gobara et. al., (1993). The response to applied P could be attributed to genotypic characteristics. Yan et. al., (1995) and Ssali and Keya, (1986) observed a close correlation between small seeded bean genotypes and P use efficiency. The smaller the seed size the more the efficient the use of P. Okuodo, the local bean variety used in this study is small seeded.

There was a significant (P=0.05) NxP interaction effect on the stand count after emergence (Table 2). This observation suggests that both N and P should be supplied to soils in which they are deficient in order to ensure good establishment of beans. Significant (P=0.05) interaction effects of Rhizobium inoculationXP were found on both the stand counts taken after emergence and at harvest (Table 3), and the bean grain yields (Figure 3). This interaction probably enhanced N assimilation reinforcing the observed response to N application.

Further investigations are needed to develop appropriate bioeconomic models for the various soil fertility niches, Rhizobia strains and soil types in western Kenya.

Conclusions

This study has clearly shown that in the low fertility orthic Acrisols of western Kenya, the P applications are key to enhancing bean yields on farmers¹ fields. However, there is need to determine the conditions under which beans would respond to Rhizobium inoculation as this would help in reducing the production cost of beans by the resource poor farmers whose production is limited to subsistence levels.

Acknowledgements

Thanks are due to the Rockefeller Foundation who provided a FORUM grant to the first author that made the accomplishment of this work possible. We also wish to thank all the very co-operative farmers of Ukwala and Boro Divisions of Siaya District with whom we have shared the results reported here.

References

• Allen, D.J., M. Desert., P. Trutmann and J. Voss. (1989). Common beans in Africa and their constraints. In: Bean production problems in the tropics. Schwartz, H.F and Pastor-Corrales, M.A. (Eds.). pp 9-32. CIAT, Cali, Colombia.
• Amijee, F and K. Giller. (1998). Enivironmental constraints to nodulation and nitrogen fixation of Phaseolus vulgaris L. in Tanzania. I. A survey of soil fertility, root nodulation and multi-locational responses to Rhizobium inoculation. African Crop Science Journal. 6:159-169.
• Ampofo, J and S. Massomo. (1998). Some cultural strategies for management of bean stem maggot (diptera: Agromyzidae) on beans in Tanzania. African Crop Science Journal. 6:351-356.
• Buttery, B.R. (1969). Analysis of the growth of soybeans as affected by plant population and fertilizer. Canadian Journal ofPlant Science. 49:675-684.
• Dadson, B.B and G. Acquaah. (1984). Rhizobiumjaponicum, nitrogen and phosphorus effects on nodulation, symbiotic nitrogen fixation and yield of soybean (Glycine max L. Merill) in the southern Savanna of Ghana. Field Crops Research. 9:101-108.
• Duque, F.F., M.C.P. Neves., A.A. Franco., R.L. Victoria and R.M. Boddey (1995). The response of field grown Phaseolus vulgaris to Rhizobium inoculation and the quantification of dinitrogen fixation using ¹⁵N. Plant and Soil. 88:333-343.
• FAOJUNESCO. (1988). Soil map of the world legend. Paris, France.
• George, T and P.W. Singleton. (1992). Nitrogen assimilation traits and dinitrogen fixation in soybean and common bean. Agronomy Journal. 84:1020-1028.
• Gobara, L.A.M,. A.A. Mahdi,. A.M. El-Tilib and M.H.M. Abdel. (1993). Response of Haricot bean to inoculation, nitrogen and phosphorus fertilization in Sudan. East African Agricultural and Forestry Journal. 59:41-51.
• GLP. (1983). Food beans in Kenya and part played in their improvement by the Grain Legume Project. NHRS. Thika. Kenya.
• Graham, P.H (1981). Some problems of nodulation and symbiotic nitrogen fixation in Phaseolus vulgaris L.: A Review. Field Crops Research. 4: 93-112.
• Hardy, R.W.F., R.C. Burns., R.R. Herbert., R.D. Hosten and E.K. Jackson. (1971). Biological nitrogen fixation. A key to world protein. ppp 561-590. In: Lie, T.A and E.G. Mulder (eds). Biological nitro gen fixation in natural and agricultural habitats. Plant and soil special volume ]97]. Martinus Nijhoff. The Hague Netherlands.
• Jaetzold, R and H. Schmidt. (1983). Farm management handbook ofKenya. Natural conditions and farm management information. West Kenya. MOA. Nairobi. Kenya.
• Kapkiyai, J., N. Karanja., P. Woomer and J.N. Qureshi. (1998). Soil organic carbon fraction in a long term experiment and the potential for their use as a diagnostic assay in highland farming systems of central Kenya. African Crop Science Journal. 6:19-28.
• Karachi, M.K. (1979).The effect of phosphorus on the growth of four pasture legumes. East African Agricultural and Forestry Journal. 44:312-317.
• Laing, D.R., P.G. Jones and J.H.C. Davis. (1985). Common Beans (Phaseolus vulgaris L.). In: The Physiology of Tropical Field Crops. Goldsworthy, P.R and N.M. Fisher. (eds). pp 305-351. John Wiley and Sons. New York. USA.
• Mcloughlin, J.J and L.K. Dunican (1985). Competition studies with Rhizobium trijohi in laboratory experiments. Plant and Soil. 88:139-143.
• Moawad, H., S.M.S.B. El Din and R.A. Abdel Aziz. (1998). Improvement of biological nitrogen fixation in Egyptian winter legumes through better management of Rhizobium. Plant and Soil. 204:95-106.
• Montealegre, C and P.11. Graham. (1996). Preference in the nodulation of Phaseolus vulgaris cv RAB 39.11. Effect of delayed nodulation or low cell representation in the inoculant nodule occupancy by Rhizobium tropici UMR 1899. Canadian Journal of Microbiology. 42:844-850.
• Montealegre, C and P.11. Graham., J.A. Kipe Nolt. (1995). Preference in the nodulation of Phase olus vulgar is cultivar RAB3 9. Canadian Journal ofMicrobiology. 41:992-998.
• Munns, D.N. (1977). Mineral nutrition and the legume symbioses. In. A Treatise on Dinitrogen Fixation. Section iv. Eds. Hardy, R.W.F and A.H. Gibson. pp 353-391. John Wiley an Sons. New York. USA.
• Rachilo, J.R and D.O. Michieka. (1991). Reconnaissance soil survey of the Busia area. Reconnaissance Soil Survey Report. No. R8. KARI/NARL. Kenya Soil Survey. Nairobi. Kenya.
• Russo, V.M and P. Perkins-Vezie. (1992). Cultural practices affecting yield and nutrient content of dry bean. Journal ofproduction Agriculture. 5:323-327.
• Smith, F.W. (1982). Mineral nutrition of legumes. In: Vincent, J.M (ed). Nitrogen Fixation in Legumes. pp 155-172. Academic Press. Sydney. Australia.
• Smithson, J.B., O.T. Edge and K.E. Giller (1993). Diagnosis and correction of soil nutrient problem of common bean (Phase olus vulgaris) in the Usambara mountains of Tanzania. Journal ofAgricultural Science, Cambridge. 120: 233-240.
• Ssali, H. (1988). Rhizobium phaseoli inoculation trials on farmers' fields in Kenya. East African Agricultural and Forestry Journal. 53:151 - 157.
• Ssali, H and S.O. Keya (1986). The effects of phosphorus and nitrogen fertilizer level on nodulation, growth and dinitrogen fixation of three bean cultivars. Tropical Agriculture (Trinidad). 63:105-109.
• Ugen, M and W.H. Chris. (1996). The effect of mixture proportions and fertilizer nitrogen on morphology, insect pest damage, competition and yield advantages in a maize/bean intercrop. African Crop Science Journal. 4:41-49.
• Wortman, C.S., H.F. Schnier and A.W. Muriuki (1996). Estimation of the fertilizer response of maize and bean intercropping using sole crop response equations. African Crop Science Journal. 4:51-55.
• Wortman, C.S. (1993). Contribution of bean morphological characteristics to weed suppression. Agronomy Journal. 85: 840-843.
• Yan, X.L., Lynch, J.P and Beebe, S.E. (1995). Genetic variation for phosphorus efficiency of common bean in contrasting soil types. I. Vegetative response. Crop Science. 35:1086-1093.

Copyright 2001 The Journal of Food Technology in Africa, Nairobi

The following images related to this document are available:

Photo images