Aquaculture-agriculture Systems Research Articles

Nutrient Optimization and Computerized Decision Support Program in Recirculating Integrated Aquaculture System

There are many research activities to improve sustainable aquaculture and agriculture production in the wide world. Sustainable aquaculture is referred to as production of aquatic commodities through farming activities with social, economic and environmental sustainability. A series of experiments were conducted to compare different inorganic and organic fertilizers to improve production of Macrobrachium rosenbergii and to make a decision support program in an artificial sustainable aquaculture-agriculture system. Simply, nutrient wastes from culture tanks were used to fertilize hydroponics or terrestrial plants production via irrigation water. The sustainability and success functioning of the whole system were involved to manage and optimize the use of supplemented minerals, diet and desirable environment for each compartment (prawn, plant and microorganisms).The first experiment was made to evaluate the tolerance of M. rosenbergii in different levels of inorganic fertilizer (EC) formulated in nutrient film technique (NFT) vegetable production system. Results of the first experiment indicated that desirable growth rate of M. rosenbergii was obtained using 0.1 to 0.5EC of supplemental liquid fertilizer. High concentration of potassium (117-177 mg l-1), ammonia (0.72-1.05 mg l-1) and copper (0.04-0.06 mg l-1) inhibited the growth rate of M. rosenbergii in integrated culture system. The second experiment was carried out to assess the effects of different nutrient and stocking density on different population of M. rosenbergii in polyculture system. A different range of inorganic and organic fertilizer was used in the polyculture of plant and freshwater prawn species. Overall results indicated that essential concentration of nutrients, source and M. rosenbergii stocking density have played a major role in the effectiveness of suitable range of minerals in integrated production system. The results also demonstrated that 0.5 EC liquid inorganic fertilizer was not suitable to provide optimum nutrients and chicken manure is still an important fertilizer even in indoor integrated culture system. Finally, a comparative study was conducted to evaluate the optimum level of chicken manure and formulated inorganic nutrients in an artificial integrated culture system. The results indicated that high density culture of M. rosenbergii juveniles (380-400 individual m-2) in fiberglass tanks is possible by the installation of artificial substrate and controlling of nutrient concentration in system. Moreover the addition of aeration tank significantly improved the quality of water (DO and pH) and freshwater prawn growth (1343.0 g/tank) in recirculated polyculture system. The application of 70 g m-3 chicken manure alone encouraged growth of benthic and periphyton algae in culture tanks. The overall observation illustrated the desirable combination of supplemental liquid fertilizer and chicken manure is essential to obtain best growth for each compartment in sustainable polyculture system. A visual expert program (IAAS) was adopted to improve managing and develop technical operation in an artificial integrated culture system. The operation of the polyculture system required the specific knowledge, developing and application of computer systems to excellent operation, control of water quality variables, dissolved nutrients and feed to avoid the production of toxic substance and increase self efficiency and sustainability of the culture system. The accuracy of IAAS expert program was evaluated by polynomial and linear regression techniques through additional experiment. The comparison of results (yield and survival) in expert and real culture system represents higher variation of survival, prawn and plant yields in abnormal culture system. Moreover the evaluation processes demonstrated succeed performance of IAAS expert program in prediction results of optimized integrated culture system (with low variation). In aquaculture, the success estimation of production depends largely on the state of physical and chemical parameters which define optimal culture conditions.

Ten-year simulations of organic matter concentrations in tropical aquaculture ponds using the multiple pool modeling approach

The accumulation rate of organic matter has been used to develop guidelines on sediment management in tropical aquaculture ponds. However, there is conflicting evidence as to the rate of sediment organic matter accumulation and whether steady state concentrations are achieved in the short term (<10 years) in aquaculture ponds. A simulation study using the multiple pool modeling approach (Multi-G model) was conducted to determine the long-term dynamics of sediment organic matter and to establish whether steady state concentrations could be achieved in tropical aquaculture ponds. The Multi-G model, which recognizes the existence of different organic matter pools, each with its own decay rate constant was run as a sub-model of an integrated aquaculture–agriculture system (IAAS) model. The simulation study was conducted for representative management scenarios for new integrated ponds receiving artificial feed, chicken manure, or a combination of chicken manure and crop wastes. The model was run for 10 years using a 0.125 day time step, and each year's simulation consisted of a wet and a dry season, and fallow periods between crops that totalled 121 days for the year. Pond sediment organic matter concentrations increased over time for all input regimes in the following order: chicken manure×plant waste >chicken manure >artificial feed. Simulated organic matter concentration decreased in the first 4–5 years in ponds receiving chicken manure and artificial feed. Contrary to predictions of models that used a single decay rate constant for the organic matter, steady state sediment organic matter were not achieved within the first 5 years of production. These results were consistent with those obtained from long term sediment organic matter experiments in tropical aquaculture ponds. The results show that the multiple pool modeling approach may be more applicable to the simulation of pond sediment organic matter dynamics than those that assume organic matter to consist of a single pool decaying at a single rate.

Aquaculture–agriculture systems integration: an Australian prospective

The concept of integrating aquaculture with irrigated farming systems was evaluated in three projects in the Goulburn–Murray Irrigation District (GMID) in south‐eastern Australia. (1) Semi‐intensive cage culture trials using silver perch, Bidyanus bidyanus (Mitchell), were undertaken in a range of irrigated farming systems: irrigation supply channels; groundwater supplies; and on‐farm storage dams. Survival and growth of fish under these conditions were comparable to fish reared in conventional aquaculture ponds. However, poor water quality at some sites reduced survival and growth. (2) A study was undertaken to assess the feasibility of the cage culture of silver perch and rainbow trout, Oncorhynchus mykiss (Walbaum), in three irrigation water storage reservoirs. Conditions within each reservoir, particularly water quality, wind and wave action, and cage fouling, varied considerably, and influenced fish growth and survival. (3) Mariculture trials were undertaken in two saline groundwater evaporation basins, which were part of an integrated agriforestry and salt reclamation system. The species tested included two oyster, two prawn and nine fish species. Some species exhibited exceptional survival and growth rates under trial conditions. These projects indicate that the concept of integrating aquaculture with existing irrigated farming systems has the potential to enhance productivity, water use efficiency and overall environmental sustainability in the GMID.

Benutting van landbouneweprodukte en gesuiwerde rioolwater in akwakultuur in ontwikkelende gebiede van Suid-Afrika

The serious shortage of potable water supplies for domestic, agricultural and industrial requirements necessitates an investigation into the optimal utilization of this scarce commodity in South Africa. The multipurpose use of water in agriculture through its effective utilization in integrated aquaculture-agriculture food production systems is one way of optimising the application of such water. In the present series of investigations, agricultural wastes such as chicken, cattle and duck manure were applied as organic nutrient in freshwaterfish ponds with and without supplementary feeds. Fish used in polyculture production for the optimal utilization of the various trophic levels in manured fishpond ecosystems included the European and Chinese carp species and the sharptooth catfish. Supplementary food consisted of 18-45% protein fish pellets. As an alternative to organic manures, treated sewage effluent with fish pellets was used to evaluate its fish-production potential. Fish species used in monoculture and polyculture production included the European common carp and the sharptooth catfish. The role of water temperature on the fish-production potential of these systems was also investigated. The possible value of integrated aquaculture-agriculture systems in protein production in rural community development in South Africa is discussed.

The mulberry dike-carp pond resource system of the Zhujiang (Pearl River) Delta, People's Republic of China: I. Environmental context and system overview

Although not well understood scientifically, integrated and diversified aquaculture-agriculture systems have a history of some two millennia in parts of South and Southeast Asia. With the extremely limited farm area and scanty resources available to the typical small-scale farmer of these regions, integrated agro-ecosystems, based on generations of empirical knowledge, provide a balanced diet and often a small marketable surplus for poor rural households, while continuously recycling nutrients and energy through the system, producing little waste, and maintaining a local ecological balance. Despite the few scientific data available on such systems, they are being widely advocated for use in developing countries with no prior experience of integrated farming. This paper (paper I) describes the environmental context and provides an overview of the mulberry dike-polycultural carp pond resource system of Leliu Commune, in the Zhujiang Delta of the People's Republic of China, where complex and highly productive integrated farming systems are operated on a geographical and economic scale unmatched elsewhere. Subsequent papers will focus on the human ecology of the dike-pond system, the ecological basis for system integration, and the results and implications of experiments and trials for increasing the productivity of and the economic rate of return from the system.