Title: Atmospheric nitrogen fixation by photosynthetic microorganisms in a submerged Philippine soil
Abstract:Abstract Photosynthetic nitrogen-fixing microorganisms help maintain the nitrogen level of soil in rice paddies when environmental factors favor the growth of microorganisms. Our studies showed that b...Abstract Photosynthetic nitrogen-fixing microorganisms help maintain the nitrogen level of soil in rice paddies when environmental factors favor the growth of microorganisms. Our studies showed that blue-green algae in particular have a significant role in nitrogen-fixation in light. The most active nitrogen-fixation by microorganisms occurred in the soil shortly after it had been submerged under light. The longer the submergence, the less nitrogen microorganisms were fixed. In a greenhouse experiment, the fixed nitrogen appeared not to be immediately available to the rice plant. The amount of nitrogen that can be fixed in the field by nitrogen-fixing microorganisms in paddy water was estimated using the acetylene reduction method during the rice-growing period. The amount of nitrogen fixation by these microorganisms is not sufficient to account for the amount of nitrogen uptake by rice during the rice-growing period. This paper was presented at the Second ASEAN Soil Conference in Indonesia in July 1972. This paper was presented at the Second ASEAN Soil Conference in Indonesia in July 1972. Notes This paper was presented at the Second ASEAN Soil Conference in Indonesia in July 1972.Read More