Volume 37 (2017): Issue 332 (July 2017)

Legume seed inoculation prior to sowing is a well-known practice in agriculture. Nitrogen fixation, due to the symbiotic relationship between legumes and rhizobia, improves the productivity of legumes. Rhizobia strain specificity can be observed very often, leading to differences in the total protein content. In this study two faba bean cultivars (‘Karmazyn’ and ‘Bartek’) and five pea cultivars (‘Retrija’, ‘Zaiga’, ‘Lāsma’, ‘Vitra’ and ‘Bartek’) were tested using various rhizobia strains. In addition, strain effectivity was observed in four different soil types. Overall, the protein content increase was observed after seed inoculation with Rhizobium sp. Rhizobia strain and plant cultivar interaction specification was observed. Plant cultivar appeared to have a decisive role in the formation of protein content when inoculated with Rhizobium sp. From these pilot experiments, it can be concluded that, when choosing Rhizobium sp. strains for legume inoculation, soil type also should be considered. Rhizobia has the potential to be used as a commercial preparation intended for increasing legume protein content, alongside with increased legume yield; however, different rhizobia strains should be mixed together to achieve the optimal result.

Production economics forms a very important part of an enormous range of economic theory. Agricultural production is no exception. When evaluating the competitiveness of the multifunctional agriculture, it is necessary to use the measure of efficiency instead of productivity. The conception of the efficiency is explained and the methods for measurement are provided. The authors discuss the methods of Stochastic Frontier Approach (SFA), Free Disposal Hull (FDH) and Data Envelopment Analysis (DEA) that are particularly useful for multi-criterial evaluation of multifunctional processes. Those methods assign an efficiency score to each Decision Making Unit (DMU) based on how well it transforms a given set of inputs into outputs. Most studies have only focused on application of DEA method for assesment of the efficiency of agriculture farms. There is still a need on applications for sectors. This paper provides an examination of the applicability of DEA method to agriculture sectors efficiency measurement. By applying mathematical models, which are based on the DEA, the efficiency of agriculture in each EU country was evaluated.

In the article “Professor Tinbergen’s Method” (Keynes J. M. Professor Tinbergen’s Method. − The Economic Journal. 1939. Vol. 49. No. 195) John Maynard Keynes expressed critical notes concerning insufficient scientific level of the Jan Tinbergen’s results obtained with the help of econometric methods. The conclusion of present research is that the critical appraisal of econometric applying given by John Maynard Keynes in 1939 can be completely assigned to many published in Latvia research in economics and business done by inductive statistics because scientists carelessly apply the linear regression model in absence of the knowledge a priori required by proper theorems and algorithms. Moreover, many times there is no sense even to speak about stochastic experiment because the most important condition − ceteris paribus does not fulfil, namely, economic environment is not homogeneous enough. As the result, the causal inferences derived from Regression Report are not scientifically justified. The second conclusion is that the objective criticism in econometrics applications area in order to keep the satisfactory level of scientific correctness and scientific ethics in Latvia has to be established. We also assert that the applications of inductive econometrics in agriculture are much more justified due to possibility to repeat the stochastic experiments many times in constant circumstances like in physics and mechanics. The meta-target of present article is to remind the protests of John Maynard Keynes to the careless utilization of econometric theorems and to raise a wide discussion about the problems of correctness in applying inductive statistics in economics and agriculture in Latvia.

Nitrogen management strategy in plant growth period based on chlorophyll content evaluation in plant can improve nitrogen usage efficiency and reduce environmental contamination. This study is aimed to determine the impact of different nitrogen and sulphur fertilizer rates on dynamics of chlorophyll content in winter wheat during vegetative growth and to determine the relationship between nitrogen and chlorophyll content and grain yield of winter wheat. Field trial involving a winter wheat (Triticum aestivum L.) variety ‘Kranich’ was conducted at the LUA Research and Study Farm Vecauce during a three-year period (2012-2015). The treatments were 0, 85, 153, 175+S21, 175 (in 2015), 187 N kg ha⁻¹ and different nitrogen norms according to chlorophyll meter Yara N-tester (Konica Minolta Ltd.) data: 180, 150, 205 N kg ha⁻¹ depending on the year. The results of the trial show that the maximum chlorophyll content in different plant parts was observed at the end of flowering stage. The chlorophyll content depended on the level of mineral fertilisation. The highest chlorophyll content in leaves, stems and ears was obtained by using additional sulphur in two trial years. Usage of chlorophyll meter Yara N-tester obtained the highest chlorophyll content in all analyzed plant parts in one trial year. Chlorophyll content was significantly dependant on plant growth stage in stems in all trial years, in leaves in two trial years, and in ears in one year. Nitrogen fertilization significantly affected chlorophyll content in leaves and stems in one trial year. Close positive correlation was observed between grain yield and wheat plant chlorophyll content and average nitrogen concentration at the end of flowering stage in all three trial years.

The growth data and the potential returns from 15-year-old plantations of pine Pinus sylvestris L. (6 trial sites), spruce Picea abies Karst L. (9 trial sites) and silver birch Betula pendula Roth (13 trial sites), established in abandoned agricultural lands in a variety of soil types (sod calcareous, anthrosols, podzolic, podzols, gley, podzolic gley, alluvial), using the planting density 2,500 and 3,300 and also 5,000 trees/ha are analysed.

For tree plantations in agricultural soils (alluvial sod-gley, gley-sod podzolic, sod-podzolic gley, typic podzol) at the survival of 80-98% the stock volume for 15-year pine is as high as 102-155 m³ha⁻¹ with the volume growth 5.72-8.94 m³ha⁻¹ per year; the same indices for spruce in agricultural soils (gley sod-calcareous, sodpodzolic, cultivated, sod-podzolic gley, alluvial sod-gley, base-unsaturated brown) are 75-98 m³ha⁻¹ and 10.26-15.76 m³ha⁻¹, respectively. For 15-year plantation birch the mentioned indices may vary from 61 to 169 m³ha⁻¹ and from 7.54 to 29.82 m³ha⁻¹ per year. The lowest volume growth (4.66 m³ha⁻¹ per year) is for birch in heavy clay soil (gleyic sod-podzolic), the highest (29.72-29.82 m³ha⁻¹ per year) – in cultivated soils and pseudogley soil.

Plantation cultivation of pine, spruce and birch in agricultural lands may by the age of 15 years yield with a profit such forest products as pulpwood, fire wood and woody biomass. The gross income gained from first commercial thinnings of plantation pine, utilizing pulpwood, fire wood and logging residue biomass, may vary from 679-2267 EUR ha⁻¹, for spruce the same indices are 1644-3272 EUR ha⁻¹, for birch - 683-2188 EUR ha⁻¹.

The decreasing number of the Lithuanian residents has strong impact on the educational system: the number of pupils is decreasing, the schools are getting closed. School is considered to be the provider of educational services, so it is necessary to search, how to preserve and attract clients – pupils. The growing competition induces search for distinctiveness among the schools. According to the theory of generations of William Strauss and Neil Howe, now we have to educate representatives of generation Z, who do not like violence, restrictions, want to be distinctive and are open to the world of technologies. The teacher faces the challenge when s/he wants to convey mathematical skills to these pupils. The profile teaching followed by training based on individual curricula provided more choices for the pupils. This freedom led to the dead-end of mathematical literacy and forced to return to a compulsory national final exam of Mathematics and to change the indexes for the persons entering studies of the first cycle and integrated studies. In the article, mathematics achievements and situation in schools in Lithuania as well as the measures taken to improve mathematical literacy in the country are described.