Unlike chemical fertilizers, biofertilizer technology is based on renewable resources of energy and does not contribute to environmental pollution. As a low-cost technology it is most suitable for developing nations where labour is inexpensive and nutrient input for crop cultivation through chemical sources is meagre. Various micro-organisms and associations with plants which are involved in biofertilizer production as well as their usage on the farm are here reviewed. Data on possible monetary benefits to the small farmer who uses these biofertilizers in India are presented and future strategies of research in this area are pointed out. In addition to nitrogen, phosphorus also plays a vital role in plant growth and metabolism. Micro-organisms responsible for phosphate dissolution occur in intimate symbiotic association with plant roots and function as the liaison between the plant and the surrounding soil. Future biofertilizers will probably contain a blend of nitrogen-fixing and phosphate-mobilizing micro-organisms. Research aimed at developing these and at transferring nitrogen-fixing genes from bacteria into plants will result in a new biotechnology to minimize our dependence on chemical fertilizers.
Get full access to this article
View all access options for this article.
References
1.
DonaldsonG. F., Fertilizer issues in the 1970s and beyond. Development Digest, 13(4), 3–17 (1976).
2.
HardyR. W. F., Translating basic research on biological nitrogen fixation to improved crop production in less-developed countries–A user's views, inLinking Research to Crop Production, edited byStaplesR. C. and KuhrR. J., pp. 137–151. Plenum Press, New York (1980).
3.
VergheseM. C., Issues facing the world fertilizer industry, Proceedings of the FAI-IFDC Fertilizer Seminar, 1977 on trends in consumption and production, The Fertilizer Association of India, New DelhiPS-1/1–41 (1977).
4.
BradyN. C., The evaluation and removal of constraints in crop production, inLinking Research to Crop production, edited byStaplesR. C. and KuhrR. J., pp. 11–34. Plenum Press, New York (1980).
5.
AlexanderM. Introduction to Soil Microbiology (2nd edn), John Wiley and Sons, New York (1977).
6.
BurrisR. H., Overview of nitrogen fixation, inGenetic Engineering for Nitrogen Fixation, pp. 8–18. Edited byHollaenderA., PressPlenum, YorkNew (1980).
7.
RaoN. S. Subba, Biofertilizers in Agriculture, Oxford and IBH Publishers, New Delhi (1982).
8.
QuispelA., (Ed.)Biology of Nitrogen Fixation, North Holland Publishing Co., Amsterdam (1974).
9.
NutmanP. S.(Ed.). Symbiotic Nitrogen Fixation in Plants, Cambridge University Press, Cambridge, UK (1976).
10.
RaoN. S. Subba, SoiliMicro-organisms and Plant Growth, Oxford and IBH Publishing Co, New Delhi (1977).
11.
RaoN. S. Subba, (Ed.)Recent Advances in Biological Nitrogen Fixation, Oxford and IBH Publishing Co, New Delhi and Edward Arnold, London (1979).
12.
RaoN. S. Subba, (Ed.)Advances In Agricultural Micro biology, Oxford and IBH Publishing Co, New Delhi and Butterworths, UK (1982).
13.
FredE. B., BaldwinI. L. and McCoyE., Root Nodule Bacteria and Leguminous Plants, University of Wisconsin, Madison, Wisconsin, USA (1932).
14.
BurtonJ. C., Rhizobium culture and use, in Microbial Technology, edited byPeppierJ., pp. 1–33. ReinholdPublishing Corporation, New York (1967).
15.
DateR. A., Legume inoculant production. Proc, Indian Natl Sci. Acad. Part B40, 667–686 (1974).
16.
DateR. A., Principles in Rhizobium strain selection, in Symbiotic Nitrogen Fixation in Plants, edited byNutmanP. S., pp. 137–150. Cambridge University Press, Cambridge (1976).
17.
VincentJ. M., A Manual for the Practical Study of Root Nodule bacteria, ISP handbook No. 15, BlackwellPublications, Oxford (1970).
18.
BrockwellJ., Application of legume seed inoculants, inA Treatise on Dinitrogen Fixation, edited byHardyR. W. F. and GibsonA. H., Section IV Agronomy and Ecology, pp. 277–310. John Wiley and Sons, New York (1977).
19.
von BülowJ. F. W. and OobereinerJ.. Potential for nitrogen fixation in maize genotypes in Brazil, Proc. Natl Acad, Sci., USA, 72, 2389–2393 (1975).
20.
RaoN. S. Subba, inAssociative N2 Fixation, edited byVoseP. B. and RuschelA. P., CRC Press, Palm Beach, Florida, USA (1982).
21.
BoddeyR. M. and DobereinerJ.Association ofAzospirillum and other diazotrophs with tropical graminae, in Transactions of the 12th International Congress of Soil Science, New Delhi, Symposia papers I, pp. 28–47 (1982).
22.
TienT. M., GaskinM. H. and HubbellD. H.. Plant growth substances produced by Azospirillum brasilense and their effect on the growth of pearl millet, Appl. Environ. Microbiol. 37, 1012–1024 (1979).
23.
RaoN. S. Subba, TilakK. V. B. R., KumariM. Lakshmi and SinghC. S.. Azospirillum – a new bacterial fertilizer for bacterial crops. Science Reporter, CSIR (India), 16(10), 690–692 (1979).
24.
VenkataramanG. S. and KaushikB. D.. Save on N fertilizers by the use of algae in rice fields, Indian Farming27–30(October1980).
25.
VenkataramanG. S.. Nitrogen fixation by blue–green algae and its economic importance, inTransactions of the 12th International Congress of Soil Science, New Delhi, Symposia papers I, pp. 69–82 (1982).
26.
TalleyS. N., TalleyB. J. and RainsD. W.. Nitrogen fixation by Azolla in rice fields, inGenetic Engineering for Nitrogen Fixation, edited byHollaenderA., pp. 259–281. Plenum Press, New York (1977).
27.
TalleyS. N. and RainsD. W., Azolla as a nitrogen source for temperate rice, inNitrogen fixation, Vol. II, edited byNewtonW. E. and Orme-JohnsonW. H., pp. 311–320, University ParkPress, Baltimore (1980).
28.
FAO, China: Recycling of Organic Wastes In Agriculture, Food and Agricultural Organization, Rome (1977).
29.
WatanabeI., EspinasC. R., BerjaN. S. and AlimagnoB. V.. Utilization of theAzolla – Anabaena Complex as a Nitrogen Fertilizer for Rice, IRRI Research paper series No. 11 (1977).
30.
SinghP. K., Azolla plants as fertilizer and feed, Indian Farming27, 19–21 (1977).
31.
Zhuo-XinLi, Nitrogen fixation by Azolla in rice fields and its utilization in China, inTransactions of the 12th International Congress of Soil Science, New Delhi, Symposia papers I, pp. 83–95, (1982).
32.
PostgateJ. R.. The physiology and genetics of nitrogen fixation, inGenetic Manipulations with Plant Material, edited byLedouxL., pp. 123–134. Plenum Press, New York (1976).
33.
HollaenderA.. Genetic Engineering for Nitrogen Fixation, Plenum Press, New York (1977).
34.
GerretsenF. C.. The influence of microorganisms on the phosphorus uptake by the plant, Plant Soil1, 51–81 (1948).
35.
SperberJ. I.. Solution of mineral phosphates by soil bacteria, Nature, London180, 994–995 (1957).
36.
CooperR.. Bacterial fertilizers in the Soviet Union, Soils Fert. 22(5), 327–333 (1959).
37.
RaoW. V. B. Sundara and SinhaM. K.. Phosphate dissolving organisms in the soil and the rhizosphere, Ind. J. Agric. Sci. 33, 272–278 (1963).
38.
ChhonkarP. K. and RaoN. S. Subba. Phosphate solubilization by fungi associated with legume root nodules. Can. J. Microbiol. 13, 749–753 (1967).
39.
SethiR. P. and RaoN. S. Subba. Solubilization of tricalcium phosphate and calcium phytate by soil fungi, J. Gen. Appl. Microbiol. 14, 329–331 (1968).
40.
BajpaiP. D. and RaoW. V. B. Sundara. Phosphate solubilizing bacteria I. Solubilization of phosphate in liquid culture by selected bacteria as affected by different pH values, Soil Sci. Plant Nutrit. 17(2), 41–43 (1971).
41.
BajpaiP. D. and RaoW. V. B. Sundara. Phosphate solubilizing bacteria II. Extracellular production of organic acids by selected bacteria solubilizing insoluble phosphate, Soil Sci. Plant Nutrit. 17(2), 44–45 (1971).
42.
BajpaiP. D. and RaoW. V. B. Sundara. Phosphate solubilizing bacteria III. Soil inoculation with phosphorus solubilizing bacteria, Soil Sci. Plant Nutrit. 17(2), 46–53 (1971).
43.
PikovskayaR. I.. Mobilization of phosphorus in soil in connection with vital activity of some microbial species, Mikrobiologiya17, 362–370 (1948).
44.
MishustinE. N. and NaumovaA. N.. The use of bacterial fertilizers in sowing vegetable seeds into peat manure nutrient cubes, Mikrobiologiya25, 41–48 (1956),
45.
MishustinE. N. and NaumovaA. N.. Bacterial fertilizers, their effectiveness and mode of action, Mikrobiologiya31, 543–555 (1962).
46.
HarleyJ. L.. The Biology of Mycorrhiza, Leonard Hill, London (1969).
47.
MarksC. G. and KozlowskiT. T.(Eds), Ectomycorrhizae –iTheir Ecology, Physiology, Academic Press, New York (1973).
48.
MarxD. H.. Ectomycorrhiza fungus inoculation: a tool for improving afforestation practices, inTropical Mycorrhiza Research, edited byMikolaP.. Oxford University Press, Oxford (1981).
49.
GerdmanJ. W., Vesicular–arbuscular mycorrhizae, inThe Development and Function of Roots in 3rd Cabot Symposium, Harvard Forest, edited byTorreyJ. G. and ClarksonD. T.pp. 575–591. Academic Press, New York (1975).
50.
HaymanD. S.. Endomycorrhizae, inInteractions between Non-pathogenic Soil Microorganisms and Plants, edited byDommerguesY. R. and KrupaS. V., pp. 401–442. Elsevier, Amsterdam (1978).
51.
MosseB. and HaymanD. S.. Mycorrhiza in agricultural plants, inTropical Mycorrhiza Research, edited byMikolaP., pp. 21–230. Oxford University Press, Oxford (1980).
