Question

If a test of the farmer's soil shows it has a pH of 8.0, what nutrients are likely to be less available to the plant? a) Nitrogen and phosphorus b) Potassium and calcium c) Iron and manganese d) Sulfur and boron

Answer 1

In soil with a pH level of 8.0, micronutrients like iron and manganese become less available for plant absorption. This is because these nutrients' solubility and, therefore, their availability, reduces in alkaline conditions. Nitrogen, potassium, and phosphorus are typically more available varying pH conditions.

Step-by-step explanation:

If a farmer's soil test indicates a pH of 8.0, the soil is considered slightly alkaline. In slightly alkaline conditions (pH above 7.0), certain essential nutrients for plant growth are less available. These are mainly micronutrients such as iron and manganese, as well as other micronutrients like zinc, copper, and boron.

These precipitation reactions occur in higher pH soils, reducing the solubility of these nutrients, and hence, their availability for plant absorption. Thus, in an alkaline soil with a pH of 8.0, these specific micronutrients will be less available for plant uptake.

Nitrogen, potassium, and phosphorus are considered macronutrients, and their absorption is less affected by soil pH than micronutrients. Therefore, these macronutrients are typically more available to plants in varying pH conditions compared to micronutrients like iron and manganese.

Learn more about Nutrient availability in different soil pH