2021, Vol. 19, No. 4

Selle kollektsiooni püsiv URIhttp://hdl.handle.net/10492/7135

Sirvi

Nüüd näidatakse 1 - 20 31

Biomass ash as a potential raw material for the production of mineral fertilisers
(Estonian University of Life Sciences, 2021) Stankowski, S.; Chajduk, E.; Osińska, B.; Gibczyńska, M.
Ash obtained from biomass combustion could be a valuable product for fertilisation of soil or/and plant. It is connected with high reaction and potassium, calcium, magnesium content as well as low content of heavy metals. The analysed phyto-ash was obtained from Szczecin Power Plant Poland (12.2018–12.2019). The samples of phyto-ash, in the number of 24, were collected on subsequent dates at two-week intervals to determine the total content of the analysed elements (P, K, Mg, Ca, As, Cd, Ni, Cr, Pb, Hg). The differentiated percentage share of macroelements both in total form as well as available form in ash from wood biomass and Agro-biomass is described as: calcium > potassium > magnesium > phosphorus. Phosphorus is characterised by a very low (10%) and highly variable availability. Ash from biomass is characterised by alkali pH (13.0). Biomass ash can be treated as a mineral fertiliser used for soil deacidification and as a substitute for calcium fertilisers. Biomass ash has a high content of potassium and magnesium, which could qualify this by-product as a source for fertiliser. Mean contents of heavy metals: lead, cadmium, arsenic and mercury in ash do not exceed the limit values for the mineral fertilisers. The variable percentage share of Agro-biomass did not result in significant changes in the amount of available form of macro-elements in ash. The obtained results indicate the pronounced variability, depending on the season in a year, of the content of available macroelements in biomass ash.
Storage stability of rapeseed methyl ester stored in a sealed barrel for seven years
(Estonian University of Life Sciences, 2021) Heikkilä, S.; Sirviö, K.; Nuortila, C.; Niemi, S.
Storage stability is one of the main quality parameters related to fatty acid methyl esters (FAME) biofuels. The deterioration of biofuels´ properties during storage is a more serious issue than with conventional fuels. In particular, lengthy storage threatens the oxidative stability of FAME fuels because factors such as the presence of air, elevated temperatures or presence of metals promote the oxidation process. Consequently, the acceptable storage time for FAME fuels is generally regarded to be regrettably short, at no more than six to12 months. However, storage conditions play an important role in determining actual storage stability. This study aimed to investigate and evaluate any deterioration in the quality of rapeseed methyl ester (RME) fuel that has been stored for as long as seven years in adequate storage conditions. The fuel was stored in the dark, contained in a sealed steel barrel in an insulated shipping container outdoors. The temperature of the container varied with seasonal fluctuation, but the fuel never froze during storage. The study analysed six key fuel properties of the RME: ester content; water content; density; kinematic viscosity; oxidation stability index; and acid number. The analyses were conducted immediately after opening the barrel, and again after two months of storage in a laboratory. The results were compared to those measured for the fresh fuel, seven years earlier. The comparison of the results indicate that the fuel quality had suffered no serious deterioration during the seven-year period.
Evaluation of the combining ability of CMS lines in crosses with samples of grain sorghum and Sudan grass
(2021) Kibalnik, O.; Kukoleva, S.; Semin, D.; Efremova, I.; Starchak, V.
The versatility of use, species diversity, and high drought resistance have ensured the demand for sorghum among agricultural crops in the world. Currently, the most promising direction of breeding is the creation of F1 sorghum hybrids, which is based on the identification and selection of parental forms with high combining ability. In this paper, the combining ability analysis crosses of two hybridization schemes: grain×grain sorghum and grain sorghum×Sudan grass was carried out using topcross method. Gene action governing inheritance of a particular trait can be measured in terms of general and specific combining ability estimates, where general combining ability effects are mostly indicative of additive gene action (ms (GCA)/ms (SCA)>1)and specific combining ability effects - non-additive (ms (GCA)/ms (SCA)<1). Genes with an additive effect participate in the genetic control of breeding-valuable traits, which is proven byms(GCA)/ms (SCA) ratios changing within1.10-28.01 range. It is advisable to involve CMS-lines A3 Feterita 14, A2 KVV 114 and A2 O-1237 to create high-yielding hybrids of grain sorghum; highly productive sorghum-sudangrasshybridss - lines L-106, L-143 and Anastasiya, Kinelskaya 100, Elegiya variety samples; with a high share of grain in the total biomass – Allegoriya, Krasnodarskaya 75 and Zonalskaya 6 variety samples. CMS lines are distinguished by high and average CA values both in crosses with samples of grain sorghum and Sudan grass: by weight of 1,000 grains - A2 O-1237; by seed yield and weight of 1,000 grains - A2 KVV 114.
Responses of onion growth and yield to different planting dates and land management practices
(Estonian University of Life Sciences, 2021) Salari, H.; Antil, R.S.; Saharawat, Y.S.
Local varieties of onion (Allium cepa L.) are believed to be well adopted to agroecological conditions of their respective growing region but their lower productivity is a concern to be addressed. The variety ‘Safid e Paisaye’ was selected for this investigation due to its long storability and higher market demand. The present study was carried out at Agriculture Research Farm of Kabul University to study the influence of land management practices and planting dates on growth and yield of onion. Different agronomic traits including number of leaves per plant, leaf length, leaf area per plant, leaf area index, normalized difference vegetation index (NDVI), maturity period, marketable yield and total yield were studied in these trials. The recorded data were statistically analysed with R software. The planting dates had significant influence on growth and yield of onions. At 90 days after sowing, the highest number of leaves per plant (7.18), leaf length (30.07 cm), leaf area per plant (277.43 cm2 ), leaf area index (0.93) and NDVI (0.29) were recorded for the first planting date (10th May). Similarly, the longest maturity period (176.44 days) and highest marketable yield (37.01 t ha-1 ) and total yield (40.08 t ha-1 ) were also observed under the first planting date. Land management practices did not have significant effect on growth and maturity period of onions. However, the marketable yield was influenced by tillage depth and land preparation. The deep tillage and flatbed recorded highest marketable yield of 38.58 t ha-1 and 26.9 t ha-1 , respectively. The results of the study indicate that, early planting was more appropriate to get vigorous and high yielding onions. The deep ploughed flatbeds were appropriate to get higher marketable yield of onions.
The productivity of spring barley when using cobalt nanoparticles and liquid-phase biological product
(2021) Seregina, T.; Chernikova, O.; Mazhaysky, Yu.; Ampleeva, L.
The purpose of this research is to study the effect of growth activators on the yield and quality of spring barley products. For the most complete disclosure of the potential yield of spring barley against the background of the application of minimal doses of organic fertilizers, cobalt nanoparticles were used, as well as a liquid-phase biological product (LPBP) in various combinations (NPСо, Compost, Compost + NPСо, Compost+ LPBP 1%, Compost+ LPBP 2%, Compost+ LPBP 1%+ NPСо, Compost+ LPBP 2%+ NPСо). The size of cobalt nanoparticles was 40–60 nm, the phase composition - Cо - 100%. A suspension of nanoparticles was obtained by dispersing with ultrasound in an aqueous solution in accordance with the requirements of the technical conditions. LPBP is a dark brown liquid with a specific odor, pH = 6.5–7.5, contains N, C, P, K, Ca, Mg, tryptophan, microorganisms. Cobalt nanopowder in solution contained 0.01 g per hectare seeding rate (20 mg L -1 ), LPBP concentration was 1% and 2%. Compost was used as an organic fertilizer; it consisted of 90% of cattle manure and 10% of poultry manure at a dose of 20 t ha-1 . The seeds were soaked 30 minutes before sowing in double distilled water, in a suspension of nanoparticles and LPBP in accordance with the experimental options. The analysis of the results of the research has shown that the studied preparations have a stimulating effect, contribute to an increase in resistance to suboptimal weather conditions, an increase in productivity and product quality. It was noted that the best indicators were obtained with joint pre-sowing treatment of seed material by cobalt nanoparticles with 1% solution of a liquid-phase biological product. Thus, there was an activation of growth processes, the yield increased by 35%, the content of crude protein - by 20.9%, digestible protein - by 10.9%, and crude fat - by 78.8%.
Community/shared solar power option: a pathway to sustainable rural electrification in Nigeria
(Estonian University of Life Sciences, 2021) Dunmade, I.
Nigerian governments at all levels have been making concerted effort to extend electricity supply to the rural areas. Among the several efforts by various governments are formulation of rural electrification policies, creation of agencies for the administration of rural electrification projects, installation of diesel power generators, and development of public-private partnership strategies in solving rural power supply problems. While significant progress has been made, several rural communities are yet to have access to electricity supply. Rugged terrain and limited financial resources are among the constraints to extension off-grid to the rural areas. However, electricity supply, being one of the drivers of economic development and social wellbeing, is a problem that has to be tackled head-on. The current climate change concern and many other environmental issues of our time necessitate finding a sustainable solution to the problem. Consequently the goal of this study was to examine the potentials of community solar power option as a sustainable rural electrification approach in Nigeria. Other goals included identifying potential hick-ups and solutions to lifecycle management of community solar. Moreover, the study was to determine the suitable configuration for efficient and sustainable community solar power management in Nigeria. The study methodology involved intensive literature survey, historical data collection and case studies on rural electrification in Nigeria as well as examples of community solar projects in Nigeria. Preliminary results revealed that community solar power would be a sustainable approach to rural electrification in Nigeria if a number of conditions are satisfied. Some of the conditions to be satisfied include devolving the management of a community solar system to a participative committee of stakeholders representatives, and incorporating community capacity building in the plan. Other conditions are government, corporate and municipalities’ collaboration in funding such projects from scratch till after one or two years of operation, and incorporation of monitoring and intervention strategies for continuous power supply and further improvement.
Some features of cultivating different Chamaenerion angustifolium (L.) Scop. forms in vitro
(Estonian University of Life Sciences, 2021) Egorova, D.A.; Molkanova, O.I.; Gorbunov, Yu.N.; Gulevich, A.A.; Baranova, E.N.
Chamaenerion angustifolium (L.) Scop. characterized by a wide range of economically useful properties. White-flowered form of Ch. angustifolium (L.) Scop. Is extremely rare in nature. At the same time, it is promising as a source of biologically active substances and as a highly decorative plant. The optimal way to reproduce this form is clonal micropropagation. Methods for obtaining Ch. angustifolium in vitro were developed, as well as the optimal selection timing of starting material for micropropagation was determined. In addition, the effect of a mineral composition of nutrient medium and plant growth regulators on the regeneration of microshoots was studied. The highest values of morphometric parameters were achieved on MS medium (Murashige & Skoog, 1962) supplemented with 0.5 mg L-1 BAP. The multiplication factor of the lilac–flowered form was 8.4 ± 0.2, of the white-flowered form - 9.2 ± 0.6. Comparative analysis of morphometric parameters during cultivation of Ch. angustifolium showed no significant difference between the lilac-flowered and white-flowered forms. The effect of antioxidants on the growth and development of regenerants has been shown. The most optimal nutrient medium for clonal micropropagation of the lilac-flowered form was MS medium (Murashige & Skoog, 1962) containing 0.5 mg L-1 of BAP, 50 mg L-1 of ascorbic acid and 50 mg L-1 of citric acids and for micropropagation of the white–flowered form it was the medium, containing 100 mg L-1 PVP.
Evaluation of morphological traits, genetic diversity and major resistance genes in barley subpopulations cultivated under organic and conventional farming systems
(2021) Šķipars, V.; Ruņģis, D.; Ločmele, I.; Seile, S.; Mežaka, I.; Legzdiņa, L.
Most crop varieties currently grown in organic conditions have been bred for conventional farming, and are not adapted to increased environmental variability under organic farming conditions and unpredictable environmental fluctuations due to climate change. This can be mitigated by the use of heterogeneous material, increasing genetic diversity and enabling adaptation to local conditions. The objective of this study was to determine the effects of several generations of cultivation in parallel under organic and conventional farming systems on the genetic diversity, morphological traits and frequency of major disease resistance genes as indicators of adaptation to the farming system in heterogeneous spring barley populations with differing levels of diversity. Populations in differing generations originating from crosses between two, three, 10 and 15 parental genotypes were cultivated in organic and conventional farming systems for three, four or 10 generations, thus forming subpopulations in each environment. These subpopulations were genotyped, and tested for morphological traits in both farming systems. A significant effect of cultivation environment on tillering capacity (p < 0.05) was found for all tested populations and in several cases for plant height, ear length and grain number per spike, indicating some adaptation trends. In the short term, genetic diversity parameters were not decreased in the later generation populations in comparison to the initial populations with the exception of observed heterozygosity, as expected for a self-pollinating species. No clear differences in genetic diversity parameters between populations cultivated under either organic or conventional condition for several generations were identified.
Digestate application with regard to greenhouse gases and physical soil properties
(2021) Šařec, P.; Korba, J.; Novák, V.; Křížová, K.
The article deals with the method of application of digestate with regard to the environment, soil properties and utilization of nutrients by plants. The aim is to monitor the dependence of the emission gas leakage and the dose of applied fertilizer. With the current expansion of biogas plants, a large amount of waste product, especially digestate, is being generated. This product is most often used as a liquid organic fertilizer because it contains substances important for plant growth. The disadvantage of this fertilizer is the release of greenhouse gases into the air. The digestate contains mainly ammonia, nitrogen in the residual organic matter and is a fertilizer with rapidly releasing nitrogen. The ammonium nitrogen contained in the digestate is easily subject to air losses. Therefore, a method of application for a certain crop is sought, where the smallest leaks of gases into the air occur. Different amounts of doses for the same route of administration are compared. To measure the amount of emission gases, a wind tunnel was placed on each variant of the application, taking air above the soil surface, which is discharged to the gas analyser. The monitored greenhouse gases are CH4, NH3 and CO2. Furthermore, physical properties of soil were monitored in order to verify the conditions of the experiment. One of the parameters measured was the soil bulk density of the soil by taking intact soil samples. The penetration resistance of the soil was also determined, which indicates the degree of compaction. The use of nutrients was assessed through the condition of the stand on each variant by monitoring vegetation indices using remote sensing of the earth.
Assessment of essential oil yield in three mint species in the climatic conditions of Central Russia
(2021) Shelepova, O.V.; Olekhnovich, L.S.; Konovalova, L.N.; Khusnetdinova, T.I.; Gulevich, A.A.; Baranova, E.N.
The aim of the study was to study the harvest time for the essential oil yield and its qualitative composition in three species of mint Mentha piperita L. (Peppermint), M. spicata L. (Spearmint) and M. arvensis var. piperascens Malinv. ex. Holmes (Sakhalinmint). In 2018, the research was performed with plants of second year of vegetation in the Laboratory of Plant Physiology and Immunity of the NV Tsitsin Main Botanical Garden of the RAS. As a result, it was found that the optimal harvest period for Sakhalinmint and Peppermint should be recommended in a phase of mass flowering: the yield of fresh raw materials was 509–479 g m-2 , air-dry raw materials - 110–107 g m-2 ; the content of essential oil in the aboveground part (a mixture of leaves and inflorescences) of plants - 3.24–4.01%; the proportion of the main component of essential oil (menthol) - 57.3–50.2%. In Spearmint, the optimum time for harvesting is the phase of budding. The content of the main component of essential oil (carvon) was maximum - 67.9%, and the yield of essential oil was 2.6%, while the yield was 381 g m-2 of fresh raw materials (81.9 g m-2 of air-dry raw materials) at harvesting in this ontogenesis stage. Analysis of the secretory apparatus parameters on a surface of some green tissues in three mint species showed that the maximum density of secretory glands on both sides of the leaf is characteristic of peppermint, which provides a higher yield of essential oil in this type of mint. The study allowed determining the optimal harvesting time for highly productive mint species when they are grown in the conditions of Central Russia. The raw materials of these mint species can be used for the production of essential oils and are of interest for pharmacology and the perfume and cosmetics industry.
Effect of replacement of coated barley grain with hulless barley in diet on growth, carcass and meat quality traits of fattening pigs
(2021) Degola, L.; Jansons, I.; Šterna, V.
A amount of experimental pigs were 40 crossbred pigs (Yorkshire × Landrace). The initial body weight of pigs were average 27.0 kg. The goal of research was to assess the effect of replacement of coated barley grain with hulless barley in diet on pig growth, carcass and pork quality indices. Experimental groups of pigs on the holding were conducted according to age and sex. For trial group of pigs, a compound feed with hulless barley (38.9–45.4%) was prepared, for the control with coated barley (39.3–43.3%). The feed recipes made according the pigs age. The other feed ingredients were not changed and were wheat, soybean meal and oil, premivit, and from 20 till 70 kg liveweight also fish meal. Diets were formulated with the same of metabolizable energy and crude protein content. During the study the live weight of pigs was monitored and the feed consumption was counted. At the end of the study all pigs slaughtered, determined carcasses traits and took samples of loin muscle for chemical analyses. The results showed that pig fattening indices (daily liveweight gain were in control pig group 0.686 ± 0.183 and trial 0.716 ± 0.174) did not differ significantly between groups (P > 0.05), although its were slightly lower in the control group pigs by 4.37%. Feed consumption for live weight gain in both groups ranged from 3.14 to 3.25 kg. Carcasses scores showed significant differences in lean meat and chops (P < 0.05). There were also differences in the backfat thickness. The thickness of backfat was 2.62 mm less in the control pig group, which indicates that when feeding coated barley to fattening pigs, the carcasses have a higher proportion of lean meat (62.1 ± 0.7%). Pigs were slaughtered reaching a live weight of 110 to 114 kg. The meat yield 71.7% and moisture level (70.2–75.2%), as well as protein (22.3–22.9%) indicators showed that fattening pigs are sold at the optimal age. In conclusion, results from this study suggest that feeding hulless barley to fattening pigs results in higher live weight gain. Carcass indicators showed a significantly higher proportion of lean meat and weight of chops when pigs eating coated barley. Chemical composition of pork in groups without significant differences.
The efficiency of nitrogen stabilizer at different soil temperatures on the physiological development and productivity of maize (Zea mays L.)
(Estonian University of Life Sciences, 2021) Rácz, D.; Gila, B.; Horváth, É.; Illés, Á.; Széles, A.
Nitrogen (N) stabilizer containing nitrapyrin inhibitor is responsible for slowing the activity of Nitrosomonas sp. bacteria down which oxidize ammonium to nitrite ions, thus, N-loss resulting from nitrate leaching can be reduced. Although prior studies have shown its effectiveness in the pre-sowing application in maize, considering that it disturbs the activity of Nitrosomonas bacteria which is the most intense between 25 °C and 30 °C, soil temperature may significantly influence the efficiency of nitrapyrin. Besides, nitrapyrin aims to enhance N-use efficiency in high N-demanding plants, such as maize, which demands N at the most during stalk elongation, which lays down the reason for its subsequent application. This study focuses on the efficiency of nitrapyrin at different soil temperatures and its impacts on the physiological development and productivity of maize. In a laboratory test, 10 °C, 15 °C, 20 °C, and 25 °C temperature soils were treated with nitrapyrin and change of nitrate content was monitored to observe the nitrification dynamic. Results show that as the soil temperature elevated, the inhibition efficiency increased. In a field experiment with maize, nitrapyrin was applied in 13 °C and 25 °C temperature soil. Results suggest the later treatment enhanced N-use efficiency, as, during the high N-demanding growth stage, more N-forms were available in the soil. This resulted in significantly higher relative chlorophyll concentration in the leaves and laboratory leaf analysis confirmed the prevention of N deficiency. Results of further measurements on parameters indicating biomass production such as root mass, stalk diameter, ear size, 1,000-kernel weight indicate that the nitrapyrin application should be timed later.
Delineation of catchment area for the lake Kisezers for environmental sustainability
(Estonian University of Life Sciences, 2021) Dumpis, J.; Lagzdins, A.; Sics, I.
The study aims to develop a methodology for the delineation of a catchment area. The methodology includes the processing and analysis of LiDAR data, on-field height measurement data, bathymetric data, hydrological data. High definition catchment area maps are successfully constructed. Catchment area influencing factors such as water mass movement and changes in land use are determined. Lake Kisezers was selected as the study site because the location of the lake, the availability of data, the feasibility studies, the economic potential of the catchment area determine the topicality and significance of this study. The lake catchment area covers multiple rivers, urban and rural territories, forests, high and low terrains. In the catchment area of Lake Kisezers many hydrologic monitoring stations with continuous data are situated. In the research area, we can study how those factors interact with the possibility to perform a catchment area delineation. The final result of this study is the catchment area for Lake Kisezers. The research results are high-definition and can be used to understand locations of floodplains, territories with malfunctioning drainage systems. The repetition of this study requires extensive knowledge of cartography, experience in working with terrain and bathymetry data, wide range of GIS knowledge. The research was performed using computer software such as QGIS and GRASS GIS. The application of the methodology used in this study can serve as an example for delineation and analysis of a catchment area for other lakes and rivers. Overall, the study is a success.
Dendrological collections of the Stavropol Botanical Garden: introduction and development prospects
(2021) Nezhentseva, T.V.; Koltsov, A.F.; Grishchenko, E.N.
Botanical gardens perform active introductory work, carry out educational and academic activities, preserve the gene pool of the red book species, and serve as a source of enrichment plant resources. The leading role in solving these problems is played by dendrological collections, on the basis of which botanical research is carried out. The main part of the woody collections is located in the Stavropol Botanical Garden (SBG) arboretum. Work on the construction of the SBG arboretum began in 1959. Initially, it was planned to collect various species, natural and cultural forms of woody and shrubby plants from the temperate, and partly northern and subtropical zones. In addition, four models of forest vegetation formations of the Stavropol Krai and Karachay-Cherkessia were created on the territory of the SBG. The article presents the main stages of the introduction work on the creation of dendrological collections, the methods used. Most of the collections were formed in a short time due to the preliminary selection and mobilization of planting material. The long period of introduction made it possible to judge the advantages and disadvantages of the chosen method of genus complexes. The modern composition of the collections is analyzed, the role of the introduction process in the conservation of biodiversity is noted. The species that are promising for use in the landscaping of the region are listed. In the future, work with dendrological collections implies the attraction of new species, the introduction of information technologies, continuation of study and monitoring of plants listed in the Red Books of the Stavropol Krai, Russia and the Red List of the International Union for Conservation of Nature.
The effect of cultivation technology on the plant development of organically grown garlic
(2021) Lepse, L.; Zeipiņa, S.; Missa, I.; Osvalde, A.
The new technological solutions for the hardneck garlic production were tested to prevent the influence of unfavourable soil and climatic conditions on the rooting, sprouting and wintering ability of hardneck garlic - factors that affect significantly the hardneck garlic production in Latvia. Field studies were carried out at the experimental field of the organic farm, located at the Koknese district, Latvia, during the seasons of 2018/2019 and 2019/2020, on sandy loam soil using hardneck garlic cultivar `Liubasha` and local clones. Two variants of garlic growing were compared - traditional planting in the autumn in the field as control, and planting in the trays as an innovative solution. Results indicated that low temperature treatment (below +7 °C) for the period of at least 50 days initiates cloves primordia development. The using of trays is effective technology to prevent unfavourable agroecological conditions on the field in the case if controlled conditions are available and technically feasible in the farm.
Sowing time effect on yield and quality of field beans in a changing meteorological situation in the Baltic region
(2021) Plūduma-Pauniņa, I.; Gaile, Z.; Bimšteine, G.
As field beans (Vicia faba L.) need a lot of moisture to germinate, growers believe that they should be sown as early as possible in the spring. Field trial was carried out at the LLU RSF “Pēterlauki”, from 2018 to 2020. Following factors were researched: A) sowing time (early, medium and late), B) variety (‘Laura’, ‘Boxer’, ‘Isabell’), C) sowing rate (30, 40, 50 germinable seeds m-2 ), D) fungicide application (without and with application of fungicide at the GS 61-65). Meteorological conditions during the study had the greatest impact on the results as they were contrasting. Adverse meteorological conditions for field bean growing were observed in 2018 and in spring and early summer of 2019. The best year for bean yield formation was 2020, when temperature and precipitation was moderate. The highest average three year been yield was obtained sowing beans at the medium sowing time, however, equivalent yield was obtained sowing beans also in early sowing time. Fungicide application increased average three year yield significantly (p = 0.007) and independently of the sowing time. Influence of variety and sowing rate on average three year yield was insignificant, and it was not proved that any variety or sowing rate could be more suitable in a specific sowing time. Average three-year values of crude protein content, thousand seed weight and volume weight were affected by sowing time significantly (p < 0.001). Trial year, variety and fungicide application also affected all quality parameters significantly (p < 0.05), but the effect of sowing rate was insignificant (p > 0.05).
DEM modelling of tillage tools in sand and verification of draft forces in the soil box
(Estonian University of Life Sciences, 2021) Kuře, J.; Linda, M.; Chotěborský, R.; Černilová, B.; Hromasová, M.
Soil resistance is still being important parameter during tillage. By reducing the soil resistance during processing, greater efficiency and cost reduction can be achieved. With the correct design of the shape of the tillage tools, reduction in the force required for tillage can be achieved. New tool designs must be tested in field conditions to determine the effect. Using DEM (Discrete element method) modelling, individual designs can be compared without the need for field tests. However, the accuracy of the model must first be verified on real tests. The paper deals with the creation of a mathematical model of sand, which is used for testing tillage tools in the soil box. The models are focused on tests of various shapes of wings on tillage tools. Draft forces are compared, and the correctness of the model is verified.
Development of stomatal conductance of maize under moderately hot, dry production conditions
(Estonian University of Life Sciences, 2021) Széles, A.; Horváth, É.; Rácz, D.; Dúzs, L.; Bojtor, Cs.; Huzsvai, L.
A field trial was conducted in Hungary, in a moderately warm, dry production area to determine the effect of single or split application of N-fertilizer on the stomatal conductance and grain yield of maize. The measurements were performed at on calcareous chernozem soil, in a strip field trial, under different weather conditions (2019 and 2020). In addition to the unfertilized control (A0) treatment, 60 (A60) and 120 kg N ha-1 (A120) applied as spring basal fertilizer were followed by two top-dressing treatments in V6 (A90) and V12 (A120) phenophases with doses of +30 and +30 kg N ha-1 , respectively. Stomatal conductance measurements were taken at V6, V12 and R1 phenological phases. It was found that stomatal conductance showed a decreasing trend with advancing phenological phases in both years, with 43.9% and 32.1% (P < 0.001; P < 0.01) decreases by the R1 phase, respectively. Application of higher doses of N fertilizer increased stomatal conductance, with the exception of the R1 phenological phase, which showed a decrease compared to the A0 treatment. The decrease in 2019 was caused by a reduction of soil moisture. Although there was sufficient water in the soil in 2020, due to the intermittent water shortages caused by but the large leaf area and rapid transpiration of the plants resulted in the stomata to close. The best fertilisation strategy was A60 and A120 kg ha-1 depending on the crop year. The study showed that the highest yield is obtained when the average stomatal conductance is around 250 mmol m-2 s -1 during the growing season.
Hybridspecific nutrient interactions and their role in maize yield quality
(Estonian University of Life Sciences, 2021) Bojtor, C.; Illés, Á.; Horváth, É.; Nagy, J.; Marton, L.C.
Different fertilization levels can be used according to the intensity of the plant production technology. The interactions among all the essential nutrients, the different ways of antagonisms and synergisms can weaken or strengthen the physiological processes of the plants, affecting significantly the efficiency of the production. Complex mineral profile of the vegetative (stalk, leaves) at V2, V4, V8, VT and R6 stages in 4 replications and generative (grain, cob -R6 stage only) plant parts of maize were determined in accredited laboratory with ICP-MS, ICP-OES microwave-assisted multielement analysis for metal components (P, K, mg, Ca, S, Zn, Fe, Cu, Mn, Ni, Mo) and Dumas method for nitrogen. Results showed that the effect of different nitrogen fertilization levels was significant on grain yield, protein, oil and moisture content. Significant differences were measured between the different maize genotypes in grain yield, protein and starch content. In the experiment all essential nutrient concentrations were measured, and the important nutrient ratios of macro- and micronutrients for the physiological development of maize were calculated. These nutrient stoichiometric ratios were evaluated according to their scale of influence in the yield formation. It can be concluded that different nitrogen fertilization levels affected significantly the essential nutrient ratios of the vegetative and generative plant parts of three maize hybrids in the growth period. Although different variables of nutrient stoichiometric ratios and yield parameters did not highly correlated, Pearson’s correlations suggest that K:Mg and K:Zn ratio of stalk would be related with grain yield (R = 0.32; 0.34; 0.39 and 0.35; 0.37; 0.30, respectively) marking them as important parameters for novel nutrient stoichiometry research. Analysing the optimal nutrient ratios related to the yield quality and their interaction with the fertilization practices can give certain recommendations to the farmers to implement hybrid- and site-specific nutrient management strategies, reducing the environmental impact of the over-fertilization.
Micromorphological features of the leaf epidermis of the evening primrose cultivars of the VILAR biocollection
(2021) Savchenko, O.M.; Totskaya, S.A.; Gryaznov, M.Yu.
Novelty of the work. For the first time, a comparative study of the epidermis of the leaf plates of four cultivars of Oenothera biennis L. was carried out. The aim of the work. Study and comparison of morpho-anatomical signs of the epidermis of the leaf plate of the cultivars of evening primrose to reveal their potential ecological plasticity. Materials and methods. There were used leaves of plants of the second year of life in the phase of mass flowering. Micromorphological study of the epidermis of leaf plates included: determination of the shape of the main cells of the epidermis, the size and number of stomata per 1 mm2 , the type of stomatal apparatus, the presence and parameters of trichomes. The number of trichomes was calculated per 1 mm2 . Results. In the Genoteros cultivar, the stomata were smaller; their number on the lower epidermis was the lowest. Two types of trichomes were classified. At cultivar Genoteros unicellular covering trichomes were mainly located in the upper epidermis of the leaf. No covering trichomes were found in the Svetlyachok cultivar. The Tverskoj cultivar differs in the length of the hairs: from 774 to 790 microns. Papillary single-celled trichomes on the leaves of the studied cultivar of evening primrose are concentrated on both sides of the epidermis, mostly in the middle part of the leaf, less often - in the mesophyll space. Conclusion. Based on the obtained data, the authors established the potential ecological plasticity of the studied varieties of evening primrose for the subsequent study of the influence of stress factors on the described cultivars. The results obtained may be important taxonomic for the correct identification of problematic Onagraceae taxa and in further breeding work.

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Sirvi 2021, Vol. 19, No. 4 Kuupäev järgi

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