Question

How do soils become fertile?

Answer 1

Hint: Soil fertility refers to a soil's ability to support agricultural plant development, i.e., to provide plant habitat and produce high-quality yields over time. It is the ability to provide necessary plant nutrients and water in sufficient quantities and proportions for plant growth and reproduction; and the absence of harmful substances that could stifle plant growth.

Complete answer:
Crops, like humans, need nutrients and the soil which has an abundance of nutrients that are required for good growth of the plant is known as fertile soil. Following are a few of the points which explain how soil can become fertile and how this fertility can be maintained.

Fertile soil will contain all of the major nutrients needed for basic plant nutrition (such as nitrogen, phosphorus, and potassium), as well as other nutrients in smaller amounts (e.g., calcium, magnesium, sulfur, iron, zinc, copper, boron, molybdenum, nickel). Adding an adequate amount of such nutrients through organic manure and chemical fertilizers can make the soil fertile.

Fertile soil will usually contain some organic matter, which increases soil structure, moisture retention, and nutrient retention, as well as a pH of 6 to 7. Soil fertility can be increased further by using cover crops that add organic matter to the soil, improving soil structure and promoting a stable, fertile soil; or by using green manure or growing legumes that fix nitrogen from the air through the biological nitrogen fixation process.

 Micro-dose fertiliser applications to replenish losses due to plant absorption and other processes, and enhanced water and nutrient application to minimise losses due to leaching below the crop rooting zone. Further soil fertility can be managed by some nuclear and isotopic techniques.

Note:
- Natural processes take 2,000 years to create 10 centimeters of fertile soil from bedrock. About 24 billion tons of topsoil are lost each year due to agriculture and erosion, which equates to over 3 tons per individual.
- A handful of soil contains more microorganisms than there are humans on the planet.
- According to the Food and Agriculture Organization, healthy soil with high organic matter can store 20 times its weight in water. Drought resistance depends on the ability to retain water.