The pH of the soil is important because it is the roots’ living environment. Once you know the soil’s pH, you have an idea of what the irrigation water’s pH should be.
The plants do best and plant nutrients are most available when the soil pH is between 6-6.5, slightly acid. If the soil has a higher pH than that, the irrigation water’s pH should be lowered to help the soil or planting mix pH adjust. If the soil has a lower pH, the irrigation water’s pH should be adjusted to counteract the high acidity.
You can get an idea of what your soil needs by checking the pH of the drain water. Its pH should be within the correct pH range. Plants that are grown in a nutrient that is too acidic grow slowly and are stunted. When the pH is too high, the plants also grow slowly and turn an unusual light green color.
The pH of irrigation water, drain water and soil can all be tested with a pH tester that is readily available at garden stores, and ranges in price between $50-$100.
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