Effects of Soil on Water

605 Words3 Pages
Did you know that soils can be alkaline, neutral, or acidic? Most plants grow best in soil near neutral pH, but some plants prefer slightly acidic and others slightly alkaline soil. What is the pH of the soil in your garden? What happens to the pH of water that comes in contact with soil? Here's how to find out. Objective The objective of this experiment is to measure how contact with different types of soil changes the pH of water. Introduction The level of acidity or alkalinity of a soil is one indicator of the soil's health and suitability for growing particular types of plants. Acidity and alkalinity are measured with a logarithmic scale called pH. pH is the negative logarithm of the hydrogen ion concentration: pH = −log [H+] . What this equation means is for each 1-unit change in pH, the hydrogen ion concentration changes ten-fold. Pure water has a neutral pH of 7. pH values lower than 7 are acidic, and pH values higher than 7 are alkaline (basic). The table below has examples of substances with different pH values…Most plants prefer soil that is near neutral pH. There are particular varieties (strawberries, azaleas and rhododendrons, for example) that prefer acidic soil. Soil pH also influences how readily available many soil nutrients are to plants. • In this project, you will measure pH values of different types of soils, and you will see how the soil affects the pH of water that comes in contact with it. When soil and water meet, their acidity levels interact and combine to influence both. Ultimately, the water drains away and the soil assumes a slightly different acidic content. The acidity of the soil is very important, since how acidic or alkaline a soil is governs what kind of plants can grow there and how easily roots can extract the necessary nutrients to survive. In both water and soil, acidity is measured according to the pH scale, a
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