Sirvi Autor "Jansone, I." järgi
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Kirje Carbon and nitrogen accumulation by agricultural crop residue under three cropping systems(Estonian University of Life Sciences, 2025) Rancāne, S.; Lazdiņš, A.; Petaja, G.; Purviņa, D.; Zute, S.; Jansone, I.; Damškalne, M.; Putniece, G.Agricultural crops produce different biomass during their growth, including varying amounts of residue which accumulate a significant amount of carbon (C) and nitrogen (N). Assimilation capacity depends largely on species, variety and growing condition. Carbon accumulation in soil contributes to both - the agricultural production and maintenance of environmental quality reducing atmospheric C and greenhouse gas emissions. In this study, the amount of plant residue left on the field by above-ground and below-ground residue and the amount of C and N accumulated in them in three different cropping systems: organic (Bio); integrated with a low input of N fertiliser (Int-low-N) and; integrated with a high input of N fertiliser (Int-high-N) were evaluated. The most commonly grown cereal crops in Latvia were tested: winter wheat (WW); summer wheat (SW); winter rye (WR); winter triticale (WT); summer barley (SB); summer oat (SO); and buckwheat (BW) as pseudo-cereal crop. The highest biomass of dry matter of total harvest residue in all cropping systems was recorded in WR: 853.3 ± 40.76 g m-2; 1,482.0 ± 105.06 g m-2; 1,628.3 ± 115.49 g m-2 - in Bio; Int-low-N; Int-high-N cropping systems, respectively. The highest amount of carbon (g C m-2) using organic cropping system was accumulated by residue of: WR (268.6 ± 28.68), BW (239.4 ± 10.50) and WW (234.5 ± 27.41). The highest amount of carbon (g C m-2) using integrated cropping system was accumulated by residue of: WR - 473.8 ± 64.9; 496.6 ± 62.54 and WT - 458.2 ± 32.57; 521.1 ± 46.26 in Int-low-N and Int-high-N, respectively. Higher proportion of root biomass cereals formed using organic cropping system.Kirje Carbon and nitrogen uptake in above- and below-ground biomass of cereal crops in the integrated farming system(Estonian University of Life Sciences, 2023) Rancane, S.; Lazdins, A.; Zusevica, A.; Zute, S.; Jansone, I.; Damskalne, M.; Zarina, L.; Korolova, J.; Maliarenko, O.A significant reduction in greenhouse gas (GHG) emissions, as well as technologies that ensure removal of CO2 from the atmosphere, are necessary to achieve the set goals for the transition to carbon neutrality. During the crop growth cycle, a significant amount of biomass is produced, and carbon (C) and nitrogen (N) are captured both by the harvested crop removed from the field and by residues left on the field. The trials were conducted to find out patterns between crop and residues while trying to figure out the amount of captured C and N. In this study data of the most widely grown cereal crops in Latvia are summarized. The data are representative, obtained in different agroclimatic conditions, they vary both by species and variety, by year and fertilizers applied. The mean amount of biomass from cereal crops left on the field was 1,070.9 g m-2 DM, besides, 906.7 g m-2 of that was made up of above-ground (AG) residues and 164.2 g m-2 of below-ground (BG) residues. On average, 471.8 g m-2 C and 14.3 g m-2 N were captured, including: 411.2 g m-2 C and 12.9 g m-2 N by AG residues; 60.7 g m-2 C and 1.4 g m-2 N by BG residues. Regularities between grain yield and residues were found, however, they were not very strong. The dataset should be enlarged to reduce uncertainty. As the data calculated from crop have a greater uncertainty, the GHG inventory should be calculated according to the average AG and BG biomass, which provide more accurate data.Kirje Evaluation of various legume species and varieties grown in Latvia as a raw material of plant-based protein products(2020) Sterna, V.; Zute, S.; Jansone, I.; Ence, E.; Strausa, E.Nutrition value of legumes has been traditionally attributed to its high protein content. Protein content of legumes is variable dependent on different species and varieties, and highly affected by environmental factors. Usually protein quality is characterized by its owns amino acid profile in nutritional point of view. Therefore, the present study was conducted to determine the protein contents and amino acid profiles of pea (Pisum sativum L), faba beans (Vicia faba L) and soya (Glycine max L) grown in Latvia and evaluate their potential for food production. Overall results of a five-year analysis (2013–2017) showed that the protein content of peas, faba beans and soybean ranged from 20.0 to 26.1%, 26.6 to 30.5% and 35.9 to 40.9%, respectively. The corresponding values of total crude fat ranged from 0.8 to 1.2%, 0.7–1.3% and 16.6 to 19.3%, respectively. Results of study showed that the protein content of peas, faba beans and soybean was not differed by growing system (p < 0.05). The percentage of essential amino acids for pea, faba bean and soya were 34 to 38%, 57 to 59% and 62 to 64% respectively. The composition of pea flakes was preserved protein content of raw material. The pea flakes has high content of lysine of 10.1 g kg-1 , phenylalanine+thyrosine of 11.6 g kg-1 and the sum of essential amino acids of 66.4 g kg-1 . In nutritional point of view, pea flakes could be product with high-quality proten composition.Kirje Exploring the economic viability and agronomic effects of green manure mixtures on winter wheat yields in organic farming in Latvia: a multi-location study(Estonian University of Life Sciences, 2025) Morozova, I.; Jansone, I.; Cerina, S.This study explores the adaptation of green manure practices to Latvia’s climatic and soil conditions to enhance soil productivity and economic returns in organic farming systems. The study aims to identify the most suitable green manure mixture by evaluating economic factors, dry matter yield, nutrient amount, and its impact on winter wheat yields in organic fields across different locations in Latvia, considering variations in meteorological conditions. Field trials compared three mixtures: oats-mustard-oilseed rape–buckwheat (non-legume), oats-buckwheat-peas (legumes < 50%), and oats-lupin-vetch (legumes > 50%) against a control (black fallow). Data were collected on dry matter production, nutrient accumulation (N, P, K amount), winter wheat yields, and economic performance. The results revealed a significant variation in dry matter yield depending on year and location. Mixture with non-legumes at the farms ‘Gaikeni’ and ‘Geidas’, as well as mixture with legumes below 50% at ‘Gaikeni’, Ltd. ‘Mazbungas’, and ‘IRGK serviss’, produced significantly higher dry matter yields (P < 0.05). Despite lower biomass yield in certain years, mixture with legumes above 50%, through the follow-up effect, significantly increased winter wheat yields under optimal conditions at Ltd. ‘Mazbungas’ and farm ‘Gaikeni’ being higher by 96.05% and 93.59%, respectively, compared to the control. Economic analysis revealed significant gross margin advantages for green manure cultivation, demonstrating its financial viability. This study underscores the potential of green manure practices in enhancing the sustainability of organic farming, improving yields, and increasing profitability, while highlighting the importance of selecting region-specific mixtures to account for climatic variability.