خيارات البحث
النتائج 1131 - 1140 من 2,185
Treatment of domestic wastewater by natural means
2007
Askinis, S., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
On the basis of this research and the investigations of other authors (1992 - 2002), the paper presents the comparison of the treatment efficiency of domestic wastewater treatment facilities functioning by different natural means. From all the studied three natural wastewater treatment facilities, constructed wetlands are considered as most efficient for domestic wastewater treatment: here the removal of organic pollutants and biogenic compounds is 85-98% and 67-95% respectively. Biological ponds are most suitable for the treatment of domestic wastewater, the discharge and pollution of which is fluctuating within a wide range. However, such ponds do not always ensure the treatment until the allowable rates. Their treatment efficiency according to biochemical oxygen demand (BOD5) is 49.6%. Total nitrogen amount contained in wastewater outflow from the treatment facilities with biological ponds was on the average 22.2 mg lE-1. The biggest problem of those ponds is rather low P removal efficiency (only 29.5%). Therefore wastewater flowing out of the ponds needs additional treatment. The usage of subsoil filtration fields is limited because their arrangement requires light soils. When arranging the distribution pipeline below the freezing zone, in many places the requirement that the pipes must be 1 m above the maximum ground water level is violated. The pipes should be arranged in places where there is no recipient for treated wastewater outflow. The load of subsoil filtration fields should not exceed 300 m**3 haE-1 per month. From the economical point of view, domestic wastewater treatment facilities with flowing ponds require least expenses.
اظهر المزيد [+] اقل [-]The effect of slurry application on the quality of ground water
2007
Miseviciene, S., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
The paper deals with the analysis of ground water quality when slurry is applied on crop rotation fields. The investigations were carried out in Juodkiskis study object of the Lithuanian Institute of Water Management in 1995-1998. According to the average concentrations, the quality of ground water samples taken from the borehole arranged in Juodkiskis test field was good compared with hygienic rates for drinking water. All samples taken for the estimation of ammonia and nitrate nitrogen amount were of good quality. However, nitrate-N concentration increased to 5.5-5.6 mg lE-1 in some periods. Having compared actual phosphate phosphorus concentrations with the allowable ones it may be confirmed that ground water is not polluted with phosphates as phosphate phosphorus concentrations did not reach P-load permissible for drinking water. Considering the correlation connection between ground water level and chemical compounds concentrations, it was determined that ammonia nitrogen and phosphorus compounds concentrations were influenced by ground water level fluctuations (correlation coefficient r = 0:54 and r = 0:62). (Given r values correspond to the reliability criterion tactual is greater than ttheor95%). Lower ground water levels in a borehole determine higher N - NH4**+, P - PO4**- and Ptotal concentrations. No relation between nitrate nitrogen (N - NO3**-), Ntotal and K**+ and ground water level fluctuations was determined.
اظهر المزيد [+] اقل [-]Social capital in Pieriga region, [Latvia]
2007
Igaune, E., Latvia Univ. of Agriculture, Jelgava (Latvia)
At rural enterprises, besides the traditional resources - natural, financial, and human capital - there is some other kind of capital - it is social capital. Foreign scientists have done a lot of researches on it. The nature of social capital and its role in economics is not much studied in Latvia. The present scientific article reflects consumptions on social capital by different foreign scientists. The World Bank as an institution has also approached to the research of social capital. It studies social capital at institutions. The World Bank describes the social capital of two kinds. The scientific article characterizes Pieriga region. Rural enterprises and businessmen of agricultural, industrial and service branches in Pieriga region have been enquired. By the results of the enquiry, the presence of social capital in rural enterprises and its impact on their development have been analysed.
اظهر المزيد [+] اقل [-]Use of redworms (Perionyx excavatus) to manage agricultural wastes and supply valuable feed for poultry النص الكامل
2009
Vu, Dinh Ton | Han Quang, Hanh | Nguyen, Dinh Linh | Nguyen, Van Duy
peer reviewed | Perionyx excavatus, cultured in Vietnam in early 1990s, showed an important role in managing organic wastes and supplying a very nutritious feed for animals. To develop vermiculture in practice, four treatments of different substrates including 100% fresh cattle manure (CM); cattle manure + pig manure in 50:50 ratio (CPM); cattle manure + pig manure + rice straw in 50:40:10 ratio (CPMRS) and pig manure + rice straw in 90:10 ratio (PMRS) were prepared to examine worms’ growth and their decomposition efficiency. All substrates were composted 45 days before feeding to worms. The result showed that cattle manure (CM) was the best substrate for worm growth (biomass gained 713 g after 45 days or 242.6% of growth rate). The worm biomass achieved in CPMRS and PMRS treatments was significantly lower than that in CM treatment. As compared to primary substrates, vermicomposts exhibited an excellent result with a great increase in the amount of total P (0.3 – 0.6%), total K (0.09 – 0.23%), Ca (0.51 – 0.79%) and a decrease in N-NH3 and N-NH4+. A study was carried out to evaluate the influence of feed supplemented with worms on the growth and meat quality of broiler chickens (n=148). Starting at 4 weeks old the chickens were divided into a control group and three experimental groups corresponding to worm levels in the diet of 1, 1.5 and 2% on a dry matter basis according to a completely randomized design. Chicken fed the diet supplemented with 2% worms had the highest live weight at 10 weeks (1925 g/head vs 1823 g/head for the control). Percentage of breast and leg meat was also higher than in the control group. Chickens in the three worm groups had better FCR. The different levels of red worm supplementation did not affect meat quality (pH, color, and the rate of dehydration after storage and processing).
اظهر المزيد [+] اقل [-]Fermenting rice straw with the fungus Pleurotus eryngii increased the content of crude protein and the digestibility of the straw
2019
Huyen, Nguyen Thi | Le, Nguyen Thi Tuyet | Tuan, Bui Quang
The objective of this experiment was to determine the digestibility of rice straw fermented for 28 days with the fungus Pleurotus eryngii. Four Phan Rang sheep with body weight of 20.5 kg (±0.42 kg) were allocated to a changeover design with three treatments (consecutive periods each of 20 days). In period 1 the diet was 100% of guinea grass (1:GG); in the second period it was 30% FTR + 70% GG (2:FTR); in the third period it was 30% RS and 70% GG (3:RS:GG). In each period, the first 14 days were for adaptation to the diet followed by 6 days of measurements of feed intake and digestibility. The growth of the fungus reduced the content of NDF, ADF and ADL, enhanced the content of crude protein (from 4.2 to 7.1% in DM), and the digestibility of DM (from 43 to 53%) and of the crude protein (from 45.8 to 54.4%). Over the 28-day treatment period, 14.8% of the straw biomass was catabolized.
اظهر المزيد [+] اقل [-]The effect of essential oils of tagetes minuta and tithonia diversifolia on on-host behaviour of the brown ear tick rhipicephalus appendiculatus
2018
Wanzala, W. | Hassanali, A. | Mukabana, W.R. | Takken, W.
On-host behaviour of Rhipicephalus appendiculatus was studied in the field in Bungoma County in Kenya to evaluate the putative repellent effects of essential oils of Tagetes minuta and Tithonia diversifolia at its predilection feeding site. Oils of both plants caused a disruption of orientation, movement and attachment behaviour of ticks. More ticks dropped off in the treatments with the two essential oils than with the control. Treating the ear pinna with the essential oil of T. minuta caused the highest percentage of ticks to drop off the host body. No tick reached the ear pinna treated with the essential oil of T. minuta and up to 30% of ticks (from the forehead release site) reached the ear base. When the ear pinna was treated with the essential oil of T. diversifolia, one tick reached the ear pinna and up to 40% of ticks (from the dewlap release site) reached the ear base. The results show that T. minuta repels ticks more strongly than T. diversifolia. However, both essential oils offer possibilities for exploitation of potentially effective and environmentally acceptable tools for on-host tick control.
اظهر المزيد [+] اقل [-]Livestock intensification and use of natural resources in smallholder mixed farming systems
2013
Samdup, T. | Udo, H.M.J. | Viets, T.C. | Zijpp, van der, A.J.
Bhutan aims to intensify livestock production not only to improve livelihoods of farming households and to meet the increasing demands of livestock products, but also to sustainably use natural resources. This paper assesses the impact and trends of livestock intensification on the use of Common Property Resources (CPR), and how this affects the cattle numbers that can be maintained and the nitrogen (N) and phosphorus (P) flows at the farm. Data on household, cropping and livestock activities were collected through interviewing 183 households in extensive, semi-intensive, intensive, and intensive peri-urban areas in the years 2000 and 2004. In the extensive and semi-intensive areas, CPR was the most important source of Total Digestible Nutrients (TDN) for cattle. In the intensive areas with a majority of crossbred cattle, the farmers relied less on CPR than in the other two areas, but still about one quarter of the TDN requirements were met by grazing CPR. Grazing in the CPR provided the highest proportion of NP inputs at farm level; without grazing on CPR all four areas would have had highly negative soil nutrient balances. Intensification of livestock production through crossbreeding has not resulted in major reductions in cattle numbers per farm, but it is contributing to reduced use of CPR by farmers. Intensification partly replaces farm nutrient flows from CPR with nutrient inputs through increased use of concentrates, conserved fodder, and fertilizers. More awareness of nutrient management is required among farmers coupled with more research on nutrient assessments.
اظهر المزيد [+] اقل [-]A cross-sectional survey on fasciolosis in selected settlements of Taveta Division, Coast Province, Kenya النص الكامل
2012
Mungube, E.O. | Sila, D.M. | Kariuki, C.W. | Bauni, S.M. | Tenhagen, B.-A. | Wamae, L. | Nginyi, J. | Omondi, G.A.
A cross-sectional survey on fasciolosis was conducted in March 2009 in Taveta Division. Bura Ndogo, Challa, Kiwalwa, Kitogoto and Lake Jipe Gicheha settlements participated in the study. A total of 338 (197 cattle, 111 goats and 30 sheep) faecal samples from 42 herds were examined using the sedimentation technique. Similarly, husbandry practices and aspects of herd owner education in the same settlements were captured using a standard questionnaire. Selective deworming targeted at the sick and /or weak looking animals was done by some herd owners interviewed. Fasciolosis prevalence in cattle, goats and sheep was 25.9%, 23.4% and 33.3%, respectively. Extensive grazing and age stratum 7 - 12 months were identified as potential fasciolosis risk factors with the latter being significantly (p<0.05) associated with the disease. On the contrary, home watering, training on livestock husbandry practices and deworming were significant (p< 0.05) protective factors of fasciolosis. Improved husbandry practices assisted by the selective anthelmintic treatments targeting the young animals were identified as feasible fasciolosis control options for Taveta division. In conclusion, the results of the study have clearly shown that fasciolosis is widespread in Taveta Division making it necessary for further longitudinal studies on the disease for establishment of an effective control programme
اظهر المزيد [+] اقل [-]Influence of male or female headship on the keeping and care of small ruminants: the case of the transitional zone of Ghana
2011
Duku, S. | Price, L.L. | van der Zijpp, A.J. | Tobi, H.
The study was undertaken in the Ejura-Sekyedumasi District of Ghana to investigate how household headship characteristics and labour availability relate with the household’s decision to keep and spend time on small ruminants. Key informants were interviewed prior to a census of all the 407 households in two villages, to collect demographic, crop, and livestock data, which was used in bivariate and logistic regression analyses. A subsequent time use study involved a stratified sample of 24 households, and the t- test was used to compare households. In general, female-headed households (FHH) were of lower socio-economic status, and had fewer adult household members and less livestock, compared to male-headed households (MHH). The final logistic regression model had a 77.1% success rate in predicting households keeping small ruminants, with socio-economic status and sex of the household head, presence of poultry and the number of active adults as significant predictors. Characteristics of FHH that kept small ruminants were not significantly different from their male counterparts, but the former spent less time feeding their animals. The odds of keeping small ruminants were ultimately 2.1 times higher for male-headed households. The low socio-economic status of most FHH with less labour availability is a disincentive for small ruminant rearing
اظهر المزيد [+] اقل [-]Rangeland dynamics in South Omo Zone of Southern Ethiopia: Assessment of rangeland condition in relation to altitude and Grazing types
2010
Terefe, A. | Ebro, A. | Tessema, Z.K.
A study was undertaken in Hamer and Benna-Tsemay districts of the Southern Ethiopia with the objective to determine the condition of the rangelands for grazing animals as influenced by altitude and grazing types. The rangelands in each of the study districts were stratified based on altitude and grazing types. In the study districts, a total of 32, 3, 2, 7 and 29 species of grasses, legumes, sedges, other herbaceous plants and woody species were identified, respectively. The common and/or dominant grass species in the enclosures was Cenchrus ciliaris while in the communal grazing areas they were Cynodon dactylon and Tetrapogon tennulis. In riverside grazing areas, the common and/or dominant grass species was Cynodon dactylon. The total grass biomass of communal, riverside and enclosure areas found in the different altitude categories of the study districts ranged from 398-503; 98-626, and 1,132 – 1,209 kg/ha, respectively. The common and/or dominant woody species in the communal grazing areas were highly palatable species of Acacia tortilis and Grewia bicolor and less palatable Solanum species. In riverside grazing areas, the common and/or dominant woody plants were species of Acacia tortilis, Grewia bicolor, and Solanum species while in the enclosures; Acacia brevispica and Acacia tortilis were found. The woody vegetation density per hectare of communal, riverside and enclosure areas in the different altitude categories of the study districts ranged from 2,501-3,021; 2251-3,021, and 201-700,wd/ha respectively which showed that the communal and riverside grazing areas were bush encroached. The range condition scores ranged from 17.87-20.38 (communal), 22-27 (riverside), 31.05-31.2 (enclosures) which were poor, fair and good condition classes, respectively. Similarly, with regard to the same variable the scored varied from 22-32.87, 19.73-31.43, 17.97-31.44 and 17.87-31.28% in altitudes >1550m, 1250-1550m, 900-1250m, and 550-900m, respectively. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangelands. The result indicated the need for rangeland improvement measures in communal and riverside grazing areas, in order to attain sustainable livestock production from these areas. Establishment of community based enclosures was found to be one of the ways to improve the condition of the rangelands
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