Three-year Cycles Research Articles

Trends in the livestock and pork market in Poland with regard to the environmental impact of this production direction

After joining the European Union, the market economy continued to drive structural changes in meat production and processing. Unfortunately, the functioning of meat markets was impacted by several threats with significant adverse influence. Phenomena such as the spread of ASF disease, the United Kingdom's exit from the European Union or the Covid-19 epidemic added instability to the already cyclical pork market. The study aims to evaluate the functioning of Poland’s pork market and to identify the main trend in this market. Livestock and pork meat production in Poland form a significant economic sector; however, it creates considerable environmental challenges. The study focuses on key aspects such as greenhouse gas emissions, water usage, feed consumption, and waste management. The study covers the years 2004-2021, i.e., the period of seventeen years after Poland's accession to the European Union. The statistical data analysis methods showed four to three-year cycles in pork live stock with a decreasing amplitude over time and high and relatively stable domestic demand for pork. This provides a favourable foundation for future production direction. However, the systematic changes in the structure of meat consumption and price development led to a steady increase in the share of poultry meat at the expense of pork and bovine during the observed year span.

Association of Vitamin E and Cognitive Decline in Older Adults with and without the APOEɛ4 Allele: A Biracial Population-Based Community Study.

The association of different types of tocopherols (vitamin E) with cognition might vary by the APOEɛ4 allele status. We examined the association of dietary tocopherols with cognitive decline among participants with and without the APOEɛ4 allele over a median of 12 years. 2,193 participants from the Chicago Health and Aging Project were included in the analyses. Global cognition was assessed in three-year cycles. We used a 144-item FFQ to assess dietary intakes of tocopherols and hME Sequenom mass-array platform to assess APOE genotype. We used linear mixed effects models to examine the relationship between tocopherol from food sources and global cognitive decline. The mean baseline age was 74.1 (SD = 5.9) years. Among APOEɛ4 carriers, participants in the highest quintile of intakes of dietary vitamin E had a slower cognitive decline of 0.022 SDU (95% CI: 0.000, 0.043) compared to those in the lowest quintile. A higher intake of dietary α-tocopherol from food sources only was associated with slower cognitive decline in APOEɛ4 carriers (p for trend 0.002) but not among the non-carriers (p for trend 0.937). Among APOEɛ4 carriers, those in the highest quintile of intake of α-tocopherol had a 16.4% slower rate of decline of global cognition compared to those in the lowest quintile (β= 0.034, 95% CI: 0.013, 0.054). Individuals consuming high α-tocopherol from food sources had slower cognitive decline among APOEɛ4 carriers. In older adults, different forms of vitamin E might moderate the relationship of APOEɛ4 with global cognition.

Individuals’ Behaviors of Cone Production in Longleaf Pine Trees

The sporadic cone production of longleaf pine (Pinus palustris Mill.) challenges the restoration of the longleaf pine ecosystem. While much has been learned about longleaf pine cone production at the stand level, little information exists at the tree level regarding cone production and energy allocational strategy. This study aims to analyze cone production and diameter growth of approximately ten sampled longleaf pine trees at seven sites across the southeastern USA over the past twenty years. The results indicate that three-year cycles dominated the cone production dynamics, but longer cycles (four years and more) also occurred. The dynamics of entropy in cone production varied among trees. Taylor’s law, which describes the correlation between average and variance, existed in cone production for the majority of trees. Lagged cone production at one and two years was not autocorrelated among trees across sites. No significant relationships existed between tree diameter (or basal area) growth and cone production among trees across sites. This study provides new information on cone production at the individual tree level and narrows down the possible mechanisms. The results will be helpful in developing strategies for the management and modeling of longleaf pine cone production.

The Evolution of Primary and Secondary School Teacher Standards in China: Analysis of Policy Texts from 1978 to 2022

The primary and secondary school teacher standards are an effective tool for a country to select, evaluate and train primary and secondary school teachers which are clearly stipulated in teacher qualification, evaluation and education policies. Therefore, the structure and evolution logic of primary and secondary school teacher standards can be clarified by text analysis. Based on the text analysis of the main teacher policy texts in China from 1980 to 2022, it is found that the primary and secondary school teacher standards are composed of six basic elements which are political ideology, teacher morality, education and teaching skills, professional knowledge, educational background, physical and mental health, and four core elements which are educational concept, personal moral, curriculum ability and lifelong learning. The structure of it is constantly optimized and the content of it is constantly enriched. The evolution can be divided into three stages: 1980 to 1999, 2000 to 2007 and 2008 to 2022. The first and third stages are characterized by obvious three-year cycles, and the second stage is a smooth transition. Educational realities are the direct basis for evolution of teacher standards while education reform events and educational institutions indirectly impact the teacher standards.

Student achievement trajectories in Ontario: Creating and validating a province-wide, multi-cohort and longitudinal database.

Longitudinal data that tracks student achievement over many years are crucial for understanding children's learning and for guiding effective policies and interventions. Despite being Canada's most populous province, Ontario lacks such large-scale and longitudinal data on student learning. Linking datasets across cohorts requires rigorous linkage protocols, flexible handling of complex cohort structures, methods to validate linked datasets, and viable organizational partnerships. We linked administrative data on early child development and educational achievement and merged two datasets on characteristics of students' neighborhoods and schools. We developed a linkage protocol and validated how the resulting database could be generalized to Ontario's student population. Two main individual-level data sources were linked: 1) the Early Development Instrument (EDI), a school readiness assessment of all Ontario public school kindergartners that is administered in three-year cycles, and 2) Ontario's Educational Quality and Assessment Office's (EQAO) math and reading assessments in grades 3, 6, 9, and 10. To compensate for their lack of a common personal identification number, a deterministic linkage process was developed using several administrative variables. A school-level and a neighborhood-level dataset were also later linked. We examined differences between unlinked and linked cases across several variables. We successfully linked 50% of the EDI's 374,239 cases, 86,778 of which contained all five datapoints, creating a database tracking achievement for multiple cohorts from kindergarten through grade 10, with covariates for their development, demographics, affect, neighborhoods, and schools. Analyses revealed only negligible differences between linked and unlinked cases across several demographic measures, while small differences were detected across a neighborhood socioeconomic index and some measures of child development. In conclusion, we recommend the filling of key voids in sustainable research capacity by creating representative data through linkage protocols and data verification.

Multi-Criteria Assessment of the Economic and Environmental Sustainability Characteristics of Intermediate Wheatgrass Grown as a Dual-Purpose Grain and Forage Crop

Kernza® intermediate wheatgrass [IWG; Thinopyrum intermedium (Host) Barkworth & Dewey] is a novel perennial cool-season grass that is being bred for use as a dual-purpose grain and forage crop. The environmental benefits of perennial agriculture have motivated the development of IWG cropping systems and markets for perennial grain food products made with Kernza, but the economic viability and environmental impact of IWG remain uncertain. In this study, we compared three-year cycles of five organic grain production systems: an IWG monoculture, IWG intercropped with medium red clover, a continuous winter wheat monoculture, a wheat–red clover intercrop, and a corn–soybean–spelt rotation. Economic and environmental impacts of each cropping system were assessed using enterprise budgets, energy use, greenhouse gas (GHG) emissions, and emergy indices as indicators. Grain and biomass yields and values for production inputs used in these analyses were obtained from experimental data and management records from two separate field experiments conducted in New York State, USA. Grain yield of IWG averaged 478 kg ha−1 yr−1 over three years, equaling approximately 17% of winter wheat grain yield (2807 kg ha−1 yr−1) over the same period. In contrast, total forage harvested averaged 6438 kg ha−1 yr−1 from the IWG systems, approximately 160% that of the wheat systems (4024 kg ha−1 yr−1). Low grain yield of IWG greatly impacted economic indicators, with break-even farm gate prices for Kernza grain calculated to be 23% greater than the current price of organic winter wheat in New York. Energy use and GHG emissions from the IWG systems were similar to the annual systems when allocated per hectare of production area but were much greater when allocated per kg of grain produced and much lower when allocated per kg of biomass harvested inclusive of hay and straw. Emergy sustainability indices were favorable for the IWG systems due to lower estimated soil erosion and fewer external inputs over the three-year crop cycle. The results show that the sustainability of IWG production is highly dependent on how the hay or straw co-product is used and the extent to which external inputs can be substituted with locally available renewable resources. Integrated crop–livestock systems appear to be a viable scenario for the adoption of IWG as a dual-use perennial grain and forage crop.

Glasbena ustvarjalnost v osnovnošolskih učnih načrtih za glasbeno vzgojo v Črni gori in Sloveniji / Musical Creativity in Primary School Programmes for Music Education in Montenegro and Slovenia

Encouraging musical creativity in primary schools in Montenegro and Slovenia is determined by the course programs for music education, according to which music teaching in two countries is realised through three musical activities: performing, listening and creating. The similarities between the two primary education systems are characterised by the nine-year duration of primary school, which is divided into three threeyear cycles. Programme for the course Music Culture in Montenegro, dating from 2003, has been developed in collaboration with Slovenian experts. Thus, creation, as an activity, was clearly defined and has been represented in all the revised and new programs that followed. The aim of this paper was to analyse the representation of creation as an activity through which some of the important goals and learning outcomes are achieved in both general primary education systems. The obtained results show that this activity is more concretely represented in the Slovenian programme, and that a higher level of systematicity in its definition has been achieved. Comparative analysis can also serve as a guideline for future improving the programmes and a clearer definition of what is meant by musical creativity in the teaching of music in primary schools of two educational systems.

DOCUMENTING LARGE ARCHAEOLOGICAL SITES, MANAGING DATA, PLANNING CONSERVATION AND MAINTENANCE: THE HERCULANEUM CONSERVATION PROJECT EXPERIENCE

Abstract. Herculaneum, buried by Mount Vesuvius in AD 79, was only extensively excavated during the twentieth century, revealing a remarkable level of preservation but also fragility of what had survived of this Roman seaside town. By the turn of the century, the conservation challenges, paired with the limited capacity of the authorities to respond, was putting the archaeological site at risk. The Herculaneum Conservation Project (HCP), a public-private project underway since 2001, has helped turnaround this situation with the presence of an interdisciplinary team working all year round alongside the public authority, today the Archaeological Park of Herculaneum. With the site in a more stable condition, HCP's attention in the last ten years shifted to building up knowledge and competencies for the self-sufficiency of the Park authority in the face of core long-term management obligations. A new focus on conservation proposals that meet the site's needs but are suited to public tendering found its maximum expression in planning long-term site maintenance cycles. Through the voices of the practitioners involved, the paper recounts the resources and approaches that have been developed in this regard, in particular the specific GIS module that breaks down the archaeological site into the items to be maintained and their relative importance. This massive register of objects – walls, architraves, doors, frescoes, mosaics, etc. – is the backbone of the three-year maintenance cycles developed by HCP adopting an innovative procurement framework for co-sourcing services and works in Italy, the first of which is now being implemented by the Park. A web-based application accessible by operators on site allows real time transmission of monitoring data and records of site-works underway to the database and GIS platform, satisfying immediate administrative needs and quality controls but also delineating the scope of subsequent maintenance cycles. Technological and management tools, shaped by, and responsive to, the needs of the site and their users (the heritage practitioners involved), have been put at the service of the entire life cycle of programmed maintenance at an urban scale, both administrative and technical aspects. This is part of a wider upward spiral of management improvements for the long-term sustainability of this important archaeological site.

Food hoarding of an avian predator: sex- and age-related differences under fluctuating food conditions

Hoarding behaviour (storing food for a later use) has evolved to reduce starvation risk when resources are scarce. Different age and sex classes often show differences in foraging due to experience, skills or life history strategy, but such differences in hoarding under spatio-temporally varying environmental conditions have rarely been studied in the wild. We studied hoarding behaviour of Eurasian pygmy owls (Glaucidium passerinum) during 2003–2016 in western Finland, where the abundance of their main prey (voles) fluctuates in three-year population cycles. In 14 years, 1056 food stores were found during the hoarding season (Oct–Dec) and 330 pygmy owls were trapped at these stores. The number of stores per individual did not vary in relation to age, sex or vole abundance. Adults (+ 1-year old) had their stores farther apart than yearlings. Both the number of stores per year and the biomass of stored prey items increased with vole abundance. Females and yearlings had larger and heavier stores than males and adults, respectively. The same individuals stored more food as yearlings than as adults. These sex- and age-differences in hoarding indicate that it is not constrained by experience or skills. It rather seems that less-experienced yearlings rely more on stored food than adults. Females may need more food due to their larger size and need to accumulate energy reserves before reproduction. A detailed knowledge of age- and sex-related differences in hoarding behaviour under fluctuating abundances of main foods is fundamental to better understand a population response to climate change and forest management. The hoarding behaviour of animals has evolved to cope with the problem of food limitation. On the basis of 14-year data from pygmy owls, we show that the number of stores per year and the biomass of prey items per store increased with vole abundance in the environment. Adults had stores farther apart than yearlings, and females and yearlings stored more prey items and biomass compared to males and adults, respectively. These results indicate that hoarding behaviour responds to the available main prey abundance and varies with traits such as age and sex. Because different age and sex classes might respond differently to variation in food abundance, due to habitat alterations or climate change, a detailed knowledge of hoarding behaviour can be of particular importance to understand changes in body condition, reproductive success and survival of pygmy owls under changing climate and management of boreal forest.

Impact of management regime and frequency on the survival and productivity of four native tree species used for fuelwood and charcoal in the caatinga of northeast Brazil

The seasonally dry deciduous forest (Caatinga) of northeast Brazil is under intense human pressure, and sustainable use of its tree resources for fuelwood is a pressing concern. An experiment was conducted to ascertain which management techniques (coppicing, pollarding or crown-thinning) permit the highest survival of trees and optimal timber production. Four much-utilised tree species: Croton sonderianus, Mimosa ophthalmocentra, Mimosa tenuiflora and Poincianella pyramidalis (syn. Caesalpinia pyramidalis) were studied at two sites in Pernambuco State. The impact of each harvesting regime was evaluated over a six-year period, with additional variables including wet-season versus dry-season harvesting, and three-year versus six-year harvesting cycles. The best performing tree species varied between sites, with M. tenuiflora providing the highest yields with all treatments at Sertânia and M. tenuiflora and Poincianella pyramidalis at Serra Talhada. The optimal management regime did not vary between species. Crown-thinned trees produced limited regrowth with the lowest mortality rates, and when ultimately coppiced growth appeared to have been stimulated. Pollarding was intermediate and coppicing was the poorest management strategy. Trees which were harvested twice, in both 2005 and 2008, had much lower overall production than those which had only been harvested once in 2008. The highest yields were obtained from crown-thinned trees which were coppiced in 2005 or 2008. Management decisions must consider local environmental conditions in the selection of the tree species used to produce fuelwood, however, the optimal management strategy for high production and low mortality is consistently low impact, infrequent crown thinning. There was considerable difference in the findings between the study sites (e.g. in the distribution of statistically significant results), and also in the impacts of treatments on mortality between the four species. The results can be used to guide species-level management regimes that minimise tree mortality, contributing to long-term fuelwood productivity.

Comparative Analysis of the Nitrogen Effect of Common Agricultural Practices and Rotation Systems in a Rainfed Mediterranean Environment.

The nitrogen (N) effect of legumes is one of the main reasons for their inclusion in rotation systems and their success in rainfed agriculture of Mediterranean areas. The comparative analysis of this effect in relation to alternative systems or practices is essential for a comprehensive appreciation in their merit. This field experiment was comprised of four three-year rotation cycles. Wheat (Triticum turgidum durum) was seeded for two consecutive years after common vetch (Vicia sativa L.), treated in three different ways, and after fallow and compared with three wheat monocultures: the conventional one, the continuous straw incorporation, and the sewage sludge incorporation once every three years. Wheat grain and straw yields and N uptake were compared among treatments. Results showed that rotation systems that included vetch were the most promising for improving sustainability. Maximum N uptake and the greatest yield surpluses were obtained when wheat followed vetch incorporated during flowering. When vetch in the rotation was cut for hay or left to fill grains subsequent wheat showed also enhanced yields. Fallow affected the rotation system’s fertility due to the incorporation of volunteer plants into the soil. Sewage sludge sustained production without the need for inorganic fertilization during three years. Straw incorporation always gave the smallest yields and N harvests, presumably due to soil N immobilization.

Effects of Climate Change on Outdoor Skating in the Bei Hai Park of Beijing and Related Adaptive Strategies

This paper reports findings derived from a study of the impacts of climate change on winter outdoor skating activities in the Chinese park of Bei Hai from 1989 to 2015. Based on field observation data and in-depth interviews, it was concluded that the outdoor skating activities, with a history of more than 1000 years, are being threatened by the warming climate. The opening dates and duration times of skating over the last 26 years showed periodic variations over three-year cycles. Increases of temperatures by 1 °C in December were associated with a 3.80-day delay in the skating-field opening dates and a 4.49-day decrease in the operation duration times. In particular, climate change has resulted in a loss of the skating field area and a reduction in the operation duration times, and tourists are moving north for skating-related recreation or conducting alternative activities. The current adaptive strategies are not very effective.

Effects of different sub-soiling frequencies incorporated into no-tillage systems on soil properties and crop yield in dryland wheat-maize rotation system

No-tillage has become a universal management system to conserve soil water and sustain soil productivity in dryland agriculture. However, no-tillage in a long-term may produce some undesirable soil characteristics. An occasional tillage operation has been used as a mean to manage some of the defects that have emerged in NT farming systems. This study was to explore the effect of sub-soiling at different frequencies in a no-tillage farming system of an annual cropping system of winter wheat-spring maize rotation on Loess Plateau. The study consisted of three tillage practices: NT (no-tillage were applied every year), NT/ST (no-tillage were applied in first year and rotated with sub-soiling in second year), NT/NT/ST (no-tillage were applied in first two year and rotated with sub-soiling in third year). The study began in 2007 on a former spring maize field with conventional tillage and lasted for three-year rotation cycles by 2016. In ten years, for the soil physical properties, NT/ST rotation significantly decreased soil bulk density, and increased soil porosity and amount of macroaggregates (>0.25mm) when compared to NT (P<0.05). For water storage, NT with ST rotations (NT/ST & NT/NT/ST) increased the soil water storage in the fallow periods. Moreover, NT/ST rotation produced higher average grain yields, WUE and economic profit in the winter wheat-spring maize cropping system when compared to NT over the ten years. However, the soil organic matter (SOM) and total N under NT with ST rotations (NT/ST & NT/NT/ST) were lower than it for NT. For this long-term experiment, NT provided a better soil nutrient condition, NT/NT/ST and NT/ST rotation showed a better effect on soil water storage in fallow. For the comprehensive productivity, NT/ST rotation showed a balanced soil properties and crop production effect among three tillage treatments. In the winter wheat-spring maize cropping system, NT/ST rotation enhanced soil physical and chemical properties and increased yield and water holding capacity of soil. We predict that the NT/ST rotation will be of great significance in promoting the development of rain-fed conservation farming in the Loess Plateau of China.

Diversity of parasitic fungi from soybean cyst nematode associated with long-term continuous cropping of soybean in black soil

ABSTRACTThe soybean cyst nematode (SCN) is a major yield-limiting pest of soybean. In this study, experiments were conducted to examine the diversity of parasitic fungi from SCN associated with disease-suppressive soil fields in Northeast China. Soil samples were collected from three fields under different rotation systems that were established in 1991: (1) a continuous long-term cropping field with soybean (SSSS) that had been shown to be SCN-suppressive, (2) cycles of three-year rotation with corn, soybean, and wheat (WCS), and (3) continuous cropping field with three-year cycles of two years soybean and one-year corn (SSC). In the traditional method result, cyst densities of SCN declined as increase of parasitic fungi, and the percentage of parasitic fungi associated with cyst of SCN was higher in SSSS field than other two fields. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) also showed that parasitic fungi of SCN were also increased in SSSS field, compared with the other two fields. Principal component analysis based on PCR-DGGE data revealed that fungal communities on cysts could be divided into three groups: one group occurred in SSSS, and the other two groups were in WCS and SSC fields, respectively. Long-term cropping with soybean monoculture in the black soil field might increase parasitic fungi of SCN. These fungal communities may play an important role in the ecological suppression of SCN in disease-suppressive soil.

Screening of the soybean collection of the national center for plant genetic resources of ukraine for protein and fat contents in seeds

The article presents results of screening of soybean collection accessions of the National Center for Plant Genetic Resources of Ukraine for protein and fat contents in seeds.The aim and tasks of the study. Investigation of polymorphism of soybean collection accessions by protein and fat contents in seeds. Identification of valuable sources for breeding programs aimed at improving biochemical composition of seeds of soybean varieties.Material and methods. The study material was 524 soybean collection accessions. The study was carried out in three-year cycles. The accessions were grown in the field in the collection nursery. Seeds were analyzed for protein and fat contents by conventional techniques.Results and discussion. On the basis of protein and fat contents in seeds of collection accessions, a significant polymorphisms was established. Depending on genotype and geographical origin of accessions, a wide range of variability was observed: for protein content in seeds - from 25.54% to 43.55% and for fat content - from 16.39% to 26.90%. We did not find a close correlation between fat and protein contents in seeds and ripeness group. Within each ripeness group, there are accessions both with low and high contents of these compounds.Conclusions. The wide variation in protein and fat contents in soybean seeds of the collection accessions of the National Centre for Plant Genetic Resources of Ukraine opens great possibilities to use these accessions as starting material for creation of new varieties for different purposes. Valuable sources with high fat and protein contents in seeds and stable expression of these traits, which will contribute to raising the breeding efficiency in this direction.

Correlating the cycle of climate in Beijing with the theory of five-yun and six-qi in traditional Chinese medicine using complex Morlet wavelet analysis

IntroductionTraditional Chinese medicine suggests that climate change is closely associated with the theory of five-yun and six-qi. We explored the correlation between the cycle of climate in Beijing and five-yun and six-qi. MethodsComplex Morlet wavelet analysis was applied to analyze the cycle of five meteorological elements (including temperature, rainfall, relative humidity, vapor pressure, and wind speed) in Beijing from 1948 to 2007, describe central tendency of master cycle, and explore the correlation between master cycle of climate and cycle of yunqi. ResultsNeither the five-year cycle nor the ten-year cycle was found in the annual average of the five meteorological elements. There was a five-year cycle on temperature, vapor pressure and relative humidity at the last stage of qi (in late winter), which was similar with the cycle of five-yun. For all of the five meteorological elements, the three-year and nine-year cycles were found in the third stage of qi (in early summer), and the five-year cycle was observed in the last stage of qi, which does not match the six-year cycle of six-qi according to traditional Chinese medicine theory. A cycle time of 24 or 25 years was found in the climate of Beijing, while the cycle of interaction on five-yun and six-qi was 30 years. ConclusionsThere was lack of sufficient evidence to confirm any relevance between the cycle of climate in Beijing and cycle of whole yunqi system. Further research is still needed to explore such correlations.

Thermophysical and chemical properties of biomass obtained from willow coppice cultivated in one- and three-year rotation cycles

Most of the energy today is obtained from fossil fuels, which are becoming more expensive and less available. Energy from biomass produced on agricultural land is an alternative option. Energy crops should guarantee high yield and good quality parameters, associated with their use in energy production. This study analysed the thermophysical and chemical properties of biomass obtained from 15 new clones of willow selected in the Department of Plant Breeding and Seed Production of the University of Warmia and Mazury in Olsztyn. The plants were cultivated in one- and three-year rotation cycles, run in 2009-2011 at two research stations: in Baldy and in Łezany. The energy content as well as elemental and physical properties of biomass were analysed. The higher heating value was better in biomass from one-year shoots (on average 19.66 MJ kg -1 d.m.). The highest value of this parameter was recorded for the clone of Salix acutifolia UWM 093 (20.04 MJ kg-1 d.m.). The higher heating value in biomass of three-year old clones was on average lower by 0.06 MJ kg -1 d.m. The lower heating value in biomass increased in longer willow coppice harvest cycles. The highest lower heating value was recorded for the clone UWM 035 of Salix pentandra (9.27 MJ kg -1 ) harvested in a three-year cycle, whereas the lowest one was achieved by the clone of Salix dasyclados UWM 155 (7.55 MJ kg -1 ) harvested in a one-year cycle. The average moisture content in three-year shoots was 50.01% d.m., being higher by 2.31% in one-year shoots. The ash content was lower in biomass harvested in three-year rotation. In conclusion, willow biomass obtained in a three-year harvest cycle contains less of undesirable elements and proves to be better quality fuel than biomass obtained in a one-year harvest cycle.

Ocena innowacyjności sektorów polskiej gospodarki

The article includes an assessment of the innovation sectors of the Polish economy &ndash; industry and services, both in terms of their ability to create innovation and effects of the innovative activity. The analysis has an empirical character and based on the results of two recent edition of the survey CIS (Community Innovation Survey) carried out in three-year cycles in EU countries. The results obtained allow us to formulate some proposals to potential directions of development of the Polish economy in the coming years.

No significant differences in soil organic carbon contents along a chronosequence of shrub willow biomass crop fields

Shrub willow biomass crops (SWBC) have been developed and promoted for widespread deployment in northeastern and mid-western US as well as in Europe. There are concerns that the production system could reduce the soil organic carbon (SOC) over time due to soil disturbances and repeated three-year harvest cycles. This study assesses changes in SOC beneath shrub willow (Salix x dasyclados [SV1]) biomass crops utilizing a 0, 5, 12, 14, and 19-year old SWBC fields. The sites' management history was similar, suggesting uniform SOC contents prior to plantation establishment. SOC contents were analyzed by total (i.e. 45 cm) and by layer (i.e. 0–15 cm, 16–30 cm, and 31–45 cm) across different ages. Mean SOC contents to 45 cm depth ranged from 175 to 188 Mg ha−1, and showed no statistically significantly differences across ages (p = 0.15) and no interaction between age and depth (p = 0.19). SOC contents differed significantly with soil depth when averaged across ages (p < 0.0001). Statistical analysis of SOC contents by layer, however, showed that SOC contents in the upper 15 cm depth were significantly different (p < 0.001). Linear contrasts of mean SOC contents for the 0–15 cm depth revealed that the 0-year old was significantly different compared with the 5, 12, 14, and 19-year old SWBC.

Interannual variability of the solar constant

It can be concluded from the calculations performed of interannual variations of the distance between the Sun and the Earth in the moments of the Earth’s position in the equinoctial and solstitial points that the mean amplitude (approximately the same for all the equinoctial and solstitial points) is determined to be equal to 5700 km (at the maximum values being approximately equal to 15000 km). The values of the solar constant have been calculated on the basis of the data of varying distances, and the values of its interannual variability (for the period from 1900 up to 2050) have determined. Based on the analysis of the series, new periodic characteristics of a long-term variation of the solar constant, related to the celestial-mechanical process, namely, to the perturbed orbital motion of the Earth, are obtained. A three-year cycle is distinguished in the interannual variability of the solar constant, which alternates with a two-year cycle every eight and eleven years. The amplitude of the interannual variability in the series of equinoctial and solstitial points is on average about 0.1 W/m2 (about 0.008% of the solar constant value). This is comparable to the interannual variability of the solar constant in the eleven-year cycle of the solar activity. The series obtained can be represented by alternation of eleven-year and eight-year cycles. The eleven-year cycle is composed of three three-year cycles and one two-year cycle, and the eight-year cycle is composed of two three-year cycles and one two-year cycle.