URI | http://purl.tuc.gr/dl/dias/293F9CCB-8F70-4CB4-B475-454801361993 | - |
Identifier | https://doi.org/10.26233/heallink.tuc.105071 | - |
Language | en | - |
Extent | 92 pages | en |
Title | Seasonal variation of enzyme activity in fields under different management practices | en |
Creator | Frantzeskou Maria | en |
Creator | Φραντζεσκου Μαρια | el |
Contributor [Thesis Supervisor] | Paranychianakis Nikolaos | en |
Contributor [Thesis Supervisor] | Παρανυχιανακης Νικολαος | el |
Contributor [Committee Member] | Karatzas Georgios | en |
Contributor [Committee Member] | Καρατζας Γεωργιος | el |
Contributor [Committee Member] | Nikolaidis Nikolaos | en |
Contributor [Committee Member] | Νικολαιδης Νικολαος | el |
Publisher | Πολυτεχνείο Κρήτης | el |
Publisher | Technical University of Crete | en |
Academic Unit | Technical University of Crete::School of Chemical and Environmental Engineering | en |
Academic Unit | Πολυτεχνείο Κρήτης::Σχολή Χημικών Μηχανικών και Μηχανικών Περιβάλλοντος | el |
Content Summary | The intensified conventional agriculture practices have as an effect the deterioration of soil health, threatening the resilience of agroecosystems to climate change. The adverse effects of climate change on soil health are especially alarming in arid and semi-arid regions like the Mediterranean basin, where inputs of organic matter are already low due to limitations imposed by high temperature and water scarcity. Decline in soil organic matter, along with decrease of fertility and biodiversity loss are among the impacts on soil health. Soil organic matter is inextricably linked with soil health and fertility, serving as the main energy source for soil microbiota and playing a crucial role in nutrient cycling and availability in agricultural ecosystems. While the conversion of agroecosystems from conventional to conservation agriculture practices to restore soil organic matter and soil health has been applied globally, the effect and benefits of such conversions in semi-arid environments remain unclear.
The objective of this thesis was to improve our understanding on the effects of seasonal and spatial variation on the drivers regulating soil organic matter turnover in agroecosystems in semi-arid landscapes. To achieve that, soil chemical and biological parameters in four experimental olive orchards subjected to conventional and conservation management practices were sampled. Soil extracellular enzyme activities serve as a valuable indicator to get insights of soil health, since they have the potential to yield insightful information about the responses of microorganisms to its abiotic environmental and their significance for soil processes. The role of microbial communities in agriculture is vital, being primer decomposers of SOM to meet energy demands and regulate nutrient biogeochemical cycles. Another important indicator of soil health is microbial biomass, being the living component of soil organic matter.
The experimental design of this thesis was divided into field study and lab experiments under controlled conditions. The field study included temperature monitoring at the four olive orchards subjected to different management practices, for three consecutive seasons. Lab experiments included potential soil enzyme activity, microbial biomass carbon and soil organic carbon using soil seasonally sampled from the olive orchards. The potential soil enzyme activities of β-glucosidase, β-xylosidase, phosphatase and β-N-acetyl-glucosaminidase were measured fluorometrically, while soil microbial biomass carbon was determined using the chloroform fumigation-direct extraction method with sieved field-moist soil. For the determination of soil organic carbon, dry soil samples were analysed using the dry combustion method.
Understanding the temperature sensitivity of SOM decomposition in semi-arid soils, like in the Mediterranean basin, would help predict their response to climate change. The findings of this dissertation reveal positive feedback with agronomic management change from conventional to conservation treatment. The results indicate that conservation practices with added organic matter have higher SOC, benefitting the soil C dynamics and biological activity. While enzyme activity is a sensitive indicator of land management-change, it showed higher sensitivity to seasonal variability. | en |
Type of Item | Μεταπτυχιακή Διατριβή | el |
Type of Item | Master Thesis | en |
License | http://creativecommons.org/licenses/by/4.0/ | en |
Date of Item | 2025-10-20 | - |
Date of Publication | 2025 | - |
Subject | Soil organic carbon | en |
Subject | Soil health | en |
Subject | Extracellular enzyme activity | en |
Bibliographic Citation | Maria Frantzeskou, "Seasonal variation of enzyme activity in fields under different management practices", Master Thesis, School of Chemical and Environmental Engineering, Technical University of Crete, Chania, Greece, 2025 | en |