Effects of inoculation of cyanobacteria on nitrogen status and nutrition of rice (Oryza sativa L.) in an entisol amended with chemical and organic sources of nitrogen

• Published in: Biology and fertility of soils Vol. 24; no. 1; pp. 123 - 128
• Main Authors: Ghosh, T.K, Saha, K.C
• Format: Journal Article
• Language: English
• Published: Berlin Springer 01.01.1997; Springer Nature B.V
• Subjects: Agronomy. Soil science and plant productions; ammonium compounds; Anabaena; animal manures; Aulosira; Biochemistry and biology; Biological and medical sciences; Biotechnology; Chemical, physicochemical, biochemical and biological properties; crop yield; Cyanobacteria; Entisols; flooded conditions; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; grains; Immunization; Loam soils; Microbiology; mixtures; neem kernel meal; nitrates; nitrogen; Nitrogen fertilization; nitrogen fertilizers; nitrogen fixation; Nitrogen, phosphorus, potassium fertilizations; Nostoc; Nostoc muscorum; nutrient sources; nutrient uptake; organic versus inorganic fertilizers; Oryza sativa; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant nutrition; Rice; rice soils; rice straw; Sesbania bispinosa; soil; soil fertility; soil inoculation; soil nitrogen pools; Soil science; soil solution; Soil-plant relationships. Soil fertility. Fertilization. Amendments; species; submergence; urea; Asia; West Bengal; India; Monocotyledones; Wet-rice cultivation; Soil fertility; Nostoc muscorum; Cultivated soil; PADDY SOILS; Meliaceae; Cereal crop; Fertilizers; Tropical soil; Oryza sativa; Gramineae; Dicotyledones; Angiospermae; Cyanobacteria; Anabaena; Soil biology; Bacteria; Spermatophyta; Nostoc commune; Diazotrophy; Azadirachta indica
• ISSN: 0178-2762; 1432-0789
• DOI: 10.1007/BF01420232

A field experiment was conducted with wetland rice (Oryza sativa cv. IR-36) in a sandy clay loam soil (Entisol) to study the effect of inoculation with a soil-based mixed culture of four diazotrophic cyanobacteria, Aulosira fertilissima, Nostoc muscorum, N. commune and Anabaena spp., on the N-flux in inorganic (NH4+ NO3+ NO2(-)), easily oxidizable, hydrolysable and non-hydrolysable forms of N in soil during vegetative growth periods of the crop. Effects on grain and straw yield and N uptake by the crop were estimated. The effects of applying urea N and N as organic sources, viz. Sesbania aculeata, Neem (Azadirachta indica) cake and FYM, each at the rate of 40 kg N ha-1, to the soil were also evaluated. Inoculation significantly increased the release of inorganic N, evidenced by its increased concentrations either in soil or in soil solution. However, such increases rarely exceeded even 4% of total N gained in different forms in the soil system by inoculation during the vegetative growth stages of the rice plant, when the nutritional requirement of the plants is at a maximum. Most of the N2 fixed by cyanobacteria remained in the soil as the hydrolysable form (about 85%) during this period. Inoculation caused an insignificant increase in grain (8%) and straw (11%) yield, which was, however, accompanied by a significant increase in N uptake by the grain (30%) and an increase in total uptake of 15.3 kg N ha-1. Such beneficial effects of inoculation varied in magnitude with the application of organic sources, with farmyard manure (FYM) being the most effective. Application of urea N, on the other hand, markedly reduced such an effect.