Ilutaimede kasv ja areng sõltuvalt orgaaniliste lisanditega muudetud mullatingimustest

A Thesis for applying for the degree of Doctor of Philosophy in Agriculture.Väitekiri filosoofiadoktori kraadi taotlemiseks põllumajanduse erialal.Modern plant production results in an intense use of natural resources and chemical inputs, with consequences on the environment. Peat is widely used for ornamental plant propagation and growth in container soilless media, representing 90% of peat-based substrates produced in Europe. Peat production diminishes natural diversity and disrupts the water regime of mined areas. Peatlands, left without vegetation after peat excavation, turn from carbon sinks to sources of greenhouse gas emissions due to higher mineralisation rate. Therefore, it is necessary to find alternative materials for ornamental plant growth. The aim of this PhD thesis is to contribute to the improvement of sustainable horticultural practices and enhance the ornamental value of bedding plants. This thesis studies the reduction of peat use in container growing media and in mulching of landscape areas, by substitution with inorganic and organic materials obtained from organic wastes recycling. In the pre-cultivation stage of ornamental plants, it is possible to substitute peat with values above 50% of the tested hardwood biochar with an additional simultaneous liming effect in container growing medium. Furthermore, in landscape areas, the application of peat as a mulching material can be avoided, by replacement with alternative organic materials such as fresh grass clippings, pine bark, and cocoa bean shell, with an increase of plant ornamental value.Kaasaegne taimekasvatus on seotud loodusvarade, väetiste ning taimekaitsevahendite ulatusliku kasutamisega, mis mõjutab ümbritsevat looduslikku keskkonda. Turvas on enim kasutatud kasvusubstraadi materjale, mis moodustab ligikaudu 90% Euroopas toodetud kasvusubstraatidest. Samas aga rikub turbatootmine looduslikku mitmekesisust ja kaevandatavate alade veerežiimi. Tootmise järel taimestikuta jäänud turbaalad muutuvad seoses turba mineraliseerumisega õhku lenduva süsihappegaasi ja lämmastikdioksiidi allikaks. Seega on oluline leida taimede kasvatamiseks alternatiivseid materjale. Käesoleva uurimistöö keskmes on jätkusuutlike agrotehniliste võtete arendus ilutaimede kasvatamisel, mulla ja kasvusubstraadi omaduste parandamine ja turba asendamine orgaaniliste ning anorgaaniliste materjalidega ja samaaegne orgaaniliste jäätmete utiliseerimine. Ilutaimede ettekasvatamise algstaadiumis saab kasvusubstraadi turvast asendada 50% ulatuses lehtpuu biosöega, mis toimib ka turba happesuse neutraliseerijana. Haljastuses on võimalik turbamultšist loobuda ja asendada see teiste materjalidega nagu muruniitmisjäägid, männikoor ja kakaoubade kestad, mis soodustavad ilutaimede kasvu ja arengut isegi lühikesel kasvuperioodil

Hardwood biochar as an alternative to reduce peat use for seed germination and growth of Tagetes patula

Biochar, a carbon-rich material resulting from pyrolysation, is one of the proposed alternatives as a substrate component to peat. The aim of this study was to investigate the effect of different ratios of peat substitution with a locally available hardwood biochar on the chemical characteristics of growing media, seed germination, plant morphological and nutritional parameters of Tagetes patula. Experimental results show that biochar can be used as a partial peat replacement, showing a complementary liming effect, rising the initial pH of peat (2.8) to values of 4.5 and 7.3 in mixtures with 50% and 75% substitution of peat by biochar, respectively. The mixture with a 50% biochar rate exhibited the strongest change between initial and final pH, rising from 4.5 to 5.7. Increasing content of biochar in the mixtures corresponded to increasing content of total K, Ca, Mg, available K and decreasing level of available Mg. The highest germination percentage was observed in the mixtures with biochar rates from 50% to 100%. Among all substrates, the greatest plant diameter, true leaf area and total root length were measured in the 50% peat substitution mixture, where the highest contents of P, K and Ca in plant shoots were found

Timber Structures and Prefabricated Concrete Composite Blocks as a Novel Development in Vertical Gardening

A modern, environmentally friendly urban lifestyle requires paying attention to landscaping and green areas. The scarcity of free land in cities and the high price of land require the combination of greenery with buildings—both vertically and horizontally. The developed green technology for construction brings together computer numerical control (CNC) processing of supporting structures and prefabricated solid planting blocks made of concrete composite. The timber structures are fixed together using traditional carpentry joints. The details, which will be manufactured in the factory using CNC processing at a controlled temperature and humidity corresponding to indoor conditions, can be easily assembled on the construction site. The high bending strength but good elasticity and connections of carpentry joints endow the structure with good properties in a non-controllable environment. By combining CNC-processed wooden structures with concrete technology as substrate composites, labor-intensive manual work in landscaping and gardening will be reduced in the future. The novel material-hardening substrate composite material uses only the residues as the raw materials