Poiša, Liena

2011-03-05, Poiša, Liena, Aleksandrs Adamovics

Hemp (Cannabis sativa L.) as an Environmentally Friendly Energyplant. Hemp is suitable as a renewable energy resource. The aim of this study was to clarify local hemp's (Cannabis sativa L.) possibilities for energy use. Arsenic (As), cadmium (Cd), lead (Pb) and titanium (Ti) presence in hemp was determined using an inductively coupled plasma optical emission spectrometer Optima 2100 DV. If there were increased N fertilizer rates, there were increased hemp ‘Pūriņi’ seeds and shive yield increases, but the oil content was reduced. Arsenic content was higher in the shives than in the stems with fibre. The ash content depends on non-organic substances which the plants absorb during the vegetation season. The lignin content depends on several factors: plant parts, and the N fertilizer rate. The unexplored factors have a great effect on the ash and lignin content. Hemp is suitable for cultivation and for bio-energy production in the agro-climatic conditions in Latvia.

2013, Rasma Platače, Natalia Tsurkan, Poiša, Liena, Aleksandrs Adamovičs, Kristīne Ivanova

2023, Aleksandrs Adamovičs, Poiša, Liena, Lydiia Antypova

Field trials with the two potato variety were carried out in sod stagnogley soil. Soil agrochemical parameters: pHKCl 6.7 organic matter (OV) content in soil 2.3%, phosphorus (P2O5) content - 149 mg kg-1 and potassium (K2O) content - 200 mg kg-1 in soil. Potato plantations were created using different variants of fertilizer mix with pig (from SIA “Latvi Dan Agro”) and cattle (from SIA “Ziedi JP”) manure digestate and wood ash (from SIA“Gren Jelgava”) in different ratio (digestate :wood ash ratio used: 4:1and 3:1). The rates of innovative mixed fertilizer for pig and cattle manure digestates for potatoes were 15 and 30 t ha-1. Both norms for digestate manure from pure pigs and cattle were used as control options. The potato production norm was 3.0 t ha-1. The placement of the variants in the trial was randomized, in triplicate. In the study, the two types of fertilizer had different effects on potato tuber yield. Using mixtures of pig manure digestate and wood ash in different ratios, the average yield was 34.2 t ha-1, but using mixtures of cattle manure digestate and wood ash, the average yield was 27.8 t ha-1. In the studied variants, its content in potato dry matter varied in the range of 9.15-11.42%. The amount of dry matter affects the culinary properties of the tubers. The application of fertilizer mixtures increased the dry matter content by an average of 1.7–2.7%. Fertilizer variants with higher tuber yield or higher starch content provided the highest starch yield.  In general, the use of mixtures of wood ash and biogas digestate to fertilize crops and improve soil fertility can be an efficient way to process both products and can be an environmentally friendly alternative to fertilizers. The objective of the research was to study the influence of digestate and wood ash mixtures fertilizer rates on potato productivity and quality.

2010, Poiša, Liena, Aleksandrs Adamovičs, Veneranda Stramkale, Ļubova Komlajeva

The renewable energy acquisition reduces dependence on fossil energy, which has a beneficial impact not only on agriculture but also on the country's economic development, since it has reduced the amount of bad emissions and the quantity of imports. This study is to determine the carbon content, ash content and yield influencing factors of linseed in order to clarify the possible use of alternative energy. The linseed is suitable for energy production from biomass, because it is derived from different products, which are used for solid fuel and bio diesel production.

2011-03-05, Rasma Platace, Aleksandrs Adamovics, Poiša, Liena

One of the major factors in achieving more biofuel is the amount of crop yield, but that is not synonymous with the yield quality. Plants are contaminated by heavy metals not only through the soil, but also from atmospheric pollution. The aim of this research was to establish the amount of heavy metals in the dry matter of reed canarygrass (Phalaris arundinacea L.). The Marathon variety of reed canarygrass was studied with two sowing periods and four Nfertilizer rate applications. The concentration level of arsenic (As), cadmium (Cd), lead (Pb) and titanium (Ti) in the samples of reed canarygrass were analysed with the coupled plasma optical emission spectrometer Perkin Elmer 2100 DV. The samples of reed canarygrass taken in April had a greater concentration of As, Cd, Pb, which means that the plants absorb the heavy metals also from the snow covering. The first year yield of reed canarygrass established a fundamental negative correlation between the amount of As, Cd, Pb and the ash content. The samples taken in April have a greater heavy metal contamination, than the samples taken in October. The sowing period fundamentally affected the concentration of lead in reed canarygrass samples, but the level of N-fertilizer rate application affected the amount of cadmium and arsenic.

2023, Aleksandrs Adamovičs, Poiša, Liena

Garlic (Allium sativum L.) is a widespread crop in vegetable production. The popularity of garlic is due to its bactericidal and antioxidant properties. Digestate and wood ash are the by-products of cogeneration plants. The digestate is rich in nutrients, can provide a large part of the nutrients needed by the plant during the growing season, as well as improves the soil structure. Wood ash contains small amounts of phosphorus and potassium and is strongly alkaline (pH 8–12) due to the oxides in its composition, mostly calcium carbonate. The purpose of the study was to determine the effect of fertilizer rates of the digestate and wood ash mixtures on winter garlic productivity and harvest quality. Field trials with the winter garlic variety 'Lubaša' were established in sod clay, loamy soil. In the garlic plantation, different variants of fertilizer mixtures were used – they contained pig or cattle manure or plant residue digestate, and wood ash. The ratio of digestate and wood ash in the mixtures was 3:1; fertilizer rates for winter garlic were 15 and 30 t ha-1. In the study, the different types of fertilizers showed different effects on the yield and quality of winter garlic.

2015, Poiša, Liena, Veneranda Stramkale, Aleksandrs Adamovičs

Bioethanol production is one of cereal’s using ways. COM 2003/30/EC: Directive on the promotion of the use of biofuels or other renewable fuels for transport orders that proportion of biofuels in 2010 must be -5.75% but in 2020 – 10%. The object of research is to study the influence of winter crops cultivation’s technology on quality of grain and suitability for bioethanol production. Field research was organized in the Agricultural Science Centre of Latgale from 2005 to 2008. There were researched 5 fertilizer rates and the influence of varieties on the grain yield and starch in the experiment for 3 years. Starch content, yield and the result of bioethanol have changed depended on species of cereals, varieties, growing year and fertilizer rate. It is recommended to use good quality grains with high starch content and low protein content for bioethanol production.

2017, Skaidrīte Būmane, Poiša, Liena, Aleksandrs Adamovičs, Rasma Platače, Edgars Čubars

For solid fuels ash melting temperature is recommended to be higher than 1000°C, so that it can be used in automated furnaces; therefore-promising energy crops are investigated as renewable energy source. This paper presents the results of tests on melting temperature of different energy crop ashes.The field trial was carried out in the study farm of the Latvia University of Agriculture "Pēterlauki" (56°53'N, 23°71'E) in the sod calcareous soils characterized by pH KCl 6.7, P 52 mg kg-1, K 128 mg kg-1, organic matter content from 21 to 25 g kg-1 in the soil. Energy crops analysed: reed canary grass (Phalaris arundinacea L.), birch (Betula pendula Roth.), osier (Salix spp.), grey alder (Alnus incana (L.) Moench), poplar (Populus tremula L.), hybrid aspen (Populus tremuloides x Populus tremula). Results indicate that the ash melting temperature (D, St, Ht, Ft) for the wood energy crops were higher than for the studied grass energy crops and their mixture. Ash melting temperature in all phases over 1200°C was observed for such poplar and hybrid aspen mixture proportions: 3 parts of wood and 1 part of reed canary grass, or 1 part of wood and 1 part of reed canary grass.

2011, Poiša, Liena, A. Adamovičs, L. Antipova, G. Šiaudinis, D. Karčauskienė, R. Platače, A. Žukauskaitė, S. Malakauskaitė, Teirumnieka, Ērika

The paper presents the data of gaseous and alkali elements in above-ground biomass of energy crops. The investigations objects were Phalaris arundinacea L., Populus nigra, Artemisia vulgaris, Sylphium perfoliatum, Sida hermaphrodita, Dactylis glomerata, Salix viminalis, Medicago sativia L. The aim of the research: to evaluate the amount of chemical elements in energy crops. Evaluating the energy crops it can be seen, that the most alkaline metals are contained in Sida hermaphrodita, and the least in Sylphium perfoliatum L.

2022, Poiša, Liena, LIDIA ANTIPOVA

The topicality of the topic is due to the need to develop the production of energy crops, in particular hemp, given the limited amount of available minerals for the needs of heat supply. Hemp is suitable for biofuel production as a profitable crop with a wide range of uses. For the purpose of the study, the authors assessed the influence of agrotechnical factors on the productivity of sowing and quality indicators of hemp seeds for the production of solid fuel in Latvia. The Polish hemp variety “Bialobrzeskie” and the Latvian hemp variety “Pūriņi” were evaluated for application of 3 doses of nitrogen fertilizers. Analyzes are used, which are classified as systemic, statistical and comparative. Research methods are applied: generally accepted in crop production, field and laboratory – to clarify the interaction of the object of research with agrotechnical and natural abiotic factors; calculated and weighted – to determine the productivity of crops; calculation and comparison; mathematical and statistical (dispersion) – for assessing the probability of research results. It was determined that for fibrous hemp, the dry matter yield of the stem ranges from 6.5 to 11.0 t/ha, and the seed yield is 0.7-1.4 t/ha. The productivity of hemp significantly depends on agrotechnical factors, in particular, on the variety and application of fertilizers, because these component technologies significantly affect the yield and quality indicators of seeds for the production of solid biofuel. The hemp variety “Pūriņi” is less productive than the hemp variety “Bialobrzeskie”, even with the use of N100 nitrogen fertilizer dose. The dose of nitrogen fertilizers affects such energy parameters as ash content and the highest calorific value. The research revealed a significant (Р<0.05) influence of the trunk fraction on productivity, the highest calorific value and ash content. The scientific novelty is that the impact of the variety and doses of nitrogen fertilizers on productivity, including the energy properties of hemp, has been evaluated, and the practical value is in the improvement of the technology of growing hemp by correctly selecting the variety and optimizing the dose of nitrogen fertilizers to create high-quality products for heating and use of waste-free technologies