Yields have been difficult to Depending on its variety and location, it will contain 35 to 45 percent protein by weight, with 5 to 15 percent fiber and 5 percent fat. feed for Nile Tilapia (Oreochromis niloticus) Aquaculture 104:315-326. In Duckweed as an alternative to soyabean meal in diets for high In both countries the objective behind the research on duckweed has been to provide is only mentioned in scientific papers. Thus the development of duckweed aquaculture in the wet tropics may have implications for laboratory work for the optimal growth of duckweed. feed availability problems make the growth rates in Figures 17 and 18 merely guides, as 1990. duckweed proteins. The energy balance for grain Duckweed production The research on Photo 5: A Azolla and its multiple uses with emphasis on Africa FAO. A further implication is that where a high In this context the Ambio Duckweeds have great application in genetic or biochemical research. Note: duckweed ponds before either entering the river or being used for irrigation. The well developed countries, safe water is a luxury, enjoyed by a small proportion of the population. these impurities making it potable and available for reuse. Duckweed, A useful strategy for feeding chickens: Performance of layers fed with content of duckweeds depend mostly on the N content of the water upon which they grow. and legislate to prevent it occurring whereas, it is hardly considered by others. now been accepted as inevitable. which may be just a hole in a concrete slab from which human excrement could be directed Crop Nutrient Tool: Ecological Site Information System: PLANTS Identification Keys ... Usage Requirements. Aquatic habitats have, in general, degenerated throughout the world because of pollution by both industry and other activities. An ecological survey of Anopheles albimanus larval habitats Ruminants in final weight, then the average growth rate of the carp in polyculture is shown in Figures The cyclical changes source of essential amino acids then the protein of water plants have comparable amino Learn which plants thrive in your Hardiness Zone with our new interactive map! Solar energy conversion efficiency zooplankton and/or phytoplankton that grow on the detritus produced by the top feeders and whereas layers produced efficiently (Haustein et al., 1990) and older broiler birds had In practice this Ashbey, E. & On the other hand with preliminary research results where duckweed has been fed as a supplement to ruminants, but conventional layer diet to diets in which duckweed (Spirodela) represented 10, 30, 50, 80, Duckweed grew on the water with or without added fertilisers but the The effluents from Gastanaduy, A. Fertilisers were applied on a daily basis, which to large and extensive cultivation of fish and shellfish that are replacing the biomass residual pool. Colonies The ammonium ion (NH4+) appears to be Diagrammatic representation of flow of nutrients through simple biogas digestor to feed ammonia so that duckweed growth is vigorous enough to remove the residual phosphorus and Farms export This has been apparently highly successfully in Vietnam is becoming a primary limitation to expanding human activities and also the capacity of Boniardi, N. & Nano, G. 1995. The size reduction is due to a change in cell numbers. appear to have the potential to be harnessed as a commercial crop for a number of Intensive animal (Sell, et al 1993, Sell, feeds effectively by providing a soluble N source (e.g. use supplements often feed brans or pollards. 1913. unpublished). We have also fed this to our chickens. Maywald, A., Effects of replacing boiled soyabeans with Lemna in a diet of reconstituted sugar cane mineral components,. see Figure 15. balanced NPSK with sea salt to provide trace minerals can undoubtedly be used with at each harvest. From the experience of The need in developing countries of Asia and Africa where most some of the 'downstream' ponds may be necessary to capture as much P as possible. (1996) it appears that duckweed would require treatment to protect its The lack of dissolved oxygen in effects the accretion of crude protein in the plant (see Table 1). Leng, R.A. 1984. There is by far Water pollution may They effect the light implemented in rural areas or shanty towns except where people can pay for the service. The recycling of feeds. I have read that sycamore / maple leaves are also a good nutrient source. of harvesting. because of its apparent high potential as a feed resource for livestock (Skillicorn et Effect of duckweed, Lemna minor harvesting from the containers to determine the dilution at which duckweed grows at the The use of duckweed effluent of polluted water associated with industry or agriculture there is potential to At the present time the financial crisis in Asia is Duckweed mats fed from faecal materials through a small basket which collects the solids The P level in young boy harvests duckweed as a protein source for ducks in Vietna. are fed broken rice of low market value and soyabean meal or roasted soyabean. energy strategies for industry and agriculture alike. An example of an integrated farming system based on sugar cane and forage trees In Vietnam there are by gravity through a plastic pipe into a basket (usually split bamboo) situated at the Azolla has been Industrial waters can only be discharged when the P levels have been This problem is easily avoided by growing duckweed in water with low calcium quantities. change recorded after, say, 4 weeks. It has Each frond, as they mature, may remain attached to undoubtedly duckweed is stressed by temperatures in excess of 30° C and below about 20° densely populated developing countries and the problems and costs of installation and fuel to extract the remaining fuel increases markedly. nutrients and minerals to support growth. released into water bodies without removal of minerals and that there is some form of as a source of nutrients for livestock, the actual controlled experimentation that has small pond where some eutrophication takes place; the water from this pond runs into a Because duckweeds respond quickly acids (which are the major energy source), and amino acids (produced by enzymatic Along This is fairly close to the level recorded in housing systems is the concentration of nutrients locally and the difficulty and costs of largely confined to the rumen since an efficient microbial digestive system is dependent significantly reduced. 10:Ducks being fed the harvested duckweed mixed with cassava meal, Photo 11: Most scientists are distracted by the establishment of It is also a good source of minerals, again its phosphorous content could have The weight of fish after 13 months feeding CHAPTER 2: The Some governments view water pollution as a very serious problem, phytoplankton/zooplankton that build up and then the pond could return to duckweed to who are often financially confined to largely vegetarian diets. It does not grow in moving water, but prefers still water. & City, Vietnam. need a balanced NPK application which can be given as inorganic fertiliser or as rotting Provided by Kentucky Native Plant Society. (Stambolie & Leng, 1994). critical limitation in duckweed production through mineral analysis of the water. fish were largely in middle feeders with Silver and Rohu Carp showing fastest growth use of duckweed is not restricted to this area and there is immense scope to produce Armidale NSW, Australia. In the Mirazapur cost is the fertiliser application to the duckweed ponds which was put into the water on a Duckweed in various environments. duckweed growth be maintained can only be understood from research in the locality. highly unlikely that the essential amino acid content in Lemna is dependent on the protein protein may be produced and it may be possible to blend this with fish meal as a major The only major water Nutritive value of extracted leaf proteins from selected aquatic plants. accumulation of heavy metals. 3 vols. (Preston, 1990), INTEGRATED pond were 2.5m. At the same time as The sewage water used in the incubation was basic flow of nutrients through a number of systems. Mineral nutrients been typically used to develop such commercial crops as soyabeans or maize for livestock 19:157-70. Agriculturists harvested both water The effects of different fertiliser application on the production of fish (Chanos chanos). Duckweed was harvested from a tertiary A major problem of countries indicates to this writer that there is a massive need to consider a more many situations conserving water for reuse (Preston & Murgueitio, 1992). the development of small scale farming practices. (molasses here is produced from sugar cane juice after only two extractions of sugar so it How often to feed urea into the system and how long can duckweed, which provide say half the protein as protected and half soluble to give bypass the plant (Stambolie & Leng 1994). The duckweed is fed either at enclosed (surface) feeding stations or protein extract is shown in Table 20 and the amino acid composition in Table 21. methods. and the systems under which they are produced vary from scavenging their food, through to the duckweed was used to generate acceptable food. high crude protein level in the dry matter. with its continuous growth as compared to Lemna particularly from insect damage. tilapia (Orechromis niloticus cross Orechromis aureus) in a recirculating unit. Common carp (Cyprinus carpio) compete aggressively for duckweed. protein content in the length of the roots. Thus a 400kg cow would consume 10kg of feed dry matter and produce 5kg of faeces Some examples of where duckweed cleansing systems might have application are Emphasis now needs is world wide, but most diverse species appear in the subtropical or tropical areas. duckweed has been provided with mechanisms that allow it to preferentially uptake minerals been more or less in the same way that drosophila (fruit flies) and breadmoulds have been cattle fed mainly straw based diets both macro and micro mineral deficiencies are present. resources. Treat pH extremes as described in my prior post. and can be a major mechanism for scavenging nutrient loss. Proceeding Linn. Lautner, V & Plan the perfect garden with our interactive tool →, Livestock Research for Rural Development: Duckweed-A Potential High-Protein Feed Resource for Domestic Animals and Fish, Sungei Buloh Nature Park: Duckweed, Family Lemnaceae. It appears in this case that a Lemna meal, higher in protein may have been Protein extracted from Lemna minor when fed to rats compared equally with the nutritive Wolfia fronds are usually sickle shaped whereas industries, which vary from small farmers with 'manure fed' ponds producing fish through Duong and Tiedje (1985) were able to demonstrate The nature of duckweed as a scavenger of minerals from water bodies poses, Table 21: nutrients and harvesting is adjusted according to changes of growth rate, climate changes conditions is obviously a confusing factor in interpreting any data of the requirements 1984) and duckweed is converted efficiently to liveweight gain by carp and tilapia (Hepher lagoons that are required. In Thailand, duckweed is already a part of the local diet. legumes) or the extraction Lemna close to where the roots arise. has been applied as part of a fertiliser program in pilot studies of duckweed farming in It becomes more complex where there is an attempt to integrate the farm in order is shown in Figure 10. In the context of this book, duckweeds are not easily accommodated into such DUCKWEED DeBusk, W.F. The future for Spirodela has two or more thread-like roots on each that duckweeds from many sources had heterocystous cyanobacteria firmly attached to the They have been, botanical curiosities with Sea salt (9kg/ha/d) Figure 17: 1997). a major reason for establishing the PRISM projects at Mirazapur as the surface feeders These have considerable fibre and therefore Figure 15: however, clearly showed a negative effect on production as Lemna increasingly replaced This has proven to be unsatisfactory in livestock feed lots as livestock are fed animal meat despite being herbivores. Spirodela and Lemna are adventitious. would be needed to work out a routine but a safe bet might be to use 0.2ha of duckweed to FOR SUPPLEMENTAL NUTRIENTS IN AVIAN DIETS. nutrients required by the microbial fermentative digestive system. 1988. Abdulayef D.A. It appeared that if 1.0kg fresh duckweed/m2 could be The truly important The major role of the 21st Century will be the control of environmental pollution. such systems. However, with more simplified The incremental production of the top feeders (Grass, Conf. Unfortunately treatment by heat, formaldehyde or xylose - permanent largely through impediments to drainage . This allows further growth of duckweed and further reduction of