FERTILISATION STRATEGIES ACROSS EUROPE: CURRENT SITUATION, POTENTIAL AND LIMITS FOR A HARMONISED APPROACH

Peer reviewe

Decision support system for agricultural land use and fertilisation optimisation: a case study on barley production in Estonia

The success of the decision support systems, developed within GIS with application of different models, depends on the quality of initial data and the models themselves as well as on the possibilities of their linking. The aim of the present study was to analyse the application of different agro-economic models in a computer-based decision support system, developed for optimisation of agricultural land use and fertilisation, on the example of barley production of Kullamaa rural municipality in Estonia. The algorithms used in the agronomical models were obtained from the regression analysis of numerous field experiments. The calculated new agronomical values serve as a basis for the application of economic models. GIS and modelling remain as two separate systems with the capacity for information exchange between them. Profitability of barley cultivation varied in a very broad range in the study area. The optimal fertiliser amounts established for each field allow increasing crop productivity in the region and at the same time preventing environmental pollution due to production intensification. The proposed decision support system can be further supplemented by several agro-economic models and implemented throughout Estonia.

Efficiency of Estonian grain farms in 2000 2004

The aim of this study is to analyse the efficiency of Estonian grain farms after Estonias transition to a market economy and during the accession period to the European Union (EU). The non-parametric method Data Envelopment Analysis (DEA) was used to estimate the total technical, pure technical and scale efficiency of Estonian grain farms in 20002004. Mean total technical efficiency varied from 0.70 to 0.78. Of the grain farms 62% are operating under increasing returns to scale. Solely based on the DEA model it is not possible to determine optimum farm scale and the range of Estonian farm sizes operating efficiently is extensive. The most pure technically efficient farms were the smallest and the largest but the productivity of small farms is low compared to larger farms because of their small scale. Therefore, they are the least competitive. Since pre-accession period to the EU, large input slacks of capital have replaced the former excessive use of labour and land. This raises the question about the effects on efficiency of the EUs investment support schemes in new member states.

Decision support system for agricultural land use and fertilisation optimisation: a case study on barley production in Estonia

The success of the decision support systems, developed within GIS with application of different models, depends on the quality of initial data and the models themselves as well as on the possibilities of their linking. The aim of the present study was to analyse the application of different agro-economic models in a computer-based decision support system, developed for optimisation of agricultural land use and fertilisation, on the example of barley production of Kullamaa rural municipality in Estonia. The algorithms used in the agronomical models were obtained from the regression analysis of numerous field experiments. The calculated new agronomical values serve as a basis for the application of economic models. GIS and modelling remain as two separate systems with the capacity for information exchange between them. Profitability of barley cultivation varied in a very broad range in the study area. The optimal fertiliser amounts established for each field allow increasing crop productivity in the region and at the same time preventing environmental pollution due to production intensification. The proposed decision support system can be further supplemented by several agro-economic models and implemented throughout Estonia.

Effects of an In-Frame Deletion of the 6k

The alphaviral 6k gene region encodes the two structural proteins 6K protein and, due to a ribosomal frameshift event, the transframe protein (TF). Here, we characterized the role of the 6k proteins in the arthritogenic alphavirus Ross River virus (RRV) in infected cells and in mice, using a novel 6k in-frame deletion mutant. Comprehensive microscopic analysis revealed that the 6k proteins were predominantly localized at the endoplasmic reticulum of RRV-infected cells. RRV virions that lack the 6k proteins 6K and TF [RRV-(Δ6K)] were more vulnerable to changes in pH, and the corresponding virus had increased sensitivity to a higher temperature. While the 6k deletion did not reduce RRV particle production in BHK-21 cells, it affected virion release from the host cell. Subsequent in vivo studies demonstrated that RRV-(Δ6K) caused a milder disease than wild-type virus, with viral titers being reduced in infected mice. Immunization of mice with RRV-(Δ6K) resulted in a reduced viral load and accelerated viral elimination upon secondary infection with wild-type RRV or another alphavirus, chikungunya virus (CHIKV). Our results show that the 6k proteins may contribute to alphaviral disease manifestations and suggest that manipulation of the 6k gene may be a potential strategy to facilitate viral vaccine development. IMPORTANCE: Arthritogenic alphaviruses, such as chikungunya virus (CHIKV) and Ross River virus (RRV), cause epidemics of debilitating rheumatic disease in areas where they are endemic and can emerge in new regions worldwide. RRV is of considerable medical significance in Australia, where it is the leading cause of arboviral disease. The mechanisms by which alphaviruses persist and cause disease in the host are ill defined. This paper describes the phenotypic properties of an RRV 6k deletion mutant. The absence of the 6k gene reduced virion release from infected cells and also reduced the severity of disease and viral titers in infected mice. Immunization with the mutant virus protected mice against viremia not only upon exposure to RRV but also upon challenge with CHIKV. These findings could lead to the development of safer and more immunogenic alphavirus vectors for vaccine delivery.Office of the Snr Dep Vice Chancellor, Institute for GlycomicsFull Tex