PH
pH is a logarithmic measure of how acidic or alkaline a solution is, with 7 neutral under ordinary reference conditions. In mango growing, soil or potting-medium pH influences nutrient availability and helps explain problems such as iron deficiency in alkaline conditions. It does not measure how much fertilizer is present. Use an appropriate soil test and consider irrigation-water chemistry before adding acidifying or liming materials; changing pH blindly can create a different nutrient imbalance.