The question asks for the definition of 'manure' in the context of agricultural science, specifically referencing NCERT Class 9. We need to identify the option that accurately describes manure based on its composition and function.
Correct Option: C) Manure is a natural substance prepared by decomposition of animal excreta and plant waste that enriches the soil with organic matter and nutrients
This definition accurately captures the essence of manure. It is organic, natural, and improves soil fertility by adding organic matter and essential nutrients.
The question asks to identify the classification of manure based on biological material used, as per NCERT Class 9. This requires knowledge of the specific categories of manure discussed in the NCERT textbook for that grade level.
Correct Option: D) Compost, Vermicompost and Green manure
This option correctly lists the three types of manure classified based on the biological material used and their preparation methods, as described in NCERT Class 9 Science textbooks.
The question asks for the definition and preparation method of compost. We need to identify the option that accurately describes compost as an organic manure and its biological preparation process.
D) Compost is organic manure prepared by decomposing farm waste materials (livestock excreta, vegetable waste, animal refuse, domestic waste, sewage, straw, weeds) in pits — the process is called composting. This option accurately describes compost as an organic fertilizer derived from the biological decomposition of organic waste materials, and correctly identifies the process as composting.
The question asks to identify the organisms used in vermicompost preparation and the name of the process. This requires knowledge of common composting methods and the specific biological agents involved.
A) Redworms (earthworms) are used; the process is called vermicomposting. This option correctly identifies both the organisms (redworms/earthworms) and the process (vermicomposting).
The question asks why vermicompost is considered superior to ordinary compost. We need to evaluate each option based on the known characteristics and benefits of vermicompost compared to traditional composting methods.
D) Vermicompost is richer in nutrients, has a better texture, contains beneficial microorganisms, and is produced faster than ordinary pit composting. This option accurately describes the advantages of vermicompost. Worms break down organic matter more thoroughly, increasing nutrient availability (e.g., nitrogen, phosphorus, potassium). The castings (worm excreta) improve soil structure, leading to a finer, more uniform texture. Vermicompost is teeming with beneficial microbes that enhance soil health and plant growth. Furthermore, the vermicomposting process is generally much faster than traditional pit composting.
The question asks to define 'green manure' and describe its preparation. We need to evaluate each option based on the standard agricultural definition and practice of green manuring.
C) Green manure is prepared by growing green plants (like sun hemp/sunn hemp or guar) in the field and then ploughing them into the soil before sowing crop seeds, so they decompose in situ. This is the correct definition and method for preparing green manure. The decomposition of these plants enriches the soil with organic matter and nutrients, particularly nitrogen if legumes are used, which fix atmospheric nitrogen.