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Kirje Eesti aasta muld 2025 on Klibumuld(Eesti Maaülikool, 2025) Kõlli, Raimo; Kauer, KarinFor the Year 2025 Soil of Estonia by the Estonian Soil Science Society (ESSS) was elected Skeletic Regosol (as named by World Reference Base for Soil Resources (WRB)), which is one of subspecies of Coarse Rich Ryhky Soils (by Estonian Soil Classification (ESC)). Although these soils form less than 0,2% from the whole soil cover of Estonia, they merit an attention from the aspect of peculiarities of their forming, which have been taken place on narrow coastal area on the border between sea and mainland. Skeletic Regosols have been formed only on these littoral areas, which is rich mainly in coarse calcareous earth materials as limestone or dolomite containing also small stones (ryhk, pebble, shingle) and large stones. Besides that, these soils are as well rich in different kind of eruptive rocks of the size of small and large stones. The most part of Skeletal Regosols’ coarse fraction was formed under the influence of breaking waves, which were induced by strong sea winds. The main criteria of Ryhky Soils’ identification after ESC are the content and shape of small stones (Ø 1‒10 cm), water regime of soil cover, and fabric of soil profiles. Ryhky soils are divided into subspecies by the by the shape of small stones. In ryhky soils among others the ryhk fraction is dominated, but in Pebble soils the pebble and in Shingly soils the shingle fractions are dominating. In the development of Skeletic Regosols or of Shingle soils two development stages is separated. During the first Skeletic Regosols’ abnormal development stage only the primitive shingle rich parent material for these soils have been formed on the border area between mainland and sea. But during this period the soil forming processes are practically absent. During the second development stage of Skeletic Regosols development ie. after with draw of sea water the normal soil forming processes are taken place. As a result of this are formed humus horizons and activated biological cycling on chemical elements and others. In the article the soil forming conditions, coarse earth’s fractions shape and size, development stages of soil profiles, as well soils productivity, humus status, distribution, and agrochemical properties are treated.Kirje Eesti erosioonist häiritud muldade orgaanilise süsiniku- ja lämmastikusisaldus(Estonian Academic Agricultural Society, 2020) Kõlli, Raimo; Kauer, Karin; Tõnutare, Tõnu; Eesti Maaülikool. Põllumajandus- ja keskkonnainstituut. Mullateaduse õppetoolThe work is dedicated to the characterization of erosion-affected soils' (EAS) humus status (HS) in pedo-ecological conditions of South-Eastern Estonia. For understanding HS of EAS their organic carbon (OC) and total nitrogen (NT) sequestration capacities and the ratio C:N was studied by separate soil layers. The average data about soil OC and NT contents (g kg–1) and superficial densities (Mg ha–1) are given by arable soil species. The analysis of reflecting EAS HS on four research areas (Valgjärve, Otepää, Haanja and Mooste) was carried out on the basis of four different origin databases. The analysis of OC content is done by Tjurin and NT by Kjeldahl. In soil associations of erosion-affected areas' the following groups of soils were distinguished: eroded (E), deluvial (D), neutral (N) and non-eroded (En) soils. The HC thicknesses of research area Valgjärve E soils are in limits 18–23 cm, D soils 30–65 cm and of En soils 22–27 cm. The medians of same soils OC concentrations are accordingly 9.4, 11.2 and 10.9 g kg–1 and ratios C:N accordingly 9.8, 9.4 and 10.2. The OC stocks given in the limits of quartiles are in E soils 24–36, D soils 51–143 and En soils 32–49 Mg ha–1. Therefore on eroded areas the perpetual continuums of soil properties' (among these HS) changes may be followed and it is very complicated to separate soil contours on 1:10 000 soil maps. In this work the transitional areas between E and D soils are characterized via N soils. On erosion-affected areas the E and D soils form different soil associations with auto- and hydromorphic normally developed non-eroded soils, where very commonly as well the fluvial (abnormal) soils are presented. The relatively high pedodiversity caused by the areas high geodiversity, is the requisite to the high biodiversity. In erosion-affected regions is extremely important to maintain agricultural activity, as with this is ensured the persistence of naturally beautiful landscapes. The soil cover with EAS acts as accumulator of formed on the same area soil OC.Kirje Effect of crop residue decomposition on soil aggregate stability(MDPI, 2020) Stegarescu, Gheorghe; Escuer-Gatius, Jordi; Soosaar, Kaido; Kauer, Karin; Tõnutare, Tõnu; Astover, Alar; Reintam, Endla; Institute of Agricultural and Environmental Sciences. Estonian University of Life SciencesThe decomposition of fresh crop residues added to soil for agricultural purposes is complex. This is due to di erent factors that influence the decomposition process. In field conditions, the incorporation of crop residues into soil does not always have a positive e ect on aggregate stability. The aim of this study was to investigate the decomposition e ects of residues from two di erent cover crops (Brassica napus var. oleifera and Secale cereale) and one main crop (wheat straw) on soil aggregate stability. A 105-day incubation experiment was conducted in which crop residues were mixed with sandy loam soil at a rate of 6 g C kg1 of soil. During the incubation, there were five water additions. The decomposition e ects of organic matter on soil conditions during incubation were evaluated by determining the soil functional groups; carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4) emissions; soil microbial biomass carbon (MBC); and water-stable aggregates (WSA). The functional groups of the plant residues and the soil were analyzed using Fourier transform infrared spectroscopy (FTIR) and a double exponential model was used to estimate the decomposition rates. The results show that the decomposition rate of fresh organic materials was correlated with the soil functional groups and the C/N ratio. Oilseed rape and rye, with lower C/N ratios than wheat straw residues, had faster decomposition rates and higher CO2 and N2O emissions than wheat straw. The CO2 and N2O flush at the start of the experiment corresponded to a decrease of soil aggregate stability (from Day 3 to Day 10 for CO2 and from Day 19 to Day 28 for N2O emissions), which was linked to higher decomposition rates of the labile fraction. The lower decomposition rates contributed to higher remaining C (carbon) and higher soil aggregate stability. The results also show that changes in the soil functional groups due to crop residue incorporation did not significantly influence aggregate stability. Soil moisture (SM) negatively influenced the aggregate stability and greenhouse gas emissions (GHG) in all treatments (oilseed rape, rye, wheat straw, and control). Irrespective of the water addition procedure, rye and wheat straw residues had a positive e ect on water-stable aggregates more frequently than oilseed rape during the incubation period. The results presented here may contribute to a better understanding of decomposition processes after the incorporation of fresh crop residues from cover crops. A future field study investigating the influence of incorporation rates of di erent crop residues on soil aggregate stability would be of great interest.Kirje The Effect of Plant Residues Management and Fertilization on Plant Growth and Organic Carbon Content in Soil(Eesti Maaülikool, 2012) Kauer, Karin; Raave, Henn (advisor); Viiralt, Rein (advisor)The main hypothesis of present thesis is that the effect of plant residues left on the surface of the sward to decompose on the growth of plants and content of soil organic carbon (SOC) is influenced by the management (fertilization, mowing frequency) and composition of plant species (grasses or white clover). Different effect of residues is based on the variations in their quality that affects the decomposition rate of residues and the amount of recycled C and N. The aims of the study were: (i) to investigate the decomposition of various plant residues left on the sward surface and N mineralization during decomposition. To explain how the decomposition dynamics of plant residues is influenced by their initial chemical composition (N content and C/N ratio); (ii) to investigate the effect of plant residues left on the sward surface to decompose on the growth of herbage; (iii) to investigate the effect of plant residues left on the sward surface to decompose on the content of SOC; also to explain the integrated effects of plant residues and fertilization on the content of SOC. The decomposition rate of plant residues depended on the composition of species in the sward and their developmental stage during the cutting. The different N content of residues due to fertilization did not affect their decomposition rate. Residues with similar N content may decay at different rates because their carbon compounds content is different. The N content of residues is suitable indicator for predicting the amount of mineralisable N because more N was mineralized from residues that had higher N content. The effect of residues on the herbage growth of sward depended on the composition of species and management of swards. The effect was higher in grass-clover sward that was cut less frequently and its yields were higher compared to the turfgrass sward. Returning of turfgrass residues is effective only during the first part of the vegetation period when the sward is sparse showing that the effect of returning the residues may be significantly affected by characteristics such as density and height of plants. Returning of residues in turfgrass sward is effective only when the contact between residues and soil surface is easily attainable. In case of dense sward the residues remain on the top of herbage where they dry and nutrients can’t reach the plants. The herbage growth of sward was increased due to residues only if the N released by residues was sufficient for decomposers as well as for sward growth. The amount of N released by residues depended on the fertilization rate, the amount of residues left to decompose and the composition of species in the sward. The highest effect was seen in returning the residues of grass-clover sward in non-fertilized variant. The effect of plant residues on the sward SOC content and stock depended on the composition of species and management of sward (fertilization and cutting frequency). The turfgrass residues increased the content of SOC significantly more than the residues of grass-clover sward. Fertilization and cutting frequency had an impact on the chemical composition of plants which in turn affected the chemical composition and decomposition of organic material released into the soil.Kirje Maakasutuse, maakasutuse muutuse ja metsanduse sektori sidumisvõimekuse analüüs kuni aastani 2050(Keskkonnaagentuur, Eesti Maaülikool, 2021) Valgepea, Mati; Raudsaar, Madis; Karu, Helen; Suursild, Eve; Pärt, Enn; Sims, Allan; Kauer, Karin; Astover, Alar; Maasik, Martti; Vaasa, Airiin; Kaimre, PaavoKliimaneutraalsuse saavutamiseks 2050. aastaks on oluline kasvuhoonegaaside (KHG) heitkoguste vähendamine ja sidumisvõimekuse suurendamine kõigis sektorites. Et eesmärki täita, tuleb seada selged sihid, hinnates erinevates sektorites KHG heite vähendamise ja sidumise suurendamise potentsiaali ning käsitleda sektori mõju laiemalt ka majanduse konkurentsivõimele. Maakasutuse, maakasutuse muutuse ja metsanduse (LULUCF) sidumisvõimekuse uuring on valminud Keskkonnaministeeriumi tellimusel analüüsimaks kompleksselt LULUCFi sektori KHG sidumisvõimaluste potentsiaali ja ulatust 2030. ja 2050. aasta kliimapoliitika eesmärkide täitmiseks arvestades sealjuures ka pikemaajalist perspektiivi (kuni 2100. aastani). Uuringu käigus kaardistatakse LULUCFi sektori maakasutuskategooriates süsiniku sidumisega seotud aspektid ja tegevused ning hinnatakse nende potentsiaali suurema süsiniku sidumise suunas. Analüüs kirjeldab ning hindab järgmisi LULUCFi sektorit mõjutavaid tegevusi: raportis „Mets ja kliimamuutused“ esitatud raiestsenaariumid (koos puittoodetega); metsakasvatuslikud võtted netojuurdekasvu soodustamiseks: metsade uuenemise tagamine (looduslik uuendus, uuendamine, puuliigi valik), harvendusraie, raieplaanide optimeerimine (täiuse, juurdekasvu ja boniteedi järgi), kuivendamine; metsamaa pind (metsamaa pindala säilimine vähemalt praegusel tasemel) kui süsinikusidumist suurendav tegur: metsastamine, raadamise piiramine/ kompenseerimine; puittoodetesse süsiniku sidumine: puittoodete tootmise suurendamine, puittoodete tootmise struktuuri muutmine pikemaealiste toodete suunas, kohaliku tööstusliku ümarpuidu väärindamine Eestis (sh paberipuu väärtustamine), ümarpuidu import, Eestis varutud puit, puiduenergia kasutus; kasvuhoonegaaside heite vähendamine märgaladelt: jääksoode ehk mahajäetud turbatootmisalade korrastamine, aiandusturbast tulenevate heitkoguste vähendamine; põllumajanduslikud tegevused mulla süsinikuvaru suurendamiseks ja heitkoguste vähendamiseks: orgaaniliste väetiste kasutamine (sh taimejäänuste mulda jätmine), mitmekesisemad ja pikemad külvikorrad, turvasmuldadel põllu- ja kuivendatud rohumaade metsastamine (sh lühikese raieringiga istandused), loodusliku taimestikuga alade loomine (puittaimestiku ribad ja hekid ning agrometsandus), heitkoguste vähendamine turvasmuldadel paiknevatest haritavatest maadest, happeliste muldade neutraliseerimine (lupjamine); asendusefekti hindamine: ülevaade Eesti konteksti sobiva asendusefekti arvutamise võimalikkusest (sh ülevaade teadustekstidest) ja puuduvate või täiendavaid uuringuid vajavate teemade väljatoomine, võimalusel esmaste arvutuste tegemine. Lisaks hinnatakse: kaardistatud meetmete sotsiaalmajanduslikku mõju tegevuste elluviimisel, sh tööhõivet, netotulu ja lisandväärtust. Võrreldakse metsa majandamisega seotud netotulu ja süsinikukaubandusega kaasnevaid potentsiaalseid võimalusi.Kirje Põllumajanduse ja kalanduse valdkonna arengukava aastani 2030 mõjude eelhindamine : lõpparuanne(Eesti Maaülikool, Majandus- ja sotsiaalinstituut, 2019) Viira, Ants-Hannes; Mõtte, Mati; Aro, Kersti; Lillemets, Jüri; Kreegimäe, Katrin; Põder, Anne; Lemsalu, Katrin; Loit, Evelin; Kauer, Karin; Jõudu, Ivi; Roasto, Mati; Jaanuska, Heiki; Järvalt, Ain; Eesti Maaülikool. Majandus- ja sotsiaalinstituutPõllumajanduse ja kalanduse valdkonna arengukava aastani 2030 (PõKa 2030) eelhindamise viis Riigikantselei strateegiabüroo tellimusel läbi Eesti Maaülikool (EMÜ). Projekti algatas Maaeluministeerium (MeM) koostöös Keskkonnaministeeriumiga (KeM). Eelhindamise eesmärk on uurida süsteemselt püstitatud eesmärkide ja sekkumisloogika vastavust ning analüüsida tegevussuundade sotsiaalseid, demograafilisi, majanduslikke (sh põllumajandus, kalandus, vesiviljelus, toidutööstus), keskkonna-, regionaal- ning maaelu-, julgeoleku-, administratiiv- ja eelarvemõjusid. PõKa 2030 rakendamisega kaasnevate mõjude analüüsi koostamisel lähtuti Justiitsministeeriumi ja Riigikantselei koostatud mõjude hindamise metoodikast. Mõjude analüüsi kaasati lisaks eelhindamise projektimeeskonnale valdkondade eksperte. Eelhindamine viidi läbi perioodil 13. august 2018 kuni 30. september 2019. Eelhindamine teostati PõKa 2030 eelnõu versioonile seisuga 25. aprill 2019 ning viidi läbi PõKa 2030 eelnõuga samal üldistuse astmel. Eelhindamine ei hõlma kompleksselt arengukava keskkonnamõjude hindamist. Keskkonnamõjude strateegiline hindamine viidi läbi paralleelselt teise hindaja poolt.Kirje Põllumajandusliku maakasutuse muutuse analüüs sõltuvalt tulevikustsenaariumitest : uuringu lõpparuanne(Eesti Maaülikool, 2023) Viira, Ants-Hannes; Kauer, Karin; Melts, Indrek; Jürgenson, Evelin; Maasikamäe, Siim; Rasva, Marii; Põdra, Kätlin; Lillemets, Jüri; Ariva, Jelena; Azadi, HosseinUuringu „Põllumajandusliku maakasutuse muutuse analüüs sõltuvalt tulevikustsenaariumitest“ eesmärk on luua stsenaariumid põllumajandusliku maakasutuse võimalike muutuste kohta ja analüüsida nende muutuste peamisi mõjutegureid. Analüüs toetab põllumajanduspoliitika otsustusprotsessi, aidates kujundada põllumajandusmaa edasist kasutamist, toidujulgeoleku tagamist ning vastavate meetmete väljatöötamist. Analüüsi tulemusena suureneb maakasutusest ja maakasutuse muutusest tulenevate KHG heitkoguste analüüsimise võimekus. Uuringu I etapis vastati küsimusele: „millised on Eestis põllumajandusmaa kasutamise võimalikud tulevikustsenaariumid võttes arvesse globaalseid trende ja mõjusid ning regionaalseid strateegilisi valikuid põllumajanduse arendamisel?“. Selleks kaardistati poliitikadokumentide, teadus-kirjanduse ja fookusgrupi arutelude põhjal põllumajandusliku maakasutuse muutuse mõjutegurid ja analüüsiti põllumajandusliku maakasutuse muutusega seotud võimalikke positiivseid ja negatiivseid arenguid. Nendele tuginedes loodi viis alternatiivset põllumajandusliku maakasutuse stsenaariumit aastani 2050. Uuringu II etapis loodi viie põllumajandusliku maakasutuse tulevikustsenaariumi kohta andmestik, kaardikiht ja illustreerivad kaardid, kus on esitatud erineva väärtusega põllumajandusmaade paiknemine ning alad, mis sobiksid elurikkuse toetamiseks, metsastamiseks või taastuvenergia tootmiseks. Samuti illustreeriti kaartide abil kõigis stsenaariumites toimuvaid maakasutuse muutusi. Põllumajandusmaa põllumajandusliku kasutuse potentsiaali hindamiseks koostati koondnäitaja, mis võtab arvesse põllumassiivi mullaviljakust, pindala, põllukontuuri kuju (kompaktsust), kaugust lähimast teest, kaugust suurimast asulast, kaugust lähimast põllust ja reljeefi iseloomustavat konarlikkuse koefitsienti. Koondnäitaja väärtus määrati kõigile andmestikus olevatele massiividele. Uuringu III etapis täpsustati stsenaariumeid ja kaardikihte vastavalt eelnevates etappides saadud tagasisidele ning analüüsiti põllumajandusmaa kasutamist ja säilitamist, sotsiaalmajanduslikku ja looduskeskkonna arengut ning KHG heitkoguseid erinevates stsenaariumites. Samuti koondati soovitatavad sekkumismeetmed positiivsete maakasutuse muutuste soodustamiseks ning negatiivsete maakasutuste muutuste ära hoidmiseks. Uuringu lõpparuande esimene peatükk annab ülevaate uuringu temaatikast. Teine peatükk annab ülevaate kasutatud metoodikast. Kolmandas peatükis esitatakse ülevaade põllumajandusliku maa- kasutuse suurematest muutustest Eestis aastatel 1990‒2018. Neljandas peatükis analüüsitakse põllumajandusliku maakasutuse mõjutegureid ning viiendas peatükis on esitatud viis põllumajandusliku maakasutuse võimalikku tulevikustsenaariumit 2050. aasta perspektiivis koos maakasutust ja selle muutust iseloomustavate illustreerivate kaartidega. Kuuendas peatükis esitatakse põllumajandusmaa põllumajandusliku kasutuse potentsiaali illustreerivad kaardid ning analüüsitakse põllumajandusmaa sobilikkust metsastamiseks ja energia tootmiseks. Seitsmendas peatükis esitatakse viie stsenaariumi KHG heitkoguste ja põllumajandustoodangu prognoosid. Kaheksandas peatükis on esitatud lisainfo järgmistes olulistes põllumajandusliku maakasutuse tulevikku puudutavates küsimuses – sügavatel turvasmuldadel asuva põllumajandusmaa kasutamine, agrometsandus ning kohalikele kogukondadele maakasutust puudutavates küsimustes suurema kaasarääkimise õiguse loomise võimalused. Üheksas peatükk võtab kokku poliitikasoovitused põllumajandusliku maakasutusega seotud positiivsete muutuste soodustamiseks ja negatiivsete muutuste pidurdamiseks. Uuringu töörühm tänab kõiki fookusgrupi aruteludes osalenud, küsitlustele vastanud, kirjalikku ja suulist tagasisidet andnud eksperte ning uuringu juhtkomisjon.Kirje Water satability of soil aggregates in a 50-year-old soil formation experiment on calcareous glacial till(Pleiades Publishing, Ltd., 2020) Are, Mihkel; Kauer, Karin; Kaart, Tanel; Selge, Are; Astover, Alar; Reintam, Endla; Institute of Agricultural and Environmental Sciences. Estonian University of Life Sciences; Institute of Veterinary Medicine and Animal Sciences. Estonian University of Life Sciences,Soil formation on the human time scale is immensely time consuming, although it can be significantly accelerated through the effects of vegetation. The content of water-stable aggregates (WSAs) is a useful indicator for determining both the soil development level and the soil quality. However, in severely degraded soils, especially in the Baltic pedoclimatic region, the effects of vegetation on the aggregate stability have been poorly studied. Therefore, to obtain more knowledge about the impact of vegetation on WSA, and thereby knowing how to improve it, this study was conducted on a long-term soil formation experiment in Estonia near Tartu. In 1964, the initial soil from an area of 20 × 8 m down to 100 cm depth was replaced with a sandy loam calcareous glacial till. The experiment started on April 26, 1965, when plants were sown on the plot. The topsoil (0–20 cm) samples were analyzed in 1966, 2000, 2007, and 2014. The study indicated that perennial grasses (meadow fescue and common meadow-grass) fertilized with P40K75, compared to N150P40K75, decreased the WSA content, as well at the accumulation rate of soil organic carbon (SOC) and the total nitrogen content (Ntot). The hybrid alfalfa treatment resulted in the significantly highest SOC and Ntot accumulation, but not in the overall highest WSA content. Under barley, manure positively affected the WSA and SOC, though many other physical properties were not improved. Compared to the initial till under bare fallow, the SOC and Ntot contents were significantly higher under grown crops, but the WSA content remained the same. In addition, regardless of the grown crops, the WSA of larger (0.25–2 mm) aggregates was substantially higher than that of smaller (0.25–1 mm) aggregates. Also, as the relationship between WSA and SOC in the study was linear, the soil was far from C saturation and still in development. Overall, it can be concluded that the cultivation of perennial grasses and hybrid alfalfa on the severely eroded soil is the most rational option to improve the water stability of aggregates and increase the SOC and Ntot contents. However, because of the complexity of the aggregation process, further research is still needed.