خيارات البحث
النتائج 1 - 4 من 4
Toxaphene contamination in Lake Baikal's water and food web
1993
Kucklick, J.R. | McConnell, L.L. | Bidleman, T.F. | Ivanov, G.P. | Walla, M.D. (Marine Science Program, University of South Carolina, Columbia, SC 29208 (USA))
Bio-accumulation of pesticide residues in water through food chains
1995
Prapassara Pimpan | Juntip Thamrongsiskul | Naunsri Tayaputch (Department of Agriculture, Bangkok (Thailand). Agricultural Toxic Substances Div.)
Qualitative and quantitative analysis of organochlorine insecticide residues were conducted in water, sediment, aquatic plants and animals from 3 freshwater reservoirs. Ninety water samples, 90 sediment samples, 397 aquatic plants samples and 121 aquatic animals samples were collected during March-April and August-September 1989. There were about 14 kinds of aquatic plants, such as water hyacinth, water lettuce, algae and water lilly etc. Aquatic animals are fish, shrimps and snails, but most of them are fish. They are striped snake-head fish, carp and catfish etc. Total samples of 698 were analyzed by using gas chromatographic techniques at Agricultural Toxic Substances Division. The results indicated that 5 kinds of insecticides were found in most samples. They were lindane, heptachlor, aldrin, dieldrin, DDT and derivatives. Dieldrin was detected at higher concentration and found in all samples. The residue level of dieldrin ranged from 0.01-0.12 ppb in water, 0.005-0.036 ppm in sediment, 0.001-0.138 ppm in aquatic plants and 0.001-0.037 ppm in aquatic animals respectively. The accumulation of dieldrin residue in water and aquatic plant samples from all reservoirs are not different but the level of dieldrin residue in sediment samples from Bueng Boraphed is higher than the other 2 reservoris. However the levels of dieldrin residue in sediment, aquatic plant and aquatic animal samples higher than those in water samples respectively.
اظهر المزيد [+] اقل [-]Opportunities and limitations of food - feed crops for livestock feeding and implications for livestock - water productivity النص الكامل
2009
t. amede | m. samad | o. p. singh | m. blümmel
M. Blümmel, M. Samad, O. P. Singh, T. Amede, 'Opportunities and limitations of food - feed crops for livestock feeding and implications for livestock - water productivity', The Rangeland Journal, vol. 31(2), p.207, CSIRO Publishing, 2009 | The paper discusses the contribution of crop residues (CR) to feed resources in the context of the water productivity of CR in livestock feeding, using India as an example. It is argued that crop residues are already the single most important feed resource in many livestock production systems in developing countries and that increasing their contribution to livestock feeding needs to be linked to improving their fodder quality. Using examples from multi-dimensional crop improvement, it is shown that CR fodder quality of key crops such as sorghum, rice and groundnut can be improved by genetic enhancement without detriment to grain and pod yields. Improving crop residue quality through genetic enhancement, agronomic and management interventions and strategic supplementation could improve water productivity of farms and systems considerably. The draw-backs of CR based feeding regimes are also pointed out, namely that they result in only moderate levels of livestock productivity and produce higher greenhouse gas emissions than are observed under feeding regimes that are based on high quality forages and concentrates. It is argued that feed metabolisable energy (ME) content should be used as an important determinant of livestock productivity; water requirement for feed and fodder production should be related to a unit of feed ME rather than feed bulk. The paper also revisits data from the International Water Management Institute (IWMI) work on livestock?water productivity in the Indian state of Gujarat, showing that water input per unit ME can vary several-fold in the same feed depending on where the feed is produced. Thus, the production of one mega joule of ME from alfalfa required 12.9 L of irrigation-derived water in south Gujarat but 50.7 L of irrigation-derived water in north Gujarat. Wheat straw in south Gujarat required 20.9 L of irrigation-derived water for 1 MJ ME and was in this instance less water use efficient than alfalfa. We conclude that water use efficiency across feed and fodder classes (for example crop residue v. planted forages) and within a feed is highly variable. Feeding recommendations should be made according to specific water use requirement per unit ME in a defined production system
اظهر المزيد [+] اقل [-]Isotopes and radiation in agricultural sciences; v.1: Soil-plant-water relationships. - v.2: Animals, plants, food and the environment
1984
L'Annunziata, M.F. (ed.) | Legg, J.O. (ed.)
Includes bibliographies
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