The correct option is (c) 1 and 3 only.
Explanation
Silos are specialized structures used in agriculture for the bulk storage of grain and fermented feed (silage). They are an essential component of post-harvest management, designed to protect harvested crops from biotic and abiotic factors.
Statement-wise Analysis
- Statement 1 is Correct: Silos are specifically designed for the large-scale, bulk storage of food grains such as wheat, maize, and rice. They allow for the efficient handling and preservation of large quantities of produce.
- Statement 2 is Incorrect: Silos are closed and often airtight structures, not open ones. Their primary function is to protect grains from pests (such as rats and insects), moisture, and fungal growth. Open storage would defeat the purpose of long-term preservation.
- Statement 3 is Correct: Structurally, silos are typically tall, cylindrical towers constructed from materials like galvanized metal or reinforced concrete. This vertical design minimizes the ground footprint while maximizing storage volume and facilitating gravity-based grain discharge.
Key Takeaway
Silos are tall, closed metallic or concrete structures used for the bulk storage of grains, specifically designed to protect produce from pests, rodents, and moisture, unlike open storage methods.