Restoring soils with organic soil amendments; A case study in Geitasandur, South Iceland.

• Main Author: Parnika Gupta 1993-
• Other Authors: Háskóli Íslands
• Format: Master Thesis
• Language: English
• Published: 2023
• Subjects: Umhverfis- og auðlindafræði; Jarðvegsrannsóknir; Iceland
• Online Access: http://hdl.handle.net/1946/45985

Soil is a limited global resource, and it is threatened by anthropogenic activities like erosion, infertility from excessive use of chemical fertilizers and desertification that is amplified by climate change. This research analysed soils and subsequent data from a revegetation study by the Soil Conservation Service of Iceland and aimed to address the effects of various soil amendments on soil properties and vegetation cover. Four organic soil amendments including municipal waste, bokashi, chicken manure, and bonemeal were compared to two application rates of chemical fertilizers and a control. Methods involved i) analysis of soil samples for pH, soil organic matter, C/N, and available carbon; ii) vegetation surveys measuring vegetation height and vegetation cover in 2021 and 2022; and iii) a tea-bag index study to investigate decomposition rates in soil. Soil pH was significantly higher in bonemeal plots than in plots where higher dose of chemical fertilizer was applied. For 2021, grass cover and vegetation height were significantly greater in chemical fertilizer plots than the control. Two years post application (2022), vegetation cover was significantly higher for plots with chemical fertilizer, bonemeal, and chicken manure than the control. Decomposition rates did not vary among the treatments, but the litter stabilisation factor was significantly higher for chicken manure than in the control and bokashi plots. Organic soil amendments like chicken manure and bonemeal can be alternatives to chemical fertilizers. This study is an important step for reducing waste and achieving circular economy by restoring soils using locally sourced organic soil amendments. Jarðvegur er takmörkuð auðlind sem er ógnað með margvíslegum hætti s.s. rofi, ófrjósemi vegna óhóflegrar notkunar á tilbúnum áburði og eyðimerkurmyndun tengd loftslagsbreytingum. Í rannsókninni sem hér er lýst eru skoðuð áhrif mismunandi gerða lífræns áburðar á framvindu gróðurs og jarðvegs, en hún er hluti af uppgræðslutilraunum á vegum Landgræðslunnar. ...