Seasonal change of N₂-fixing rate in rice field assayed byIn Situacetylene reduction technique

Seasonal change of N2fixing rate in rice field assayed byIn Situacetylene reduction technique

“…Endogenous ethylene evolution was about 0.05 mmol C 2 H,/m 2 .day, and did not significantly affect the results. The highest N2 fixing activity attributed to blue-green algae also appeared at the ratoon stage as reported previously (7). Results of field acetylene reduction assays in the dry season are shown in Fig.…”

“…In situ (field) assays using the acetylene reduction technique have been conducted in flooded rice fields at the International Rice Research Institute (IRRI) (7). The rates of acetylene reduction observed were ascribed mainly to photodependent algal fixation.…”

EFfect of phosphorus on N2-fixation as measured by the field acetylene reduction technique in Thailand long-term fertility plots

“…However, such trials are rarely undertaken in tropical paddy fields. Surveys of the N2-fixing activity in these fields may be of high value since the nitrogen fertility of the fields is easily evaluated.-One of the present authors has previously reported results for N2-fixing rate assays in long-term fertility plots in the Philippines (11).…”

“…ARA assays. The techniques reported in previous papers (11,12) were used. Assays were conducted from the 1976 wet season to the 1978 dry season.…”

Quantitative study on nitrification in flooded rice soil

“…Fertilized (60-30-30 kg N-P 2 0 5 -K 2 0/ha) and unfertilized plots of the long-term fertility trial (started in 1964 with 2 rice crops a year at IRRI) were used (18). A metal frame (20 x 20 em) was placed among 4 hills of rice, and the floodwater and weeds were removed with minimal disturbance to the surface.…”