Larsen, et al (2024) Organic amendments improved soil properties and native plants’ performance in an Australian degraded land. Soil Research.

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Land degradation is an escalating environmental issue that adversely affects ecosystems and human health. In addressing this challenge, a recent study in Australia explored the impact of organic soil amendments on enhancing the physicochemical properties of degraded soils and the growth of native plant species. Conducted in a glasshouse setting, the research examined the effects of compost (CO), biochar (BC), and a compost-biochar mix (COBC) on three indigenous plant species: Eucalyptus tereticornis (EU), Acacia leiocalyx (AC), and Banksia integrifolia (BA).

The study revealed several key findings. All organic amendments improved soil quality by increasing levels of dissolved organic carbon and microbial biomass carbon. Specifically, the COBC mix was most effective in enhancing nutrient retention and reducing carbon dioxide emissions compared to compost alone. Interestingly, the biochar amendment showed carbon dioxide emissions comparable to the control (untreated soil), indicating minimal immediate impact on emission reduction.

Among the tested species, Acacia leiocalyx, a leguminous plant, exhibited superior biomass production, regardless of the soil treatment. This highlights its potential resilience and effectiveness in soil rehabilitation strategies. The Eucalyptus treatments with the COBC mix showed the most significant increase in biomass, suggesting that combining compost and biochar could offer the best results for this species.

Although all amendments led to general improvements in soil and plant health, the benefits from biochar alone were limited in this short-term study, suggesting that its long-term advantages may require further exploration. This research underscores the need for continued investigation into how different soil amendments affect various soil types and native vegetation, paving the way for more informed ecological restoration practices.

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