Question

Which of the following does not cause desertification?

• A. Poor irrigation practices
• B. Over cultivation
• C. Deforestation
• D. Restricted grazing

Answer 1

The correct option is D Restricted grazing

Desertification is a process which turns productive land into a non-productive desert as a result of poor land management.

Some of the causes of desertification are as follows :

• Over cultivation - It is the practice of cultivating land to an excessive degree in the growing of crops so that soil quality is degraded and productivity is reduced. Using the land continuously results in the depletion of nutrients and makes it infertile and a desert.
• Unrestricted grazing - Continuous grazing by the herbivores can result in deforestation.
• Deforestation - It is the cutting down of trees due to anthropogenic action (humans) or natural causes. This can affect the soil properties. The fertile top layer is removed which exposes the lower layers which have less humus (dark, organic material that forms in soil when plant and animal matter decays) and are less fertile. In the absence of trees, the soil becomes exposed and this leads to soil erosion. The deforested areas experience extremely arid climates leading to desertification and droughts.
• Poor irrigation practices - It involves the construction of irrigation systems that cannot provide the necessary soil-water-nutrient environment for optimum crop growth. Irrigation with saline water also adversely affects crop growth and productivity. Seepage from canals, poor drainage and intrusion of seawater also leads to salinity. All these increase the chances of desertification.

If restricted grazing is being followed then the plants or grasses will be available to hold the soil and moisture. The litter generated by the plant is decomposed by decomposers further adding nutrients and fertility to soil. Hence option d is correct.