*3.2.2 Effect of vinegar residue on blueberry nutrient uptake*

The application of vinegar residue had no significant effect on the absorption of phosphorus in blueberry leaves, roots, and fruits (**Table 2**), and there was also no significant effect on the absorption of nitrogen in blueberry leaves and fruits (**Table 2**). In terms of total nitrogen content in roots, vinegar residue significantly promoted the total nitrogen content in roots. Total nitrogen in roots of VR1 and VR2 treatment increased by 18.86 and 24.06%, respectively, compared with CK.
