Topic: pH value. Why is pH value important to a farmer? What is happening to the tree? Is it merely because of pH? Yes, you are right. pH is the measure of acidity or basicity of
a substance. It is expressed by positive numbers ranging from 0 to 14 where 7 indicates a neutral value. Neither acidic nor basic. When the pH value of a substance is below 7. It is termed as acidic and when it is above 7, it is termed as basic. The pH value of ideal soil is usually close
to neutral. It ranges from about 6.5 to 7.5. If we don’t maintain this pH, growth of most of the plants is adversely affected. Are you shocked? Did the white marble just turn yellowish brown due to acid rain? Yes, you are right. The pH of rainwater is about 5.6. This means that rainwater is slightly acidic. This slightly acidic nature of rainwater does not really cause any damage. But, in last few years, many harmful substances are being released into the atmosphere. Addition of these substances drops the pH of rainwater. In certain cities, the proportion of these
harmful substances is so high in the atmosphere. That it drops the pH of rainwater to a much lower level making it strongly acidic. When this strongly acidic rainwater falls
down, it is termed as acid rain. This acid rain not only discolors white marbles, but also harms human beings and animals in several ways. Did the plant just turn yellow? Why do you think this happened? The plant turned yellow due to increase in
pH value of the soil. A pigment named chlorophyll gives a plant its green color. The plant prepares chlorophyll with the help of iron. When the plant absorbs water from soil. It also takes in iron present in that soil and prepares chlorophyll. However, when the pH of soil increases, that is, when it becomes more basic, the availability of iron decreases. As a result, the plant does not get the required amount of iron to make chlorophyll and hence, it turns yellow. Also, besides the availability of iron. pH value of soil also affects the level of toxic substances, growth of bacteria and roots, etc. Thus, when a farmer has to grow any crop, he has to know the value of pH of his soil for a good yield. Otherwise, his crop will face undesirable
consequences. Ultimately, he may suffer a great loss.