We spent the year celebrating the State (Latvia 100) and Agriculture higher education (155) anniversaries. We reminded ourselves that life would continue. After the celebrations, and much needs to be done to convince international experts that the importance of agricultural sciences has increased, we are internationally better recognizable, large and powerful in place of many small institutions, their own the articles are submitted to scientific journals and are quoted etc., etc., etc. This year we have collecting all the work done and concluding that the reporting period has indeed been done a lot. The number of publications quoted has increased, the authors have appeared or increased Hirsch Index, foreign colleagues involved to research projects or work in an institution who together make Latvian agricultural science and also scientists more internationally recognizable. The workshop reports presents research results in crop (winter wheat, barley, oregano) cultivation, fertilizers application, plant diseases and pests identification and control. Research in forest stand biomass determination and calculation of carbon sequestration has been viewed. Fertility of Latvian Dark-Headed sheep was analysed. Technology of dehydration of sapropel in geotextile bags has been outlined. Research on influence of soil tillage on clay mineral composition and plasticity has been discussed.

The study was carried out in a long-term experimental field “Sidrabiņi” where liming and fertilizer usage has been studied since 1982. Field experiment includes 4 plots with different fertilizer and liming rates, which are split in 16 smaller plots, where each plot is unique. Totally, four liming rates 0, 2.85, 5.70 and 11.40 t haE−1 CaCO3 and four rates of mineral fertilizers were used: without fertilizer, N45P30K45, N90P60K90 and N135P90K135 were applied annually. Primary liming was done in 1981 using oil shale ash with neutralizing value 80%, the maintenance liming was performed in 1994 (dolomite flour 97.0%) and in 2014 (limestone flour 97.6%). Soil acidity is one of the most important parameters of soil degradation. Soil pH (soil reaction) affects all stages of plant growth. Besides, soil pH is one of the parameters studied in field experiment. Aim of this study was to evaluate obtained data of soil pH changes from long-term field experiments data base.

Heterogeneous populations is one of the ways to increase genetic diversity in varieties of self-pollinating cereals. The aim of this research was to evaluate performance of spring barley (Hordeum vulgare) composite cross population ‘Mirga’ in comparison to three homogenous varieties. Field trials were carried out during 2015–2018 under organic and conventional farming systems. ‘Mirga’ showed a tendency to be more productive under organic conditions and could be characterized as widely adaptable to various growing conditions. Net blotch (Pyrenophora teres) severity was significantly lover for ‘Mirga’ than that of checks under both conditions in most of the cases. Competitiveness against weeds for ‘Mirga’ and checks did not differ.

The aim of this study was to evaluate the development of wheat leaf diseases depending on fungicide treatment. A two-factorial field experiment (A – fungicide treatment (five schemes, including control without fungicide); B – the level of nitrogen fertilization (four levels)) with four replications was carried out in 2019. Disease development during the whole vegetation season was evaluated by calculating the area under the disease progress stairs (AUDPS); and the two-factor dispersion analysis was used to determine the significance of data. Tan spot and Septoria leaf blotch were the most important diseases. The level of nitrogen did not influence the development of leaf diseases; however, the impact of fungicides was significant. All the used fungicide treatment schemes decreased severity of diseases, but differences between variants were not essential in 2019.

The aim of the research was to analyse the impact of sowing rate and row spacing on grain yield and quality of four winter wheat (Triticum aestivum L.) varieties ‘Skagen’, ‘Edvins’, ‘Brencis’ and ‘Talsis’. The field trials with two variants of sowing rate (500 germinate able kernels mE−2 and 300 germinate able kernels mE−2) and two variants of row spacing (12 and 25 cm), when lowest sowing rate was used, were set up at the Stende Research Centre of Institute of Agricultural Resources and Economics in 2017/2018. The results of one year experiments showed that grain yield was lower in all variants with reduced sowing rate (−40%), if compared with the variant, where 500 germinate able kernels mE−2 were used. In opposite, the grain quality indicators (protein and gluten content, also Zeleny index) were higher in variants, where lower sowing rate was used. Winter wheat varieties ‘Brencis’ and ‘Edvins’ characterize with high intensity of productive tillering and it is recommended to reduce sowing rate by 30–40% in optimal sowing time and good environmental conditions.

Sapropel dehydration technology was tested in the geotube from November 2018 to August 2019. Sapropel was collected from Biža Lake, Andrupene Municipality, Krāslava Parish, Latvia. Three moisture sensors were inserted in the geotube in three different depths. Initial absolute sapropel moisture was 90%, relative – 60%. In an experimental time period sapropel was dehydrated to relative moisture 35% (VWC) in a bottom part of the geotube.

One of the evaluation traits of Latvian Dark-head breed breeding was the enhancement of ewes’ fertility which increases the number of lambs per ewe. In current study, 1 054 Latvian Dark-head breed ewes from six ram (Apolons, Ikars, Irbis, Sīgars, Sīmanis, Skaris) lines were selected depending on selection group criteria. Ewes from Skaris (36%) and Apolons (32%) lines were mostly included in the potential selection group population. Oldest ewes were from Sigars and Skaris lines, their age was 4.6±0.17 and 4.1±0.08 years, respectively, but the ewes from Irbis line were significantly younger – 3.2±0.10 years (p is less than 0.05). On average, Latvian Dark-head ewes were from 2.4 to 3.5 parities depending on ram line. Fertility of first two parities’ ewes was in range of 200 to 213.8%, but fertility of third parity ewes decreased (40% of offsprings were born as single). We concluded that ewes from Apolons and Ikars ram lines are characterized by a high and stable fertility.

Yellow rust caused by Puccinia striiformis is one of the most harmful diseases in wheat worldwide. It can cause 10–70% yield loss. In Latvia, only periodic observations of yellow rust have been made. In recent years, epidemics of P. striiformis were observed in wheat-growing regions. New aggressive P. striiformisraces were identified. These races are adapted to high temperatures, produce more spores, and have a shorter latent period. This study aimed to identify the races of P. striiformis in Latvia. In 2017–2019, wheat leaves with symptoms of P. striiformis were collected. Wheat samples were sent to the Aarhus University Global Rust Reference Centre in Denmark for race identification with phenotyping and genotyping methods. During the research, the races of P. striiformis – PstS4, PstS7 (Warrior-), PstS10 (Warrior), PstS13 (Triticale2015) and PstS14 were identified.

Nitrogen fertilizer plays an important role in the production of high yields of winter wheat (Triticum aestivum), but the use of nitrogen amount that does not pose a risk to environment is of constant importance. The aim of this paper is to find out the impact of nitrogen top-dressing rate on winter wheat yield and yield forming components per four year period (2014/2015–2017/2018). The experiment was conducted at the Research and Study farm “Pēterlauki” of Latvia University of Life Sciences and Technologies. Researched factors were eight nitrogen top-dressing rates (N0 or control, N60, N90, N120(90+30), N150(90+60), N180(90+60+30), N210(90+70+50) and N240(120+60+60)), two soil tillage variants(traditional soil tillage with mould-board ploughing at a depth of 20–22 cm and reduced soil tillage with disc harrowing at a depth below 10 cm) and two pre-crops (wheat after oilseed rape (Brassica napus spp. oleifera) and wheat after wheat). Nitrogen top-dressing rate affected average winter wheat grain yield and all tested yield components significantly (p is less than 0.001). Grain yield and 1000 grain weight increased significantly until N top-dressing rate N150. The number of ears per square meter increased significantly until the rate N90, but the grain number per ear and grain weight per ear increased significantly until the rate N120.

Clayey soil’s physical and chemical traits are dependent on many properties – clay-mineral and grain-size composition, hydrological properties, relief, soil tillage, crop rotation. The study is carried out in a long-term monitoring field Poķi at the Research and Study farm “Pēterlauki” of the Faculty of Agriculture of Latvia University of Life Sciences and Technologies, where uniform soil tillage is used since 2009. Three different crop rotation variants in two soil tillage variants (traditional (mould-board ploughing) and reduced (disk harrowing)) were studied. The goal of the study was to identify the influence of long-term uniform soil tillage on clay mineral composition and soil plasticity. First results showed that reduced soil tillage has influence on clay mineral composition and also on soil plasticity.