Life cycle assessment of biochar and cattle manure application in sugar beet cultivation – Insights into root yields, white sugar quality, environmental aspects in field and factory phases

Sugar beet (Beta vulgaris L.) is a well-known sugar crop essential for supplying the global demand for sugar. Examining how different farming techniques affect the environment may help produce a high-quality crop with the least negative environmental effects. To this, the life cycle assessment (LCA) of biochar (B) and cattle manure (CM) applications at three different rates (5, 10, and 15 tons ha⁻¹) compared with conventional chemical fertilization (CH) in the autumn and spring sugar beet crops has been studied. The system boundaries for LCA analysis were set from the cradle to the sugar factory gate. Based on the results, the highest amounts of root yield were obtained under CM10 and CM15 treatments with 24.5% and 23.2% increase in autumn cultivation and 34.8%, and 33.9% increase in spring cultivation, compared to CH. However, CM15 resulted in significantly lower sugar content (10.9%) than B5 (17%). Also, B utilization significantly reduced molasses content in sugar beet rather than CM in both cultivation periods. Further, biochar treatments (B5, B10, B15) significantly increased the white sugar yield in both cultivation times by 43.7%, 39.2%, and 36.1%, on average. Generally, the highest and the lowest global warming potential (GWP) were obtained from CM15 and B15 with 638.5 and 437.2 CO₂-eq ton⁻¹ root/sugar yields, respectively. These findings validate the hypothesis that using biochar in sugar beet production could reduce greenhouse gas emissions while increasing the amount of white sugar produced.