5 research outputs found
Promocijas darbs
Promocijas darbÄ pÄtÄ«tas augsnes virskÄrtas morfoloÄ£iskÄs Ä«paŔības (atbilstoÅ”i EHFRB humusa formu klasifikÄcijai), organisko vielu saturs, padziļinÄti pÄtÄ«ts augsnes humusvielu sastÄvs un Ä·Ä«miskÄs Ä«paŔības. PÄtÄ«juma rezultÄti liecina, ka sausieÅu mežos LatvijÄ organiskajÄm vielÄm relatÄ«vi bagÄtu augÅ”Åu (mull humusa formas) telpisko izplatÄ«bu nosaka glacigÄnie un glaciolimniskie nogulumi. LauksaimniecÄ«bas zemju apmežoÅ”anÄs procesÄ organisko vielu uzkrÄÅ”anÄs augsnes virskÄrtÄ sÄkas 30 gadus pÄc apmežoÅ”anÄs, augstÄkÄ C krÄja ir 60 lÄ«dz 100 gadus vecu meža zemju augsnÄs. PalielinÄts koku nobiru Ä«patsvars meža attÄ«stÄ«bas gaitÄ augsnÄ veicina fulvoskÄbju Ä«patsvara pieaugumu, kÄ arÄ« augsnes humÄ«nskÄbju humifikÄcijas, aromatizÄcijas pakÄpes un molekulmasas pieaugumu. AtslÄgas vÄrdi: augsne, humusa forma, apmežoÅ”anÄs, organiskais ogleklis, humusvielasThe doctoral thesis presents a research on the topsoil, its morphological properties (according to the EHFRB humus form classification), and organic matter, focusing on the composition and the chemical properties of the soil humic substances. The results indicate that in forests formed on dry mineral soils in Latvia the spatial distribution of soils which are relatively rich in organic matter (mull humus form) is related to glacigenic and glaciolimnic deposits. The afforestation of agricultural lands leads to the accumulation of organic matter in the topsoil which starts 30 years after the establishment of the forest. The highest organic carbon stock can be observed in 60- to 100-year-old forest land soils. An increased amount of woody debris in the process of forest growth produces an increase in the proportion of fulvic acid, humification rate, aromaticity and molecule weight of the soil humic acids. Key words: soil, humus forms, afforestation, organic carbon, humic substancesDarba izstrÄdÄÅ”anai saÅemts Eiropas SociÄlÄ fonda projekta
āAtbalsts doktora studijÄm Latvijas UniversitÄtÄā Nr. 2009/0138/1DP/1.1.2.1.2/09/IPIA/
VIAA/004 finansiÄls atbalsts. Promocijas darbs izstrÄdÄts arÄ« ar ES SociÄlÄ fonda un
Latvijas UniversitÄtes snieguma finansÄjuma projekta āKlimata pÄrmaiÅas un dabas
resursu ilgtspÄjÄ«ga izmantoÅ”anaā (ZD2016/AZ03) finansiÄlu atbalstu
A global perspective on soil science education at third educational level; knowledge, practice, skills and challenges
The pivotal role of soil as a resource is not fully appreciated by the general public. Improving education in soil science represents a challenge in a world where soil resources are under serious threat. Todayās high school students, the worldās future landowners, agriculturalists, and decision makers, have the potential to change societyās apathy towards soils issues. This research aimed to compare the level of soil education in high and/or secondary schools in forty-three countries worldwide, together comprising 62% of the world's population. Comparisons were made between soil science content discussed in educationally appropriate textbooks via a newly proposed soil information coefficient (SIC). Interviews with teachers were undertaken to better understand how soil science education is implemented in the classroom. Statistical analyses were investigated using clustering. Results showed that gaps in soil science education were most commonly observed in countries where soil science is a non-compulsory or optional subject. Soil science concepts are predominantly a part of geography or environmental science curricula. Consequently, considerable variability in soil science education systems among investigated countries exists. Soil information coefficientās outcomes demonstrated that a methodological approach combining textbooks and the use of modern digitally based strategies in the educational process significantly improved soil education performances. Overall, soil science education is under-represented in schools worldwide. Dynamic new approaches are needed to improve pivotal issues such as: i) promoting collaborations and agreements between high school and universities; ii) encouraging workshops and practical exercises such as field activities; and, iii) implementing technology tools. This, in turn, will prepare the next generation to contribute meaningfully towards solving present and future soil problems
Farmland afforestation effects on soil humus
Å ajÄ pÄtÄ«jumÄ ir aplÅ«kots augsnes organiskÄ oglekļa daudzums dažÄdÄs lauksaimniecÄ«bas zemju ainavu aizaugÅ”anas sukcesijas stadijÄs un dažÄda vecuma meža, bijuÅ”ajÄs lauksaimniecÄ«bas zemÄs LatvijÄ.
PÄtÄ«jumÄ ir noskaidrota lauksaimniecÄ«bas zemju apmežoÅ”anas, kÄ arÄ« citu faktoru ietekme uz augsnes organisko vielu saturu un humifikÄciju. PÄtÄ«juma gaitÄ konstatÄts, apmežoÅ”anai ir bÅ«tiska ietekme uz organisko vielu saturu augsnes minerÄlslÄnÄ« lÄ«dz 10 cm dziļumam.
TÄpat veicot augsnes paraugu analÄ«zi konstatÄts arÄ«, ka ApmežoÅ”ana bÅ«tiski ietekmÄ arÄ« organisko vielu humifikÄcijas pakÄpi augsnes A horizontÄ.
AtslÄgas vÄrdi: augsnes organiskÄs vielas, apmežoÅ”ana, humifikÄcija.In this research work is examined the amount of organic carbon in soil in the agricultural landscape in different phases of overgrowing successions and of different ages in forest soil ā in former farmlands in: Latvia.
In the research is found out the influence of farmlandās afforestation as well as the influence of other factors on the content of soilās organic substances and humification. During the researh was made a conclusion that afforestation has a significant influence on the content of soilās organic substances in soil mineral layer in the depth of 10 cm.
As well as analysing the samples of soil was found out that afforestation substantially influences the level of humification of organic substances in the A horizon of the soil.
Keywords: soil organic matter, afforestation, himificatio
Changing character of the organic matter in a raised bog peat
DarbÄ ir aplÅ«koti humifikÄcijas procesi Eipuru, Dzelves, AugstÄ Kalna un Buļļu purvu kÅ«drÄ. Bakalaura darbÄ pÄtÄ«ts kÅ«dras humifikÄcijas process atkarÄ«bÄ no kÅ«dras kolonas atraÅ”anÄs vietas, kÅ«dras sastÄva un cilvÄka ietekmes. HumifikÄcijas procesa raksturoÅ”anai ir izmantoti Å”Ädi rÄdÄ«tÄji: humÄ«nskÄbju/fulvoskÄbju attiecÄ«ba, fluorescences intensitÄtes attiecÄ«ba I460/I510 un E4/E6 attiecÄ«ba. PÄtÄ«jumÄ konstatÄts, ka humifikÄcijas procesi kÅ«drÄ ir intensÄ«vÄki kÅ«dras aerÄcijas zonÄ, tos stipri ietekmÄ cilvÄka darbÄ«ba, kÄ arÄ« tas, ka humifikÄcijas procesus vienlÄ«dz labi raksturo gan humÄ«nskÄbju/fulvoskÄbju attiecÄ«ba, gan I460/I510 attiecÄ«ba.
AtslÄgas vÄrdi: augstais purvs, humifikÄcija, humÄ«nskÄbes, fulvoskÄbes, fluorescences intensitÄte, E4/E6 attiecÄ«ba.Paper covers questions about the humification proceses in Eipuru, Dzelves, AugstÄ Kalna and Buļļu rised bogs, related with sampling state position, peat composition and effect of human activities. To describe humification proceses, was used: humic acid/fulvic acid ratio, fluorescence intensity ratio I460/I510 and E4/E6 ratio. In study was find out, that humification intenses in aeration zone, it has effect on human activities, and that both humic acid/fulvic acid ratio and I460/I510 ratio are good humification indices.
Keywords: raised bog, humification, humic substances, fluorescence intensity, E4/E6 ratio
Effects of afforestation of agricultural land with grey alder (Alnus incana (L.) Moench) on soil chemical properties, comparing two contrasting soil groups
Abstract Background Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties. Results The results were analysed using analysis of variance. During the first 25āyears after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+ and available P in the topsoil (0ā10ācm and 11ā20ācm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+ concentration decreased and exchangeable Fe3+ and Al3+ concentration increased. Conclusions The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern