PD/A CRSP Nineteenth Annual Administrative Report
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Subcontract No. RD010A-07
Auburn University, Alabama
|Claude E. Boyd||US Principal Investigator|
|C. Wesley Wood||US Principal Investigator|
|Taworn Thunjai||Graduate Assistant (Thailand; CRSP funded)|
|Oscar Zelaya||Graduate Assistant (Honduras; CRSP funded)|
|Kom Silapajarn||Graduate Assistant (Thailand; from May 2001; partially CRSP funded)|
|Orawan Silapajarn||Graduate Assistant (Thailand; from May 2001; partially CRSP funded)|
|Francisco Gomes||Graduate Assistant (Portugal; from June 2001; partially CRSP funded)|
The interactions among nutrients, primary and heterotrophic productivity, and fish yield are known as pond dynamics. Water quality imbalances that have their origins in interactions between pond soil and water are not fully understood. Current PD/A CRSP research in pond dynamics focuses on the influence of pond bottom soils on water quality and productivity. The two primary goals of pond dynamics research are characterizing the soils at five PD/A CRSP research sites (Honduras, Peru, Kenya, the Philippines, and Thailand) as well as at non-CRSP sites in Ecuador and Brazil and examining the changes in organic matter and nutrient concentrations and availability over time. The results will be used to develop a pond soil classification system similar to that used in terrestrial soils. The information on changes in nutrient availability over time and site soil characteristics will be especially relevant to pond fertilization studies and practices.
The following Ninth Work Plan investigation continued into the current reporting period:
Note: The schedule for 9PDR2 was modified. The revised schedule appears in the Addendum to the Ninth Work Plan.
Members of the CRSP Pond Dynamics project visited several countries to collect soil samples for their research. Boyd, Wood, and Thunjai visited the University of the North, South Africa. Together they collected pond soil cores at three sites and discussed possible future collaboration with Koos Prinsloo, Johan Theron, and Andrew Scholtz of the Aquaculture Program at the University of the North. Boyd and Thunjai also visited Centro Nacional de Acuicultura e Investigaciones Marinas (CENAIM/ESPOL) in Ecuador on a separate trip where they collected pond soil cores from three ponds at one site. Boyd traveled to Thailand 13 to 25 June 2001 and visited an aquaculture site to observe bottom soil management techniques. He also visited inland ponds with low-salinity shrimp culture to observe environmental conditions in the ponds' vicinity and discuss with Mali Boonyaratpalin of Kasetsart University and Sidthi Boonyaratpalin of the Thailand Department of Fisheries. Finally, Greg Whitis traveled to Brazil 8 to 15 July 2001 where, with the assistance of Julio Queiroz of EMBRAPA, he collected pond soil samples from three ponds on a fish farm. Queiroz reciprocated by visiting Auburn University for four weeks and helping with analyses of soil samples collected in Brazil in June 2000.
Boyd presented data from the CRSP project (Water Quality Monitoring in Honduras) at workshops in Choluteca, Honduras, and Managua, Nicaragua. The workshops were funded with USDA Hurricane Mitch Recovery Funds, but nearly all of the data discussed were collected by CRSP researchers in Honduras. The workshops were held on 5 to 12 February in Honduras and 26 February to 6 March 2001 in Nicaragua.
During the year, a total of fourteen commercial aquaculture concerns contacted Boyd about soil information from CRSP research. This group consisted of six companies from Ecuador, two companies from Guatemala, one each from Colombia, India, Saudi Arabia, and Thailand, and five US companies.
Boyd presented a lecture on 1 August 2000 to the Ministry of the Environment at Muscat, Oman, on best management practices in aquaculture. He later presented a lecture on water and soil quality to faculty and students at Centro Nacional de Acuicultura e Investigaciones Marinas (CENAIM), San Pedro, Ecuador, on 24 May 2001.
Boyd used material from CRSP-related research in teaching the course "Water and Sediment Quality Management in Aquaculture" at Auburn University during fall of 2000. Two lectures were devoted to findings from the CRSP.
Boyd presented a workshop on inland shrimp farming to an estimated 250 farmers in Guayaquil, Ecuador, on 28 and 29 May 2001. PD/A CRSP soil data were an important aspect of the presentation.
Sonnenholzner, S. and C.E. Boyd, 2000. Managing
the accumulation of organic matter deposited on the
bottom of shrimp ponds Do chemical and biological
probiotics really work? World Aquaculture, 31(3):2428.
Thunjai, T., 2001. Pond soil pH measurement. M.S. thesis, Auburn University, Alabama.
Thunjai, T., C.E. Boyd, and K. Dube, 2001. Pond soil pH measurement. Journal of the World Aquaculture Society, 32(2):141152.
Boyd, C.E. BMPs in aquaculture. Presented to
AquaMexico at Culiacan, Mexico, 57 October 2000.
>Boyd, C.E. BMPs in aquaculture. Presented to the Fourth Latin American Aquaculture Congress and Exhibition at Panama City, Panama, 2528 October 2000.
Boyd, C.E. Best management practices (BMPs) for pond aquaculture. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
Boyd, C.E., J. Clay, and J. Hargreaves. Codes of conduct for improving environmental and social performance in shrimp farming. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
Sonnenholzner, S. and C.E. Boyd. Chemical and physical properties of shrimp pond bottom soils in Ecuador. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
Thunjai, T., C.E. Boyd, and W. Wood. Vertical profiles of bulk density, total carbon, total nitrogen, and total phosphorus in pond soil cores. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
Wood, W. Perspectives on use of best management practices in agriculture. Presented to Aquaculture America 2001 at Orlando, Florida, 2125 January 2001.
AquaMexico at Culiacan, Mexico, 57 October 2000. (Boyd)
International Aquaculture Conference at Panama City, Panama, 2528 October 2000. (Boyd)
Aquaculture America 2001 at Orlando, Florida, 2125 January 2001. (Boyd, Wood)
PD/A CRSP Annual Meeting at Orlando, Florida 26 January 2001. (Boyd, Wood)
C.E. Boyd was selected as the Butler/Cunningham Eminent Scholar in Agriculture and the Environment at Auburn University.
Soil cores were taken from ponds in Thailand, Honduras, Kenya, Peru, Brazil, and the Philippines. All cores could be delineated into F, S, M, T, and P horizons without difficulty. The major similarities among cores involved an increase in dry bulk density and a decrease in concentrations of total carbon, total nitrogen, and total sulfur with increasing depth into the sediment. There was wide variation in acidity, phosphorus, major cation and micronutrient concentrations, pH, texture, and color in samples from different sites, but differences in these variables with sediment depth did not follow clear trends. The S horizon, the main sediment layer that interacts with pond water quality, varied in thickness from 2 to 10 cm. Pond management should focus on neutralizing acidity and enhancing organic matter decomposition within the S horizon through liming and drying of pond bottoms between crops. Sediment accumulates in deeper parts of ponds over time, and soft sediment should be removed periodically.
Results of sediment analyses were used in formulating a pond soil classification system based on levels of primary and secondary sediment properties. The primary properties are pH, texture, sediment thickness, and organic matter status (mineral or organic in nature). The secondary properties are organic carbon, carbon:nitrogen ratio, acidity (exchangeable acidity and acidity from sulfide oxidation), carbonates, and sodium adsorption ratio. Two optional, tertiary properties, thickness of F horizon and oxidation status of the sediment surface, may be used in the classification system if desired. The classification system is described in this report.
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