The impact of the termination technology of agro-ecological service crops on soil properties in open field vegetable production

ArticleThe agro - ecological service crops (ASC) are introduced in the agro - ecosystems to provide or enhance ecological services, thus promoting the whole soil - plant system equilibrium. To avoid competition with the subsequent cash crops, the growth of the interposed ASC is terminated in advance of the cash crop planting. The traditional, most widespread technique to terminate the ASC is incorporation as green manure into the soil by tillage (GM). However, since tillage includes energy and labour consuming and soil dis turbing operations, the use of no/reduced tillage techniques (as the roller crimping technology - RC) has received increasing interest. An international research consortium (SOILVEG) including Estonian Crop Research Institute, was established in 2015 with th e aim to study among others the impact of ASC termination on soil dry bulk density (BD), water content, soil structure and microbiological activity. Data are collected from Estonian tri als in 2016 and 2017 at Jõgeva. The physical properties of 0 – 40 cm soil layers were determined. Higher BD in soil layers (0 – 20 cm) of plots with ASC and RC was determined comparing to the GM and control plots. Bigger water content in same layer of plots with ASC and the RC was determined comparing to the GM plots. The use of the ASC - s helped to arise ratio of agronomically preferred soil particles. Microbial activity was estimated by assessing of enzyme dehydrogenase activity in 0 – 20 cm soil layer. There were no statistically relevant differences in soil dehydrogenase activit y (DHA) be tween the RC and GM treatments

Fodder galega (Galega orientalis Lam) grass potential as a forage and bioenergy crop

ArticleFodder galega (Galega orientalis Lam.) is a forage legume that has been grown in Estonia for almost forty five years. Pure galega is known to be persistent, high-yielding crop and rich in nutrients, in particular crude protein (CP), neutral detergent fibre (NDF) and acid detergent fibre (ADF). Galega is usually grown in a mixture with grass in order to optimize its nutrient concentration, increase dry matter (DM) yield and improve fermentation properties. The trial plots were established on a typical soddy-calcareous soil. There are certain grass species suitable for the mixture. In this study galega mixtures with reed canary grass cv. ‘Marathon’, timothy cv. ‘Tika’, red fescue cv. ‘Kauni’ and festulolium cv. ‘Hykor’ were under investigation in three successive years (2013–2015). In order to increase competitiveness of grasses and the yield of the first cut, two N fertilization levels were used: N0 and N50 kg ha-1 . Two cuts were carried out during the growing season in all three years. The total dry matter yield varied from 9.1 to 12.8 t ha-1 . The NDF concentration in the DM varied from 495−559 g kg-1 . Both DM-yield and NDF were dependent on the year, mixture, cutting time and fertilization. Nitrogen fertilization (N50 kg ha-1 ) favoured grass growth and reduced the role of galega in the sward

Effects of lake sediment on soil chemical composition, dehydrogenase activity and grain yield and quality in organic oats and spring barley succession

In organic farming, it is important to maintain soil fertility with organic fertilisers; often organic compost, manure, or slurry is used. However, the effects of lake sediment in maintaining and improving soil fertility are less studied. The direct and residual effects of a one-time application of 50 t ha-1 or 100 t ha-1 of lake sediment were compared to an unfertilised control for oats (Avena sativa) (2015) followed by spring barley (Hordeum vulgare) in 2016, under organic farming conditions. Soil chemical composition, microbial activity in the 0–20 cm soil layer, grain yield, and grain quality were tested. The application rate, 100 t ha-1 , increased (P < 0.05) the soil organic carbon (SOC), the amount of mobile calcium (Ca), total nitrogen (Ntot), and boron (B) content in soil. Both application rates increased (P < 0.05) the amount of magnesium (Mg), copper (Cu), and manganese (Mn) content in the soil. The application rate had no effect on soil pH. Soil dehydrogenase activity (DHA) was higher (P < 0.05) at 100 t ha-1 than the control and the lower application rate. Both rates of lake sediment application significantly (P < 0.05) increased the grain yield and test weight for oats in 2015. Positive residual effects on spring barely yield only occurred in the 100 t ha-1 treatments in 2016. No residual impact of lake sediment was found on spring barely quality

Erinevate viljelusviiside mõju mikroobide koosseisule ja aktiivsusele mullas

Liina Edesi thesis „The influence of cultivation methods on soil microbial community composition and activity“ is based on the long-term research, focused on comparison of organic (with and without cattle manure) and conventional (with cattle manure, mineral fertilizers and pesticides) cultivation methods and their impact on the soil microbe community composition (abundance of the total number of bacteria, molds, yeasts, mesophilic spore-forming bacteria, Fusarium spp., actinomytcetes, azotobacteria, cellulose decomposers, denitrifying and nitrifying bacteria) and on soil microbial biomass and activity under field conditions, within the typical Estonian crop rotation. The aim of this study was to investigate the impact of manure, crop and pesticides on the soil microbe community composition and on soil microbial biomass and activity. The results showed that the application of solid cattle manure in organic treatment compared to the organic treatment without manure increased the abundance of the total number of bacteria, yeasts, denitrifying bacteria, and the soil enzymatic activities. The use of solid cattle manure had a positive effect on the abundance of mesophilic spore-forming bacteria, nitrifying bacteria, cellulose decomposers and enzyme phosphomonesterase activity. It was similar in conventional treatments where the mineral fertilizers and pesticides in addition to manure were used. The treatments with cattle manure showed a better ability to suppress Fusarium spp. The cultivation of red clover in crop rotation was promotive to molds, Fusarium spp., as well as to nitrifying bacteria and cellulose decomposers in soil. However, the cultivation of oats inhibited abundance of Fusarium spp. and promoted the abundance of yeasts, which is in antagonistic relationship with Fusarium spp.. In conventional treatment, the use of pesticides (active ingredients – metribuzin, metalaxyl, fluazinam, mancozeb and MCPA) decreased the abundance of total number of bacteria, spore-forming bactera, mold, yeasts, denitrifying bacteria and dehydrogenase activity. However, after a period of time, the population and dehydrogenase activity returned almost to the same level as in organic treatments fertilised with solid cattle manure. The use of pesticides had no influence on the abundance of actinomycetes and nitrifying bacteria in soil. Present research revealed that the use of solid cattle manure in crop rotation increases microbial activity and microbial abundance in the soil, while inhibiting the Fusarium spp. fungal development. Mold incl. Fusarium spp. abundance in the soil decreased during oat cultivation. Despite of decrase of abundance and activity of soil microbes because of use of pesticides, the microbial population was able to recover itself.Liina Edesi doktoritöö „ Erinevate viljelusviiside mõju mikroobide koosseisule ja aktiivsusele mullas“ raames viidi 2007–2013. aastal läbi põldkatse, milles uuriti viieväljalises külvikorras mahepõllumajandusliku (sõnnikuga ja sõnnikuta) ja tavapõllumajandusliku (sõnniku, mineraalväetiste ja pestitsiididega) viljelusviisi mõju mullas elavate mikroobikoosluste mikroobide arvukusele (bakterite üldarv, hallitusseened, pärmid, Fusarium spp., mesofiilsed eosbakterid, nitrifitseerijad, denitrifitseerijad, aktinomütseedid, azotobakterid ja tselluloosilagundajad) ja mulla mikroobsele biomassile ning mikrobioloogilisele aktiivsusele. Doktoritöö eesmärgiks oli välja selgitada milline on taheda veisesõnnikuga väetamise, külvikorras kasvava kultuuri ning pestitsiidide mõju mullas elavate mikroobide arvukusele ning aktiivsusele. Uurimistulemustest selgus, et bakterite üldarv, pärmide ja denitrifitseerijate arvukus ja mikrobioloogiline aktiivsus oli suurim mahepõllumajanduslikus sõnnikuga väetatud variandis ja madalaim mahepõllumajanduslikus sõnnikut mitte saanud variandis. Leiti, et veisesõnnikul oli positiivne mõju nii mesofiilsetele eosbakteritele, nitrifitseerijatele, tselluloosilagundajatele ja seda isegi tavapõllumajanduslikus variandis, kuna nende arvukus oli selles variandis suurem kui veisesõnnikut mitte saanud mahepõllumajanduslikus variandis. Sõnnikuga väetatud mullal avaldus ka suurem Fusarium spp. allasurumise võime. Katsetulemuste põhjal võib järeldada, et ristiku kasvatamine külvikorras soodustas nii hallitussente, sh ka Fusarium spp., nitrifitseerijate kui ka tselluloosilagundajate arengut mullas. Samal ajal kaera kasvatamine pärssis Fusarium spp. seente arvukust, soodustades samal ajal Fusarium spp. seentega antagonistlikus suhtes olevate pärmide arengut. Tavapõllumajanduslikus variandis intensiivne pestitsiidide (toimeained – metribusiin, metalaksüül, mankotseeb, fluasinaam ja MCPA) kasutamine vähendas bakterite üldarvu, mesofiilsete eosbakterite, hallitusseente, pärmide, denitrifitseerijate arvukust ning mikrobioloogilist aktiivsust mullas. Järgmisel kasvuperioodil, kui pestitsiidide kasutamine oli väiksem, mikroobide populatsioon ja mikrobioloogiline aktiivsus mullas taastusid ja jäid praktiliselt samale tasemele, mis oli mahepõllumajanduslikus sõnnikuga väetatud variandis. Katses kasutatud pestitsiidid ei omanud olulist mõju nitrifitseerijate ja aktinomütseetide arvukusele mullas. Läbiviidud uurimistööst järeldus, et taheda veisesõnniku kasutamine külvikorras suurendab mikrobioloogilist aktiivsust ning mikroobide arvukust mullas, samal ajal pärssides Fusarium spp. seente arengut. Hallitusseente sh. Fusarium spp. arvukus mullas väheneb ka kaera kasvatamise korral. Kuigi uurimistöös taimehaiguste, -kahjurite ning umbrohtude tõrjeks kasutatud pestitsiidide tagajärjel mikroobide arvukus ning aktiivsus mullas vähenes, selgus, et kasutatavate pestitsiidikoguste vähenedes oli mikroobide populatsioon võimeline taastuma

The effect of cover crops on biomass and nitrogen accumulation and on spring barley yield

Saabunud / Received 27.05.2023 ; Aktsepteeritud / Accepted 21.06.2023 ; Avaldatud veebis / Published online 15.08.2023 ; Vastutav autor / Corresponding author Merili Toom ; [email protected] crops play an important role in preventing nutrient loss, reducing agricultural inputs, improving soil quality and environmental sustainability. The objectives of the study were to determine the biomass and nitrogen accumulation of cover crops and their effect on the following spring barley (Hordeum vulgare L.). Field trials with cover crop species winter rye (Secale cereale L), winter turnip rape (Brassica rapa spp. oleifera L.), forage radish (Raphanus sativus L. var. longipinnatus), hairy vetch (Vicia villosa Roth), and berseem clover (Trifolium alexandrinum L.) were carried out during four growing seasons (2016/17, 2017/18, 2018/19, and 2019/20) at the Estonian Crop Research Institute (present: The Centre of Estonian Rural Research and Knowledge, METK). Cover crop biomass and N accumulation in autumn and in spring depended on species and growing conditions. The biomass and nitrogen (N) accumulation were at their lowest in the first growing season (2016/17) due to lowest level of effective temperatures. Forage radish accumulated the highest amount of biomass and N in autumn. Berseem clover accumulated lowest amount of biomass and N in the year with drought conditions (2018) before sowing. Among overwintered cover crops, hairy vetch accumulated the highest amount of N in the spring although its biomass was similar to winter turnip rape. Winter rye had the lowest biomass and N accumulation in spring. As an average over the four years, only forage radish and hairy vetch significantly increased the yield of subsequent barley. None of the cover crops had a negative effect on barley, as the yield level following other species was similar to the control without cover crop. The knowledge about cover crop selection is useful to integrate suitable species into Estonian cropping systems

Powdery mildew (Erysiphe cruciferarum) evaluation on oilseed rape and alternative cruciferous oilseed crops in the northern Baltic region in unusually warm growing seasons

The pathogen Erysiphe cruciferarum is an increasingly serious threat to cruciferous oilseed crops worldwide. In the present study, the severity of powdery mildew was evaluated on spring oilseed rape (Brassica napus) and five alternative oilseed crop species (B. juncea, B. nigra, Sinapis alba, Raphanus sativus, Eruca sativa). The main aim of the study was to identify plant species that are less susceptible to powdery mildew for possible application as cover crop, in trap cropping or seed production. Powdery mildew assessments were conducted in two growing seasons that were characterised by unusually warm and dry conditions for northern temperate climatic conditions. In both growing seasons, a heavy powdery mildew infection (over 80%) was recorded on B. napus and B. nigra plants, indicating that E. cruciferarum is an important pathogen for oilseed crops in northern Baltics. However, three other cruciferous species S. alba, E. sativa and R. sativus showed full resistance to powdery mildew, and thus, even under strong powdery mildew pressure, they can be cultivated without pesticide application in northern Baltic conditions. We suggest that in changing climatic conditions powdery mildew is expected to become a more serious problem in cruciferous oilseed crops in northern Europe, especially under intensive short-rotation farming practices

Organic Carrot (Daucus carota L.) Production Has an Advantage over Conventional in Quantity as Well as in Quality

Organic production is one of the fastest growing food sectors globally. However, average yield in organic vegetable production is up to 33% lower than in conventional production. This difference could be due to higher fertilization rates in conventional, compared to organic, farming. We aimed to compare yield and quality characteristics of carrots produced under equal nitrogen fertilization rates over four years in organic and conventional conditions. We found a 14.5% higher marketable, and 10.0% lower discarded, yield in the organic compared to the average conventional treatments. In addition, carrots managed organically had 14.1% lower nitrate and 10.0% higher vitamin C content than carrots managed conventionally. There were no convincing effects of cultivation system on the nitrogen, total sugar, or dry matter content of carrots. Organically managed carrots were free of pesticide residues, while several residues were found in carrots managed conventionally. Our study reveals that organic management of carrots may exceed that of conventional methods in yield and several quality characteristics, while being free of pesticide residues. Organic fertilizer gave an advantage over mineral fertilizer, when equal rates of nitrogen were used in both production systems

Effect of Cirsium arvense L. on soil physical properties and crop growth

The re-cultivation of abandoned areas creates weed control problems. The main problems in these areas are perennial weeds, such as Cirsium arvense L. but this perennial deep-rooted plant may have a beneficial effect on the physical properties of compacted soil. In order to study the effect of C. arvense s root system on soil properties, the field experiment and a survey of arable fields were conducted in Estonia. The soil bulk density and penetration resistance were measured from soils covered by C. arvense or spring barley (Hordeum vulgare L.) on compacted and un-compacted soil. The results showed significantly lower penetration resistance and bulk density underneath C. arvense than under barley in both the field experiment and a field survey on arable soils. The shoot mass of C. arvense was less affected than the shoot mass of barley by soil compaction and was caused by C. arvense s better ability to develop its root system in compacted soil. Wheat yield, on soils affected by C. arvense, was increased by 28% on loose soil and 37% on compacted soil. It may be concluded that in areas affected by deep-rooted weed species, such C. arvense, the soil s physical properties will improve at least in the first two years.vo

Alternaria Black Spot (Alternaria brassicae) Infection Severity on Cruciferous Oilseed Crops

The increase in the cultivation area of cruciferous oilseed crops and the use of short crop rotation has resulted in the enhanced spread of several major pests in Northern latitudes. There is currently limited information about incidence and severity of Alternaria black spot disease (Alternaria brassicae) on the main oilseed crop, spring oilseed rape (Brassica napus), in the Northern Baltics. Thus, spring oilseed rape and five alternative cruciferous oilseed crops were selected and their resistance to black spot disease was evaluated in field conditions during two growing seasons. We hypothesized that spring oilseed rape is more susceptible to Alternaria black spot disease than other alternative cruciferous oilseed crops. Both growing seasons were warmer and drier compared to the long-term average, and were thus suitable for A. brassicae development and assessments. In both years, incidence of Alternaria black spot infection was recorded on all cruciferous species, yet the disease development differed considerably among the crops. During both growing seasons, black mustard (B. nigra) plants were the most infected. Based on our observations during warm growing seasons we conclude that alternative oilseed crops such as Sinapis alba, Eruca sativa and Raphanus sativus are more resistant to the Alternaria black spot infection than the traditional oilseed crops and thus, possess a great potential to grow with limited chemical disease control in Northern Baltic conditions

Different wheat cultivars exhibit variable responses to inoculation with arbuscular mycorrhizal fungi from organic and conventional farms.

The present study aimed to investigate the effects of arbuscular mycorrhizal (AM) fungal communities originating from organic and conventional agriculture on wheat growth and yield. Six different spring wheat cultivars released in different years in north and central European countries were considered. We hypothesised that AM fungal inoculum collected from organic agricultural fields would elicit a greater positive growth response than inoculum collected from conventional agricultural fields; and that older cultivars, which were developed under conditions of low fertilizer input, would exhibit overall greater growth responses to the presence of AM fungi, compared with more recent cultivars, and that AM fungal inoculum from conventional fields might have the most beneficial effect on the growth and yield of recent cultivars. The results showed that the overall effects on the growth and yield of spring wheat grown with organic and conventional AM fungal inocula did not differ greatly. However, the inoculation growth response, showing the difference of the effects of organic and conventional inocula, varied between particular wheat cultivars. Inoculation growth response of the cultivar Pikker (released in 1959) was the most positive, while that of the cultivar Arabella (released in 2012) was the most negative. The use of AM fungal inoculum from organic fields resulted in slightly taller plant individuals. Pikker showed relatively higher yield and stronger growth when the organic AM fungal inoculum was used. Arabella exhibited relatively lower yield and weaker growth when the organic inoculum was used. Whether the positive response of Pikker to Estonian organic inoculation reflects adaptation to the locally occurring AM fungal community needs to be established by further studies of the communities of AM fungi colonizing wheat roots