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Garlic (Allium sativum L.) is a widespread crop in vegetable production. The popularity of garlic is due to its bactericidal and antioxidant properties. Field trials with the winter garlic variety 'Lubaša' were established during two vegetation seasons of 2020/2021 and 2021/2022 in Terric Anthrosol (56°66' N, 23°75' E). Agrochemical indicators of the soil were the following: pHKCl 6.7, organic matter content – 3.8%, phosphorus (P2O5) content – 199 mg kg-1, and potassium (K2O) content – 97 mg kg-1 soil. Different variants of fertilizer mixtures with the digestates of pig manure (from LLC "Latvi Dan Agro"), cattle manure (from JSC "Ziedi JP"), and plant residue (from the farm "Līgo"), as well as wood ash (from LLC "Gren Jelgava") were used in the garlic plantations. Using these components, mixtures of relevant variants were prepared in the Biogas Scientific Laboratory of Latvia University of Life Sciences and Technologies. The ratio of digestate and wood ash in the mixtures was 3:1, and fertilizer rates for winter garlic were 15 and 30 t ha-1 . The pre-plant was black fallow; the planting rate of winter garlic cloves was 1.6 t ha-1 . Fertilizer was incorporated into the soil and garlic was planted by hand. The plot area in replicates was 2 m² for recording the harvest. During the vegetation period, the development dynamics of winter garlic was registered, the harvest was recorded, and the quality of garlic bulbs was evaluated: the content of dry matter, crude protein, sulfur, phosphorus, potassium, and reducing sugars in dry garlic bulbs. Depending on the type of fertilizer, the yield varied between 8.92 and 9.15 t ha-1 . The use of different types of digestates, including mixtures with wood ash, ensured a significant (p<0.05) increase in the yield of winter garlic bulbs which on average was by 0.71–0.94 t ha-1 larger compared to the control variant. Fertilizer mixture norms did not significantly affect the changes in crude protein content in garlic, thus it fluctuated between 6.1% and 7.8% in the total dry matter of the studied variants. The sugar content in the experimental samples of garlic was in the range of 0.53-0.70%. Depending on the fertilizer rate and type applied, the sulfur content in total dry matter was 0.28–0.70%. [ABSTRACT FROM AUTHOR]

Field trials were conducted in the spring of 2021 and 2022 at “Peterlauki” Study and Research Farm (56°53' N, 23°71' E) of the Latvia University of Life Sciences and Technologies. Soil characteristics: sod calcareous soil, granulometric composition which means heavy dusty sand clay. Soil agrochemical parameters: pH KCL 6.7 organic matter content was 26 g kg-1, phosphorus content was 60 mg kg-1 P2O5, and potassium content was 144 mg kg -1 K2O. Spring barley sowings were developed using different variants of fertilizer mix with cattle (from SIA “Ziedi JP”) manure digestate (GD) and wood ash (P) (from “Green Jelgava”, Ltd.) in different ratios. The norms of innovative mixed fertilizer for cattle manure digestate and wood ash were 5,10, 20 t ha-1 . Unfertilized winter oilseed rape fields were used as control. Variants in the two-factor trial were randomized in triplicate. In the experiment, the influence of the researched factors on the structural elements forming the spring barley crop, grain yield, starch and protein content in spring barley grains, grain volumetric weight (kg hL-1 ) and the mass of 1000 grains were determined. It was established that the average spring barley grain yield in the control variant was 2.61t ha-1, which is significantly (p<0.05) lower than in the variants using fertilizers of digestate and wood ash mixtures -3.18 ha-1 . [ABSTRACT FROM AUTHOR]

The use of biological by-products for soil improvement corresponds to circular economy and also contributes to longer and slower supply of nutrients to the soil necessary for tree plantations in natural ecosystems. The authors tested the effects of different proportions of wood ash and biogas digestate mixtures on growth parameters of Scots pine Pinus sylvestris, as well as understory vegetation. The results show that more than two growing seasons are rto assess the effect of soil amendment on slow-growing woody plants. The negative effects of fertilization on understory vegetation were not observed. [ABSTRACT FROM AUTHOR]

In order to promote a balanced development of agriculture and forestry, the scientists of the Latvia University of Life Sciences and Technologies (LBTU) within the framework of the cooperation project of nine partners researhed to use the by-products of biogas production plants and cogeneration plants for the purpose of soil liming and fertilization, which, as a result, created a new innovative product from the mixtures of the by-products. Wood ash was mixed with digestate in certain proportions based on the laboratory studies on the chemical composition of the raw materials. The effectiveness of the composition of the mixtures was first tested on soils of different acidity in a greenhouse, using the fast-growing plant species lettuce and cucumber. The preparation of the best mixtures evaluated in greenhouses under production conditions was carried out at the companies "Ziedi JP, Ltd" and "Pampāļi, Ltd". The production scheme of soil liming and fertilization was developed and approved at both companies. The set of machines and aggregates required for the preparation and spreading of the new type of fertilizer on the field was made. The digestate, after complete development in bioreactors, was fed to the mechanical screw press separator, where it was divided into solid (dry matter< 25 %) and liquid (dry matter >3%) fractions. The digestate of solid fractions was mixed with wood ash in portions in a screw-type mixer equipped with electronic scales. The ingredients were poured in parts so that the mixer could mix a uniform mass. The mixing process for each batch took 10-15 minutes to obtain a perfectly uniform and consistent mixture. [ABSTRACT FROM AUTHOR]

It is important to provide winter oilseed rape (Brassica napus L.) with the required nutrients for successful growth. Biogas plants and solid fuel boilers widely used for energy and heat production create wood ash and digestates as by-products. In agriculture, both wood ash and biomass digestate are used separately as liming and fertilizer materials, while mixtures of digestate and ash can provide a high-quality fertilizer that increase the productivity and yield quality of various agricultural crops including winter oilseed rape. Field trials were conducted in the autumn of 2020 at the Study and Research Farm “Peterlauki” (56°53' N, 23°71' E) of the Latvia University of Life Sciences and Technologies. Soil has the following characteristics: sod calcareous soil, granulometric composition – heavy dusty sand clay. Soil agrochemical parameters: pH KCL 6.7 (LVS ISO 10390: 2006); organic matter content – 26 g kg-1(by Tyurin method, LV ST ZM 80-91), phosphorus content – 60 mg kg-1P2O5, and potassium content – 144 mg kg -1K2O (according to Egner-Rhym method, LV ST ZM 82- 97). Winter oilseed rape sowings were developed using different variants of fertilizer mix with cattle (from SIA “Ziedi JP”) manure digestate (GD) and wood ash (P) (from SIA “Green Jelgava”) in different ratios [digestate used : wood ash ratio - (B1 - GD; B2 - GD + P 1:1; B 3 - GD + P 2:1; B 4 - GD + P 3:1; B 5 - GD + P 3:1 + N16P40K60 kg ha-1; B 6 - GD + P 3: 1 + N 68.8 kg ha-1; B 7 - GD + P 4: 1)]. The norms of innovative mixed fertilizer for cattle manure digestate and wood ash were the following: A1 - 5 t ha-1; A2 - 10 t ha-1; A3 - 20 t ha-1. Winter oilseed rape fields without fertilizers and bovine manure digestate (GD) fertilizer rates were used as control options. Variants in the two-factor trial were randomized in triplicate. Studies have shown that good winter rapeseed yields can be obtained without the use of mineral fertilizers using wood ash and digestate mixtures. The highest winter rapeseed yield in the observed time period was obtained from variants where fertilizer rates of 10 t ha-1were used. Winter oilseed rape seeds had a higher oil content in the variants in which 5 t ha-1fertilizer mixture was utilized. The bulk density of winter rape seeds in the studied variants this year wawas only slightly higher than 67.0 kg hL-1. The aim of the study was to determine the effect of different digestate and wood ash mixtures on the productivity and yield quality of winter oilseed rape. [ABSTRACT FROM AUTHOR]

Field trials with the potato variety ‘Rigonda’ were carried out in sod stagnogley soil (56 ° 66 'N, 23 ° 75' E). Soil agrochemical parameters: pHKCl 6.7 organic matter (OV) content in soil 2.3%, phosphorus (P2O5) content - 149 mg kg-1and potassium (K2O) content - 200 mg kg-1in 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”) of different ratio (digestate: wood ash ratio used: 4:1 and 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 24.92 t ha-1, but using mixtures of bovine manure digestate and wood ash, the average yield was 22.78 t ha-1. The dry matter and crude protein content are the most ecologically sustainable indicator in potato tubers. The crude protein content of tubers determines the nutritional value of potatoes. In the studied variants, its content in potato dry matter varied in the range of 8.28–10.94%. 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 1.4–2.0%, reaching an average of 21%. Starch is the main ingredient in potatoes. Fertilizer variants with higher tuber yield or higher starch content provided the highest starch yield. In our studies, the average starch content in the dry matter was 73.3% and 15.3% in the natural product, but the average starch yield was 3.55 t ha-1. 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. [ABSTRACT FROM AUTHOR]

Direct sowing or no-till sowing has become a widespread tillage in many countries around the world as it is very beneficial from an agronomic, ecological and economic point of view. The aim of the study was to evaluate the effect of direct sowing and fertilization norms on the productivity of summer rape sowings. Field trials with summer oilseed rape 'Heros' were carried out on sod stagnogley soil (55 ° 88 'N, 26 ° 53' E). Soil agrochemical parameters: pHKCl 5.8, organic matter content in soil – 3.8 %, phosphorus content - 122 mg kg-1 P2O5 and potassium content - 181 mg kg-1 K2O. Summer rape sowings were conducted by using the following variants: seed sowing norms: 7 and 10 kg ha-1; in the norms of nitrogen fertilizers: N0, N100 and N180; herbicide Fuego top rates: 0 and 2 L ha-1. The placement of the variants in the three-factor trial was randomized in four replicates. Precrop was winter wheat. Weed inventory was carried out by weight and by species during the vegetation period of summer oilseed rape. The sowing density, yield structure and yield were recorded for each experimental variant in all replicates at the end of the vegetation, and the yield quality was determined, i.e., 1000 seed mass, seed bulk density, oil content and oil extraction per hectare. In the studied variants, the number of seeds in pods changed on average within 20-25 number limit. The bulk density of the seeds was 62 kg hL-1 with an average weight of 3.2 grams per 1000 seeds. The oil content of the seed in the control variants averaged to 46.2%, regardless of the sowing rate, but the nitrogen fertilizer rates had a negative effect on the oil content and reduced it by an average of 2-3%. The seed yield in the control variants averaged to 0.84 t ha-1. Nitrogen fertilizer norms promoted higher seed yield and at N100 kg ha-1 it was 1.11 t ha-1, but at N180 kg ha-1 - 1.27 t ha-1 with average oil yield of 0.39, 0.51 and 0.59 t ha-1, respectively. [ABSTRACT FROM AUTHOR]

In a grassland experiment of the Research and Study farm "Peterlauki" (56°53'N, 23°71'E) of the Latvia University of Agriculture (LLU) from 2012 to 2016, it was found that fertilizer is an essential factor in increasing the dry matter yield of herbaceous plants. Phosphorus and potassium fertilizers (P80K120) increased the dry matter yield of five grass species (reed canary grass, festulolium, timothy, meadow fescue, and tall fescue) by 21% on average (from 9% for tall fescue to 31 % for timothy and 32 % for meadow fescue). When nitrogen was used ≥90 kg ha-1 N for all grass species, nitrogen content in biomass increased considerably. Significant differences in phosphorus content in fertilizer variants were not observed. Potassium content in the biomass of herbaceous plants increased under the influence of both fertilizers - PK and NPK. In the variants with no fertilizer application, 49.7 kg ha-1 of N, 27.8 kg ha-1 of P2O5 and 117.2 kg ha-1 of K2O were removed in plant dry matter from the soil. When herbaceous plants were fertilized with phosphorus and potassium (P80K120), the removal of plant nutrients in dry matter increased by 17% of nitrogen, 16 % of phosphorus, and 23% of potassium. [ABSTRACT FROM AUTHOR]

Agriculture (including hemp production and processing) is one of the industries subject to risks due to changing weather conditions, diseases, pests and volatile market prices on inputs and products produced. However, the use of risk assessment methodologies in hemp production and in agriculture as a whole are not widespread. This article aims to reflect the preliminary results of the risk evaluation in hemp production and processing. The following tasks were set to reach this aim: to analyze the risk evaluation methodology and risk calculation methodology; to determine and systematize risks in hemp production and to carry out a preliminary evaluation for risks in hemp production using semi-quantitative evaluation. For the evaluation purposes the hemp production is divided in five stages - preparation of soil and sowing of hemp; growing of hemp; hemp harvesting; hemp processing; and selling of the produced output. The evaluation of risks was done within a system of 18 risks, divided in six main groups - agro-meteorological; technological and production; personnel; environment; legislative; economic, and market risks. The results indicate that the highest risk level in the entire hemp production and processing process was specific to the group of personnel risks, whereas the lowest - to the group of environmental risks. [ABSTRACT FROM AUTHOR]

The sector of hemp growing and processing is subjected to significant changes through the past decades, historically hemp growing was widespread and in Latvia hemp was broadly used in everyday life -- in the local cuisine, for feeding animals and also as a building and textile material. It had lost its popularity but following the global tendencies in agriculture, growing and processing of hemp (cannabis sativa L.) is slowly regaining its positions mainly due to the versatile possibilities of using hemp. Though the total number of hemp growers is significantly smaller nowadays as it has been historically, the use of hemp is expanding and during recent years several enterprises have introduced new products that includes using hemp in food production, production of ecological construction materials, paper, production of textiles, biodegradable plastics and as mentioned, renewable energy production. Agriculture, including hemp production and processing, is one of the industries subject to risks due to changing weather conditions, diseases and pests and volatile market prices on inputs and products produced. This article aims to reflect the results of the risk evaluation in hemp production and processing, for the evaluation purposes the hemp production is divided in five stages -- preparation of soil and sowing of hemp; growing of hemp; hemp harvesting; hemp processing; and realisation of the produced output. The evaluation of risks was made within a system of 18 risks, divided in 6 main groups -- agrometeorological; technological and production; personnel; environment; legislative; economical and market risks. The results reviles, that the highest risk level in the entire hemp production and processing process was specific to the group of personnel risks, whereas the lowest -- to the group of environmental risks. However, some risks were assessed as the highest for the group of technological and production risks, for instance, the unavailability of machinery during hemp harvesting and processing. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate an impact of nitrogen fertilizer rates on industrial hemp's (Cannabis sativa L.) growth and development in Latvia. The trial was carried out during 2012 on the Research and Study farm Peterlauki of the Latvia University of Agriculture in the sod calcareous soil. There were three industrial hemp cultivars 'Futura 75', 'Tygra' and 'Felina 32' tested under different fertilizer rates: N0P0K0 -- control, N0P80K112 -- background fertilizer (in text marked as F), F+N30, F+N60, F+N90, F+N120, F+N150, F+N180 kg ha-1. Weather conditions were proper for good hemp biomass production. Depending on the selected cultivars, the optimal fertilizer rate was in the range of 90 - 150 kg ha-1. Industrial hemp stalk length was significantly (p<0.05) influenced by the applied nitrogen fertilizer rate and cultivars. The highest stalk length was observed in the cultivar 'Futura 75' under all nitrogen fertilizer rates. The highest stalk length (3.18 m) had reached under the nitrogen fertilizer rate 150 kg ha-1 at 138 growing day from sowing. At the beginning of growing season (June - July) the growth intensity of hemp stalk length is high. Within one month the stalk length grew up for 1.23 meters of cultivar 'Futura 75'. The intensive growth of hemp stalk declines when the lowering stage is reached. Flowering stage occurred in early August, and it was dependent on nitrogen fertilizer rate. Under higher nitrogen fertilizer rate the lowering stage reached later. [ABSTRACT FROM AUTHOR]

Linseed and fibre flax (Linum usitatissimum L.), hemp (Cannabis sativa L.), sunflowers (Helianthus annuus L.) and reed canary grass (Phalaris arundinacea L.) are grown in Latvia, and these bioenergy crops can be used for the production of solid fuel. Some oilseed crops have large perspective for biofuels. Sunflowers, canary seed and hemp have large biomass, but flax and sunflowers have high calorific value. The ash content is quite high in all plants sheave. Linseed can be used not only for obtaining linseed oil, but also for obtaining solid fuel (briquettes, linseed pellets) from straws. Within the framework of this research 2 sunflower varieties, 11 oil and 3 fibre flax samples, 2 reed canary grass varieties and 10 varieties of hemp 2009 and 2010 were studied in the years. The aim of the research was to evaluate the variety of plant biomass qualitative properties for production of solid fuel. All of these bio-energy plants were studied for the following parameters: biomass content, moisture content of dry matter, ash content of dry material, calorific value, sulphur and chlorine content. The quantity of plant biomass yield depends on many factors. Harmful substances in almost all plants make approximately from 0.15 to 0.22% of dry matter. The average highest calorific value at V=const for dried fuel at 105°C of sunflower dry matter was 20.6 MJ·kg-1, and of fibre flax - 18.5 MJ kg-1. The growing of hemp is beneficial to the environment, and hemp is also a good resource as a biofuel. By choosing suitable plants, high dry matter biomass solid fuel products can be obtained. [ABSTRACT FROM AUTHOR]

Oregano (Origanum vulgare L.) is one of the most popular spice and medicinal plants of untraditional horticulture in Latvia. Wild populations of this plant are too few. That is why it is necessary to cultivate oregano for keeping the biodiversity of Latvian nature. It is important to use local oregano genetic resources in agrocenosis as well as to get as rich and qualitative yield as possible. The aim of this research was to explore the parameters of oregano inflorescence in Latvia and to recommend the most productive clones for cultivation. In summer 2011, a total of 45 oregano clones from an ex situ collection of spice and medicinal plants of the Laboratory of Cultivated Plants and Apilogy (Jelgava, Strazdu Street 1) were analysed. Such inflorescence parameters as length and width were explored. The average length of inflorescence of all clones was 17.99 cm, and the average width was 5.74 cm. The results showed that the clone No 26 had the largest width of inflorescence (9.6 cm), but the clone No. 2 had the largest length of inflorescence (31.1 cm). Using oregano Draft Descriptor List, the inflorescence was characterized as short, medium or long. The variability between clones was significant (p<0.05), but between samples of each clone -- non-significant (p>0.05). It is recommended to grow oregano clones No. 2, 5 and 26 in agrocenosis as the most productive. [ABSTRACT FROM AUTHOR]

Future perspective of the research is the production of fuel pellets from energy plant (Phalaris arundinacea L., Festuca arundinacea, etc.) biomass, because it can be better burnt in granule burners and is more environmentally friendly, if compared to the fossil mineral resources (coal, oil, gas), moreover it has low moisture content (70-90 g kg-1) and correspondingly it produces higher combustion energy. The research covered preparation of various content tablets from reed canary grass (Phalaris arundinacea L.) variety 'Marathon' (N fertilizer rate on the N-90 kg ha-1), energy wood -- osier (Salix viminalis L) and poplar (Populus tremula L.) with N fertilizer norms N-0 and N-120 kg ha-1, and afterwards research of the combustion ability of and ash content in these tablets. Combustion ability of reed canary grass (Phalaris arundinacea L.) variety 'Marathon' reached 17.48 MJ kg-1. The highest average combustion ability with different pellet content was found for the fast-growing poplar both with doses of N fertilizer -- 18.55 MJ kg-1 and without N fertilizer -- 18.49 MJ kg-1. Optimum content of various component pellets for biomass was a mixture of components 1/3 (reed canary grass/osier or poplar). The lowest indicators in respect to the ash content were observed for osier (Salix viminalis L.) -- 27.9 g kg-1. The best ash content indicators for a mixture of granular composition was in a mixture of components one-fourth of the reed canary grass with three parts of osier -- 34.3 g kg-1 or with poplar -- 41.8 g kg-1. [ABSTRACT FROM AUTHOR]

Oil-flax has a wide range of utilization possibilities, inclusive of bioenergy production. In our research evaluated out two oil-flax varieties 'Scorpion' and 'Flanders' after the calorific value, oil, lignin, and ash content; and also the chemical composition in 2008 -2010. The results show that oil-flax shoves have a high calorific value and high lignin content but a low temperature for ash fusion. It was established that the growth year and some unexplored factors have influence on the ash content. The oil content in the seeds was 336-458 g kg-1, depending on the chosen variety. The flax shoves can be used as a supplement for biofuel combustion, as they have a low fusion temperature, a high calorific value, but a comparatively low yield makes oil-flax unprofitable to grow for biofuel production. [ABSTRACT FROM AUTHOR]

The productivity of grasslands and pastures mostly depends on cultivated grass varieties. Festulolium (xFestulolium Asch. & Graebn.) is among the most persistent and productive grasses used in many European countries, especially in adverse environments. The aim of the present research was to study photosynthesis activity and crop yield of local and foreign varieties of festulolium and hybrid ryegrass (Loliumxboucheanum Kunth.) under agro-ecological conditions of Latvia. The most significant indices of photosynthetic activity -- leaf area index (LAI) and net photosynthesis productivity (NPP) -- during growth period till first cut were investigated. Field trials were established on sod-gleyic soil (Luvic Epigleyic Phaeozem (Calcaric) -- WRB 2006), fine sandy loam; fertilizers -- 120 kg ha-1 of N, 78 kg ha-1 of P2O5, and 90 kg ha-1 of K2O. The average NPP for festulolium, hybrid ryegrass and perennial ryegrass varieties varied from 5.63 to 8.29 g m-2 day-1. No positive correlation between NPP and dry matter (DM) yield was established. The average LAI was within the range of 1.94-2.91, and a relationship between LAI and DM was found. [ABSTRACT FROM AUTHOR]

New hybrid grasses have been introduced in Latvia recently. Hybrid ryegrass (Loliumxboucheanum Kunth.), considered an ideal grass for European agriculture, is not sufficiently robust to meet many of environmental challenges that face extensive agriculture in less favoured areas. New opportunities for forage production using intergeneric hybrids between more distantly related ryegrass and fescue species have been identified. Diversity of factors controlling festulolium (xFestulolium Asch. & Graebn.) productivity is discussed in many researches. Using intergeneric hybrids, the identification of major factors controlling productivity and feeding value is complicated because of the numerous traits characteristic of their progenitor species. Parental species traits and potential of intergeneric hybrids have been investigated to determine the main factors that influence grass growth and quality, such as nitrogen fertilization, grazing and cutting management, climatic factors and sward age. The importance and potential of new grass species have been analysed. The main target for introgression has been the introduction of biotic and abiotic stress tolerance from Festuca spp. into Lolium spp. Festulolium can show completely novel characteristics, but mostly they are expressed intermediarily. Some varieties are more like ryegrass and some more like fescue, depending on the breeding effort following the cross. Cultivars of festulolium are promising species of fodder grasses in Latvia. Due to its competitive productivity festulolium may be equally ranked with the main forage grasses such as meadow fescue grown in the climatic zone of Latvia. [ABSTRACT FROM AUTHOR]

Grain after enzymatic treatment, which is a starch-containing raw material, is used for ethanol production. Bioethanol production in Latvia began in 2006. Extraction of biofuels is a clean process, because the byproduct is used in various sectors of the economy. The bioethanol in Latvia was derived primarily from winter wheat, winter rye, and winter triticale. The objective of the research is to determine the different nitrogen fertiliser rates required for winter cereal crop yields and bioethanol outcome. The trials were carried out from 2005 to 2008 in Agricultural Science Centre of Latgale (Latvia). The method (ethanol outcome) is based on fermentation of saccharine cereal samples by yeast saccharin chervils followed by the calculation of ethanol outcome and speed of fermentation. The highest starch content was in winter wheat and winter critical grain, but the lowest - in winter rye grains. A close negative correlation (cp<0.05) was found for winter critical and winter wheat between the ethanol outcome and thousand grain weight. Production of biotechnology from rye starch content is used with full utilization of grain. The winter wheat has the largest ethanol outcome from one hectare. [ABSTRACT FROM AUTHOR]

There is a need to find acceptable crops for energy production for the climatic and soil conditions of Latvia. Average annual dry matter yields from fodder red canary grass, oats and barley mixed or maize vary 7- 11.2 t ha-1, 5-8 t ha-1 or 12-16 t ha-1 under the climatic conditions of Latvia. Reed canary grass (Phalaris arundinacea L), oats-barley silage and maize silage were investigated for biogas production in anaerobic digestion process in 6 digesters of volume 51 operated in batch mode at the temperature of 38°C. Average biogas yields from reed canary grass, oats-barley silage or maize silage was 263 1 kgVSd-1, 527 1 kgVSd-1 or 553 1 kgVSd-1 respectively. Average methane content was 48 %, 56 % or 53 % in biogas from reed canary grass, oats-barley silage or maize silage respectively. [ABSTRACT FROM AUTHOR]

The purpose of the research was to analyze the composition of maize and grass silages and estimate influence of forage: concentrate ratio on milk yield in dairy cows. Data were collected in 2013 and 2014 and consist of 11 samples of maize silage and 15 samples of grass silage. Dry matter (DM) content was not significantly different between years within silage group. Dry matter content of maize silage was 317.2 ± 15.14 g kg-1 in 2013 and 361.5 ± 20.61 g kg-1 in 2014, whereas corresponding DM in grass silage was 303.8 ± 17.58 g kg-1 and 361.5 ± 20.61 g kg-1. Crude protein content of DM was significantly higher in grass silage than in maize silage and ranged from 123.9 ± 8.07 g kg-1 to 137.5 ± 7.12 g kg-1. Net energy for lactation (NEL) was significantly higher in maize silage than in grass silage and ranged from 6.5± 0.09 MJ kg-1 to 6.6 ± 0.06 MJ kg-1 of DM (P<0.05). Neutral detergent fiber (NDF) and acid detergent fiber (ADF) content of DM was lower in maize silage than in grass silage. The range in NDF was from 444.1 ± 12.40 g kg-1 to 487.1± 17.79 g kg-1, whereas corresponding ADF ranged from 252.9 ± 7.76 g kg-1 to 254.4 ± 7.76 g kg-1. The relationship between NEL and DM content was: NEL=0.0007xDM + 6.3317. Highest forage: concentrate dry matter ratio was 1.24 in May, 2013, whereas highest milk yield was observed in May, 2014. [ABSTRACT FROM AUTHOR]

Oregano (Origanum vulgare L.) is a paramount medicinal plant in Europe. It is necessary to select the most productive accessions for cultivation. The aim of this research was to explore the fresh and air-dry biomass of oregano. The samples for experiment were selected from an ex situ collection of spice- and medicinal plants (latitude: N 56°39'47"; longitude: E 23°45'13"). It is a fundamental collection in Latvia, attached to the Latvia University of Agriculture, Laboratory of Cultivated Plants and Apilogy (Jelgava, Strazdu iela 1). In spring 2012, oregano accessions from this collection was propagated by cloning and grown in the field conditions. At this moment there are 44 accessions of oregano, planted in 4 rows, each accession in 10 repetitions. The accessions are in random order. In summer 2012-2014, stems had been cut, the data were recorded on fresh biomass. The samples had been dried at +26 °C temperature, the data were recorded on air-dry biomass. The average fresh biomass per plant was 12.72 g in 2012, 127.50 g in 2013 and 195.08 g in 2014. The average air-dry biomass per plant was 5.11 g in 2012, 55.90 g in 2013, 77.96 g in 2014. The results showed that the variability between years and between accessions was significant (p<0.05), but the variability between plants of each accession was not significant (p>0.05). [ABSTRACT FROM AUTHOR]