PD/A CRSP Research Reports 02-181 to 02-185

Levee pond design model E.W. Tollner, University of Georgia, Athens, Georgia, USA 15 January 2002, CRSP Research Report 02-181 Abstract The levee pond model is an Excel® spreadsheet that computes a volume balance on a levee pond. The model is organized into the following pages: Directions and overview, table of contents, input, pond model, results and principal spillway. The design is based on answers to 15 key questions on the Input page. Each question has guidance in the form of a comment that becomes visible when clicked upon. The model computes a volume balance on the pond as shown in a drawing on a "Drawings" page. The model is designed to assist competent NGO personnel in helping small to medium producers. After completing the initial inputs, proceed to the "Results" page. Maximum, Average and minimum pond volume changes based on net Inflow and net Outflow are computed. The pump in rate with zero pump out is used to determine the water balance required to satisfy evaporation, seepage and rainfall. One iterates on the pump in rate to achieve the desired near zero target for net outflow volume change. Volume changes based on net outflow should be zero to positive for the pond not to lose volume. Values on the results page are copied from the "Pondmodel" page that shows detailed computations. Most users would not be concerned with the computational details. Volume changes based on net inflow should approach the volume change target set based on the level of management anticipated. After achieving the initial water balance, one adjusts both the pump in and pump out rates to achieve the desired volume change targets. The pump in rate exceeds the pump out rate by the initial volume balance in order to preserve the initial volume balance. Adjust these inputs until the desired volume changes are achieved based on net inflow. One may then proceed to the "Principal SW" page for a pipe-riser spillway design. The intent of the levee pond model is to develop a complete volume balance on a pond with a recirculation target, which may range from 0 to any number of volume changes per month. The recommended procedure is to first set the output pump rate to zero. One may then determine the inflow pump rate necessary to balance seepage, rainfall and evaporation In a given climatic region, based on net monthly net outflow as shown on the "Pondmodel" page. Monthly rainfall and evaporation are used in the monthly balances. Soil seepage is included, which should be determined from a soils analyses or seepage tests. Volume balances on net input should be near zero to have a sustainable pond. Next one may determine the pump out rate and pump in rates to meet the volume change target. This process begins by inputting a trial pump out rate. Input the initial pump in rate determined above, plus the trial pump out rate for the new trial pump in value. The volume balance based on net output should be near the volume change target. Maximum, average and minimum volume ratios are reported, based on monthly ratio computations. The principal spillway design is included. There is no watershed supply; therefore an emergency spillway was not included. If springs or stream flow are not adequate for your desired pond size and management, one may wish to consider a watershed pond or a hillside pond for water harvesting. Another model, "Hondurascatchmentpond" is available for this application. Water harvesting is dependent on diverting runoff from a watershed collection zone to the pond. The design of the watershed pond or hillside pond is very site specific. You are strongly encouraged to consult with a competent pond designer. Ask a local NGO representative for help. Experience suggests that valleys with available springs are the best levee pond candidates. Valleys frequently have soils of adequate clay for sealing purposes. Elevations above 1000 m become problematic for finding springs. In Latin America, there seems to be a correlation between both coffee and rice production with water availability. Areas with nearby hardwood forests tend to bode well for water availability. This abstract is excerpted from the original paper, which was published in D. Meyer (Editor), 6to. Simposio Centroamericano de Acuacultura Proceedings: Tilapia Sessions, 22-24 August 2001. Tegucigalpa, Honduras, pp. 116-117. Training and technical assistance in warm-water fish culture Thomas J. Popma, Department of Fisheries and Allied Aquacultures, Auburn University, Alabama, USA Daniel E. Meyer, Escuela Agricola Panamericana, Zamorano, Honduras 15 January 2002, CRSP Research Report 02-182 Abstract A central issue for aquaculture development in Honduras is fingerling supply. Previous PD/A CRSP research reported that farmers in remote places found that fingerlings were difficult to obtain but did not consider this sufficient reason for withdrawing from fish farming. The Zamorano PI and his technician in this project confirmed that the Comayagua research station "El Carao" was not a reliable supplier of fingerlings for producers. Private fingerling producers are few and generally geared to supply large-scale commercial operations. The overriding objective of our work was to provide technical assistance and training to current and potential fingerling suppliers to small- and medium-scale tilapia producers in Honduras. A Peace Corps program of technical support to fish farmers was possibly the most focused on-farm assistance to small-scale fish farmers in Honduras, but this program ended in 1995. The national extension program in aquaculture has a presence in many regions, but the effort is fragmented and under-funded. A large number of nongovernmental organizations (NGOs) have been active in rural development projects in Honduras, including several promoting fish farming, but expertise in this activity is often insufficient to provide critical technical information required for proper pond management. During November 1999, we consulted with 13 representatives of national and international, government and non-government organizations. From these consultations, a strategy and timetable were developed for implementing technical assistance and training of fingerling suppliers and technicians working with NGOs currently, or potentially involved in small- and medium-scale fish culture development. At least 33 small- and medium-scale tilapia producers (each with 150 - 12,000 m2 of water surface) and 26 restaurants were subsequently interviewed by the technical team to assess the production and marketing demands for tilapia in Honduras. With the collaboration of a local NGO, we invited representatives of NGOs with actual or potential interest in aquaculture development to a one-day seminar to describe opportunities and constraints for family-scale fish culture in Honduras. The Zamorano team continues to identify and provide technical assistance to regional fingerling producers and organizations involved in aquaculture extension. During the life of this activity three technical workshops were provided by Zamorano and Auburn for actual and prospective fingerling producers and extensionists. More than 30 publications on fingerling production and pond management practices have been incorporated in a web-based information system developed by a local NGO, primarily in response to needs of local NGOs. This abstract is excerpted from the original paper, which was published in D. Meyer (Editor), 6to. Simposio Centroamericano de Acuacultura Proceedings: Tilapia Sessions, 22-24 August 2001. Tegucigalpa, Honduras, pp. 118-125. Web-based information delivery system for tilapia for sustainable development of aquaculture in Honduras Brahm P. Verma, Biological and Agricultural Engineering, University of Georgia, Athens, Georgia, USA Daniel Meyer, Department of Biology, Escuela Agricola Panamericana El Zamorano, Zamorano, Honduras Tom Popma, Department of Fisheries and Allied Aquaculture, Auburn University, Alabama, USA Joseph J. Molnar, Department of Agricultural Economics and Rural Sociology, Auburn University, Alabama, USA E. William Tollner, Biological and Agricultural Engineering, University of Georgia, Athens, Georgia, USA 15 January 2002, CRSP Research Report 02-183 Abstract The project was focused on identifying and developing methods to create an enabling environment for sustainable development of aquaculture on Honduras. Honduras has large network of NGOs operating at village level, an exceptional educational institution in Zamorano with commitment to extend training and knowledge in aquaculture and an established in-country sustainable development electronic network operated by Red de Desarrollo Sostenible-Honduras (RDS-HN). We develop the concept of training the trainers (NGOs working with farmers at village level) by bringing together Zamorano and RDS-HN and developing a Web-based Information Delivery System for Tilapia (WIDeST). In this approach WIDeST capture on the developed electronic information technology network and capacity of RDS-HN while providing a means to provide easy to use information developed by Zamorano. Furthermore, it provides a way to connect local NGOs, farmers, decision-makers for exchanging information and enabling them to make informed decisions. The WIDeST provides information on Tilapia production and related topics, natural resources of Honduras, contact information of NGOs, and chat room facilities for conducting virtual forums and discussions. The email facility enables the user to ask questions which is answered by an expert. Since the inauguration session in March 2001, the Website has had more than 6800 hits, and more than 300 individuals formally registered to receive information. The participants at training and workshop sessions have found this to be an easy and useful approach and have provided strong encouragement for adding new information. The number of individuals already reached as evidenced from the numbers of visits to the Website provide a strong evidence that is may be a way to build capacity of local institutions in developing and environment that enables farmers to adopt aquaculture as an alternative in their farms. This abstract is excerpted from the original paper, which was published in D. Meyer (Editor), 6to. Simposio Centroamericano de Acuacultura Proceedings: Tilapia Sessions, 122-24 August 2001. Tegucigalpa, Honduras, pp. 126-134. A sustainable shrimp aquaculture system from Honduras* H.L. Corrales, C.A. Lara, J.E. Heerin, and J.M. Wigglesworth, Grupo Granjas Marinas, Choluteca, Honduras B.W. Green, Auburn University, Auburn, Alabama, USA 15 April 2002, CRSP Research Report 02-184 Abstract Annual global capture fisheries destined for human consumption have leveled off at around 60 million metric tons in recent years. Additional supplies from aquaculture are important to provide for future demand for seafood. Shrimp aquaculture is a relatively new activity that has grown significantly since the 1980s. Compared with development of traditional agriculture practices, there is a great potential for improvement in shrimp cultivation techniques that must come from research and development. Producers, producer organizations, and other development agencies must take a more active role in research activities. A program of field research was established during the last several years to determine and optimize production practices to achieve an environmentally sustainable system in Honduras. To assure sustainability of the activity, water quality trends will guide how much additional production area should be developed based on the elaboration of models to estimate the carrying capacity of individual estuaries. Honduras is a good example of producers, researchers, and government working together to define and optimize sustainable shrimp farming practices. There are substantial improvements to be made in decades to come. Continued support in the areas of water quality, health management, nutrition, and genetics is essential to assure the long-term viability of shrimp farming for producers and the environment. This abstract is based on the original paper, which was published in Sustainability of Agricultural Systems in Transition, W.A. Payne, D.R. Keeney, and S.C. Rao (Editors). ASA Special Publication Number 64, Madison, Wisconsin, pp. 83-95. * Reprints of this paper can be ordered from the PD/A CRSP Program Management Office in hard copy format. Recycling pond mud nutrients in integrated lotus–fish culture Yang Yi, and C. Kwei Lin, Aquaculture and Aquatic Resources Management Agricultural and Aquatic Systems and Engineering Program, School of Environment, Resources and Developmen, Asian Institute of Technology, Klong Luang, Pathum Thani, Thailand James S. Diana, School of Natural Resources and Environment, University of Michigan, Ann Arbor, Michigan, USA 14 November 2002, CRSP Research Report 02-185 Abstract An experiment was conducted in nine 200-m2 fertilized earthen ponds at the Asian Institute of Technology, Thailand, during January–September 2000. This experiment was designed to assess the recovery of nutrients from pond mud by lotus (Nelumbo nucifera), to assess pond mud characteristics after lotus–fish co-culture, and to compare fish growth with and without lotus integration. There were three treatments in triplicate: (A) lotus–tilapia co-culture; (B) tilapia alone; (C) lotus alone. Seedlings (0.39 ± 0.09 kg) of Thai lotus variety were transplanted to ponds of the treatments with lotus (treatments A and C) at a density of 25 seedlings pond–1, while sex-reversed all-male Nile tilapia (Oreochromis niloticus) fingerlings (8.6–10.3 g) were stocked at two fish per square meter in ponds of the treatments with tilapia (treatments A and B) when the water depth had been increased to 50 cm due to increasing lotus height. Ponds stocked with tilapia (treatments A and B) were fertilized weekly with urea and triple super phosphate (TSP) at a rate of 4 kg nitrogen (N) and 1 kg phosphorus (P)/ha/day after tilapia stocking. There was no fertilization in ponds of the lotus alone treatment. Lotus co-cultured with tilapia or cultured alone in ponds was able to effectively remove nutrients from old pond mud. Annual nutrient losses from mud in a 1-ha pond was about 2.4 ton N, and 1 ton P, among which about 300 kg N and 43 kg P were incorporated in lotus biomass. There were no significant differences in lotus growth performance between the lotus–tilapia and lotus alone treatments, while Nile tilapia cultured alone grew significantly better than when co-cultured with lotus. The present experiment has demonstrated the effectiveness of nutrient removal from old pond mud by lotus and the feasibility of rotation and co-culture of lotus and Nile tilapia. Both systems can recycle nutrients effectively within ponds and are environmentally friendly culture systems. This abstract is based on the original paper, published in Aquaculture, 212 (2002):213–226.

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