Fate of blue-green algae in the food web of flooded rice-field ecosystems

1999 ◽  
Vol 29 (2) ◽  
pp. 141-145 ◽  
Author(s):  
S. K. Rakshit ◽  
N. T. Loan ◽  
S. Johnsen
Keyword(s):  
Food Web ◽  
Green Algae ◽  
Rice Field ◽  
Blue Green Algae ◽  
Flooded Rice ◽  
Flooded Rice Field

Microbial Degradation of Penoxsulam in Flooded Rice Field Soils

2006 ◽  
Vol 54 (16) ◽  
pp. 5962-5967 ◽  
Author(s):  
Thomas W. Jabusch ◽  
Ronald S. Tjeerdema
Keyword(s):  
Microbial Degradation ◽  
Rice Field ◽  
Flooded Rice ◽  
Field Soils ◽  
Flooded Rice Field

Effect of the herbicide butachlor on methane emission and ebullition flux from a direct-seeded flooded rice field

2001 ◽  
Vol 33 (3) ◽  
pp. 175-180 ◽  
Author(s):  
S. R. Mohanty ◽  
K. Bharati ◽  
B. T. S. Moorthy ◽  
B. Ramakrishnan ◽  
V. R. Rao ◽  
...  
Keyword(s):  
Methane Emission ◽  
Rice Field ◽  
Flooded Rice ◽  
Direct Seeded ◽  
Flooded Rice Field

scholarly journals Methane emission and dynamics of methanotrophic and methanogenic communities in a flooded rice field ecosystem

2014 ◽  
Vol 88 (1) ◽  
pp. 195-212 ◽  
Author(s):  
Hyo Jung Lee ◽  
Sang Yoon Kim ◽  
Pil Joo Kim ◽  
Eugene L. Madsen ◽  
Che Ok Jeon
Keyword(s):  
Methane Emission ◽  
Rice Field ◽  
Flooded Rice ◽  
Field Ecosystem ◽  
Flooded Rice Field

A Comparison of the Use of Azolla and Blue-green Algal Bio-fertilizers with Green Manuring, Organic Manuring and Urea in Transplanted and Direct-seeded Rice

1989 ◽  
Vol 25 (4) ◽  
pp. 485-491 ◽  
Author(s):  
A. L. Singh ◽  
P. K. Singh
Keyword(s):  
Green Algae ◽  
Nitrogen Uptake ◽  
Rice Field ◽  
Nitrogen Sources ◽  
Poor Response ◽  
Rice Crop ◽  
Green Manuring ◽  
Blue Green Algae ◽  
Green Algal ◽  
Direct Seeded

SUMMARYAzolla and blue-green algae (BGA) inoculated in a rice field produced a higher biomass and fixed more nitrogen in transplanted than in direct-seeded rice. Application of Azolla, BGA, composts of Eichhomia and Azolla and green manuring with Sesbania increased tiller numbers, height, grain and straw yields, and nitrogen uptake by rice in both the transplanted and the direct-seeded crop. The growing and incorporating of three Azolla crops with the rice crop produced more grain than the use of other nitrogen sources but the rice crops showed a poor response to inoculation with BGA. The yield of rice following green manuring with Sesbania or the use of two crops of Azolla after transplanting was similar to that of a crop receiving 60 kg N ha−1 as urea, but smaller yields resulted from the use of composts of Azolla and Eichhornia.

Sockeye salmon (Oncorhynchus nerka) nursery lake fertilization: Review and summary of results

2004 ◽  
Vol 12 (3) ◽  
pp. 133-162 ◽  
Author(s):  
K D Hyatt ◽  
D J McQueen ◽  
K S Shortreed ◽  
D P Rankin
Keyword(s):  
Food Web ◽  
Green Algae ◽  
Sockeye Salmon ◽  
Inorganic Nitrogen ◽  
Oncorhynchus Nerka ◽  
Adult Survival ◽  
Bottom Up ◽  
Blue Green Algae ◽  
Marine Survival ◽  
Lake Fertilization

We reviewed 24 sockeye salmon (Oncorhynchus nerka) nursery lake experiments that involved whole-lake fertilization with appropriate treatment and control years. We found that: 21 of 21 studies showed that fertilization was associated with increased chlorophyll a concentrations, 16 of 16 showed increased zooplankton biomasses, 16 of 16 demonstrated increased average smolt weights, and 11 of 13 showed increased smolt biomasses. Studies involving assessments of egg-to-smolt survival were rare, but all (4 of 4) showed increased survival rates. Studies involving increased smolt-to-adult survival (i.e., marine survival) were even rarer, but all (3 of 3) showed that lake fertilization and increased smolt size were associated with increased marine survival. Several fertilization studies reported problems, and some offered solutions. For instance, when whole-lake fertilization stimulated the growth of blue-green algae, fertilizer with higher nitrogen to phosphorus ratios was used to control the problem. Conversely, when high nitrogen to phosphorus ratios were associated with blooms of ungrazable diatoms, notably Rhizosolenia eriensis, reduced nitrate concentrations were recommended. To date, solutions designed to constrain the growth of both blue-green algae and Rhizosolenia blooms remain elusive. Some studies showed that when both mysids (large invertebrate planktivores) and juvenile sockeye inhabit the same lake, sockeye suffer from a competitive disadvantage and mysids consume 80–90% of the available zooplanktonic food production. Similarly, a small number of studies demonstrated that competition from sticklebacks (Gasterosteus aculeatus) adversely affected sockeye growth rates, and although the problem remains unresolved, ongoing work in lakes containing kokanee (O. nerka), suggests that stocked cutthroat trout (Salmo clarki) may be capable of controlling stickleback densities through predation. Despite all of these difficulties, in almost all cases, when lakes were fertilized with various mixtures of inorganic nitrogen and phosphorus, pelagic food web bottom-up control was strong enough and predictable enough to ensure that sockeye smolt biomass increased. We conclude that sockeye nursery lake fertilization is a technique that can contribute usefully to both the enhancement and conservation of sockeye salmon populations. Key words: sockeye salmon, lake fertilization, bottom-up, aquatic food web.

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