Question

Which plant is used for green manuring in India?

• A. Wheat
• B. Sunhemp
• C. Cotton
• D. Rice

Hint:

Look for the fast growing legume whose whole green plant is ploughed back into the soil.

Answer 1

The Correct Option is B

Step 1: Understanding the Question.
Green manuring means growing a fast growing plant and then ploughing it directly into the soil while it is still green, to add organic matter and nutrients before the main crop is sown. The question asks which plant is grown for this purpose in India.

Step 2: Key Fact.
Sunhemp (Crotalaria juncea) is one of the most common green manure crops grown in India. It is a legume, so its roots carry nitrogen fixing bacteria in small nodules. These bacteria convert nitrogen gas from the air into a form the soil can use. Sunhemp grows fast and produces a large amount of soft green mass in a short time, which is why farmers plough it into the field a few weeks after sowing, well before it flowers and hardens.

Step 3: Detailed Explanation of Other Options.
Wheat, option (A), is a cereal crop grown for its grain. Farmers harvest and sell or eat the grain, they do not plough young wheat plants back into the soil as manure. Cotton, option (C), is a fiber crop grown for the fiber around its seeds and is harvested for that fiber, not used as green manure. Rice, option (D), is also a staple cereal grown for grain. Like wheat, rice is a food crop and is not grown to be turned back into the soil while green.

Step 4: Final Answer.
Sunhemp is grown specifically as a quick, nitrogen rich green manure crop in Indian farming.
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