Soil algae for combating soil degradation – greenhouse experiment with different soil amendments

Abstract

Context Our research contributes to the knowledge of using soil algae to combat soil degradation. Aims We tested green algae (Klebsormidium flaccidum) and a field soil algae community in a 3-month greenhouse experiment and studied their performance on two substrates: (1) sand from the Ordos Desert; and (2) artificial desert sand (washed sand). Methods A rapid fluorescence microscopy-Image J method was developed to estimate the abundance of algae. We studied the effects of four soil amendments (biochar, clay, organic matter, geohumus) on the development of green algae, field algae and biological soil crusts. Key results The field algae preferred washed sand. All amendments had a positive effect on the abundance of K. flaccidum and field algae. Biological soil crusts were generally lower in control and organic matter treatments, but relatively higher in biochar and clay treatments. No relationship between algal abundance and soil crust stability was found in this short-term experiment. Conclusions Our rapid fluorescence microscopy-Image J method quantitatively estimated algal abundance aunder different conditions, providing an indirect indicator of their growth status. Implications This method can be used to make recommendations on soil amendments and their effect on algal growth studies.