Global Advanced Research Journal of Agricultural Science (GARJAS) ISSN: 2315-5094
January 2014 Vol. 3(1): pp. 001-007
Copyright © 2014 Global Advanced Research Journals
Sustainable growth of rice in Ghana: The role of biofertilizers (Phosphate solubilizing microorganisms and Azolla anabaena) to rice improvement.
Department of Soil Science, College of Agriculature and Consumer Sciences, University of Ghana, Legon.
Accepted 16 December, 2013
Phosphorus deficiency in soil is a major constraint to food production in Ghana. This makes phosphate solubilizing microorganisms (PSM), organisms that make inorganic phosphates available for plant use important in the Ghanaian agriculture. Many PSMs have been isolated worldwide, some having been shown to be good solubilizers of inorganic phosphates and others not. Bioinformatic analysis showed that good phosphate solubilizers have the pqq and the pho genes. In a previous pot experiment, isolated PSM was tested on upland rice (Nerica 2). In field trials, the use of 45 kg P2O5/ha TSP + PSM out yielded the treatment with only 45 kg P2O5/ha TSP was applied to rice crop. The other important nutrient that constraints food production is inorganic N. Azolla is an aquatic fern that harbors an algal symbiont Anabaena azollae, capable of converting the tightly bound atmospheric nitrogen gas (N2) which is unavailable to plants into inorganic N forms utilizable by plants. The successful cultivation and incorporation of Azolla into flooded soils where it commonly occurs results in the accumulation of large amounts of plant utilizable N for rice cultivation. Many azolla strains were introduced into the country and year round productivity trials were conducted. Promising azolla strains with high productivity and less variability in productivity from season to season were selected for further field trials. One azolla crop after incorporation before or after transplanting lowland rice increased the yield of rice by 17 % over the control treatment where no nitrogen fertilizer was used. Azolla supplemented the nitrogen requirement of rice and reduced the number of times one had to weed the rice farm, it was economical to use azolla.
Keywords: Rice improvement, Biofeterlizer, Phosphate solubilizing microorganisms and Azolla anabaena.