Soil Ph and Its Role in Cyanobacterial Abundance and Diversity in Rice Field Soils

Abstract

Nayak -Prasanna: Soil pH and its role in cyanobacterial abundance and diversity in rice field soils - Abstract. The influence of soil pH was evaluated on the abundance and generic diversity of cyanobacteria in soil samples collected from diverse rice soil ecologies of India. Qualitative and quantitative studies of the 52 soil samples collected from nine agroecologies was carried out using enrichment, MPN (Most Probable Number) techniques and diversity indices were measured. A total of 166 forms, including 130 heterocystous and 36 non-heterocystous isolates were isolated and the highest percentage of abundance of heterocystous forms was observed at pH of 8.1. Highest Shannon's diversity index was recorded at a pH of 6.9, followed by pH of 7.4, while indices of richness and evenness (J and E) were highest in soil samples of pH of 9.3. This study highlighted the successful colonization of cyanobacteria in rice field soils of diverse pH and the need for enrichment of the native flora as a means of exploiting the full potential of cyanobacterial biofertilizers in agriculture

Application of blue-green algae and mineral fertilizers to direct seeding lowland rice

“…The contribution of biological nitrogen fixation of BGA to the rice ecosystems has been well documented. However, pH lower than 6.9 limits the success in application of BGA in agriculture 21 . In previous investigations, rice yield was closely correlated with plant nutrient uptake 22 .…”

Evaluating the potential of N. calcicola and its bicarbonate resistant mutant as bioameleorating agents for ‘usar’ soil

“…pH is one of the important factors determining the cyanobacterial biodiversity and abundance in any environment [20,21]. In culture media, the optimal pH for cyanobacterial growth ranges from 7.5-10, the lower limit being 6.5-7.0 [22].…”

Growth Performance and Yield Potential of Cereal Crops (Wheat, Maize and Barley) in Association with Cyanobacteria

“…Fertilization with phosphorus and potassium increased these grains greatly. Some 25-30% of the nitrogen fixed by the blue-green algae is taken up by the rice plants (Watanabe and Roger, 1984).The role of cyanobacteria as biofertilizer has largely been reviewed by Dola Bhowmik et al, (2010), Nayak andPrassana (2007) Ordog (1999), Haroun and Hussein (2003), Lakshmi and Annamalai (2008), Gallab and Salem (2001), Venkataraman (1972), Singh (1961) and Relwani and Surahmanyan (1963), etc.…”

“…Besides fixing atmospheric nitrogen, cyanobacteria play a major role in reducing soil erosion because of ability to secrete polysaccharides that bind soil (Nayak and Prassana, 2007). They also control soil run off and increase soil organic matter content and in producing certain substances which enhance the growth of plants (Ordog, 1999).…”