Application of microalgae in cauliflower fertilisation

Abstract

In a circular bioeconomy, balancing inorganic fertilisers and microalgae supplementation is important for ensuring sustainable agriculture. This study aimed to evaluate the fertilising effects of live microalgae (mostly Chlorella vulgaris and a mixture of Chlorophyceae and Trebouxiophyceae) on cauliflower (Brassica oleracea L. subsp. botrytis) plant morphology, yield, and quality of cauliflower heads. Microalgae fertilisation effects were analysed by employing an experimental factorial design with two factors: inorganic fertiliser and microalgae, each at high and low dosage levels, and the results revealed higher plant height, wider stem diameter, and lower stem slenderness in high-dose combinations than those in other combinations. In addition, an increase in nitrate, calcium, potassium, and sodium content was observed in the sap of cauliflower leaves in high-dose combinations compared to those in low-dose combinations. The high-dose combination also increased the yield, number of commercial heads, weight of the heads, and number of curds per head of cauliflower. Overall, the study demonstrates that increasing the dose of inorganic fertilisers and microalgae significantly increases nutrient concentration in the sap, which translates into a larger plant, an increase in the number of leaves and yield, and an improvement in the quality of cauliflower heads. These findings underscore the necessity for further research to ascertain the optimal combination of inorganic fertilisers and microalgae to maximise crop yield and cauliflower head quality.