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The lichenoindicative evaluation of oak woodland key habitats
2007
Straupe, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Donis, J., Latvian State Forestry Research Inst. Silava, Salaspils (Latvia)
This article presents the description of oak woodland key habitats and their importance in the maintaining of biodiversity as well as a necessity of management and monitoring. The lichens Lichenes and its percental cover features have been described. The exposition of lichen species depending on the cardinal points has been analysed. The article presents the characteristics of ecological indicators of lichens in the objects. The lichenoindicative evaluation and comparison of oak woodland key habitats in Latvia have been carried out.
Показать больше [+] Меньше [-]Improvement of the parameters of the constructed wetlands filter when applying it for the treatment of dairy wastewater
2007
Askinis, S., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
The objective of the studies was to evaluate the suitability of sand reed filter for the treatment of wastewater from milk collection post and on the basis of the studies performed to determine the minimal length of filtration path in order to reach the normative wastewater treatment level. In 2003, in Padargupiai village (Ariogala municipality, Raseiniai district) experimental treatment facilities for wastewater from milk collection post were constructed. As the pollution of such wastewater after pre-treatment (primary treatment) is 2 times higher than that of domestic wastewater, the filtration path in constructed wetlands was made 2 times longer (up to 10 m long). On the basis of the study results the dependence equations were made, with the help of which the amounts of the main pollutants contained in wastewater of milk collection posts were calculated, after the wastewater is filtered through the sand layer of different length. As calculations have shown, the treatment of wastewater from milk collection posts until the allowable rates depends on the constructed wetlands with the length of the filtration path of 7 m. The removal of organic pollutants, total nitrogen and total phosphorus from wastewater flowing through such media are 97.2%, 68.7%, and 91% respectively. The studies performed allowed to improve the calculations of the necessary area of constructed wetlands in order to reach the normative treatment level of wastewater from milk collection posts according to the index biochemical oxygen demand (BOD5).
Показать больше [+] Меньше [-]Maintanance peculiarities of polder systems in Lithuania during the last decade
2007
Bastiene, N., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst. | Saulys, V., Lithuanian Univ. of Agriculture, Kaunas (Lithuania). Water Management Inst.
Basing on the economic, ecological and social points of view, the polder systems in the Nemunas lowland are considered as unique, requiring a great deal of annual state subsidies. According to the land-improvement programme, during the period of 2006-2008, Lithuanian polder system are planned to be yearly granted 2.15 million euro from the State budget, whereas the local administration of Silute district, which is exploiting the polders of the Lower Nemunas - more than half of the sum (63%). The article includes the analysis of exploitation expenses and statistical estimation of the Lower Nemunas' polders during the period of 1996-2006 as well as the investigation of the funds distribution on routine repairs, reconstruction and maintenance work. The average annual expenses on the pump stations, dikes, ditches and roads during the research period were determined. The analysis of the previous decade's expenses shows that the statistical average of the expenditure on the polder systems of Silute district amounts to 0.68+-0.13 million euro a year. The yearly renovation of polders depreciation should be obviously awarded a grant of the amount not less than 0.72 million euro.
Показать больше [+] Меньше [-]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.
Показать больше [+] Меньше [-]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.
Показать больше [+] Меньше [-]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.
Показать больше [+] Меньше [-]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.
Показать больше [+] Меньше [-]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. | Zijpp, van der, 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
Показать больше [+] Меньше [-]Optimisation of breeding schemes for litter size, lambing interval, body weight and parasite resistance for sheep in Kenya
2011
Verbeek, E. | Kanis, E. | Bett, R.C. | Kosgey, I.S.
The current study optimised breeding schemes for litter size (LS), lambing interval (LI), body weight (BW) and gastrointestinal parasite resistance for sheep in Kenya. Selection for the breeding goal traits was performed in a conventional way using information on phenotypes only. For gastrointestinal parasite resistance, information on genetic makers was used, with faecal egg count (FEC) as an indicator trait. Selection for parasite resistance was partly based on field measurements and the possibilities for marker-assisted selection (MAS) were explored. Several selection schemes were defined based on whether a classical selection only was used (Latin number 1), a quantitative trait loci (QTL) for FEC was assumed to be available (2), that the correlation between FEC and BW was assumed to be positive (unfavourable-Roman I) or negative (favourable- II) and finally how FEC was included in the index (i.e., no inclusion (A), with FEC (B) or with FEC QTL (C-F)). The schemes with overlapping generations were evaluated using the computer program SelAction. Rams, ewes and total selection responses in US dollars ($) per animal, and rams' and ewes' accuracies for each scheme with a favourable or unfavourable correlation were estimated. The differences in total selection responses between schemes that did not include FEC in the selection index resulted in a response of $0.16 in scheme 1AI and $0.20 in scheme 1AII. In schemes 1BI and 1BII, FEC was included in the index. The responses in scheme 1BI and 1BII were $0.165 and $0.217, respectively. The increase in response in schemes II compared with schemes I was due to a favourable correlation between BW and FEC. The different FEC index traits had a different effect on economic response. It should be noted that increased emphasis on selection for FEC will reduce the relative responses to the breeding goal traits BW, LS and LI. Consequently, the goal of selection for FEC should be to maintain acceptable levels of gastro-intestinal parasite resistance as well as sufficient improvement of LS and BW.
Показать больше [+] Меньше [-]Effect of sun-dried and fresh cassava leaves on growth of Tilapia (Oreochromis niloticus) fish fed basal diets of rice bran or rice bran mixed with cassava root meal Полный текст
2010
Chhay, T. | Borin, K. | Sopharith, N | Preston, Thomas R. | Aye, Tin Maung
The growth response of Tilapia fish (Oreochromis niloticus) to supplementation with fresh or dried leaves of a sweet variety of cassava was studied in 1 m deep ponds (each 4 m * 2.5 m * 1 m). Rice bran or rice bran mixed with cassava root meal was provided as the energy source (20-24% of feed DM), the mixed feed being given at the rate of 5% of fish LW. There were 30 fish per pond with average initial weight of 6 g per head. The treatments were arranged as a 2*2 factorial in a Completely Randomized Design (CRD) with 4 replicates. The first factor was cassava leaf processing (sun-dried or fresh); the second factor was energy source (rice bran or rice bran mixed with cassava root meal). The cassava leaves and roots were from a local “sweet” variety traditionally planted by farmers for human consumption. The experiment was conducted for 100 days. Daily gain in weight and length, and the ratio weight: length after 100 days of growth, did not differ among treatments. All the fish survived and there was no evidence of HCN toxicity. Water quality parameters were not affected by the treatments. There were no interactions between sources of protein and of energy. It is concluded that the feeding of cassava leaves with rice bran can be readily adopted by small scale farmers as both these feed resources are readily available in rural areas.
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