1. What do we get from cereals, pulses, fruits, and vegetables?
Ans: Cereals are a rich source of carbohydrates, which provide the body with energy.
Pulses are a great source of protein, essential for growth, development, and repair of tissues.
Fruits and vegetables are packed with minerals, vitamins, carbohydrates, proteins, and fats, contributing to overall health and development by supporting various bodily functions.
2. How do biotic and abiotic factors affect crop production?
Ans: Two major factors that affect crop production are:
Biotic factors: These include living organisms like insects, rodents, pests, and pathogens that can spread diseases and damage crops, reducing their yield.
Abiotic factors: These are non-living elements such as humidity, temperature, moisture, wind, rain, and floods that can damage crops or make conditions unfavorable for their growth, affecting the overall crop production.
3. What are the desirable agronomic characteristics for crop improvement?
Ans: The essential agronomic features required for crop improvement are:
Profuse branching and tallness in fodder crops to maximize yield and ensure better forage production.
Dwarfness in cereals like wheat and rice to improve stability, prevent lodging (falling), and enhance harvest efficiency.
3. What are the desirable agronomic characteristics for crop improvement?
Ans: The essential agronomic features required for crop improvement are:
Profuse branching and tallness in fodder crops to maximize yield and ensure better forage production.
Dwarfness in cereals like wheat and rice to improve stability, prevent lodging (falling), and enhance harvest efficiency.
4. What are macro-nutrients, and why are they called macronutrients?
Ans: Macro-nutrients are the fundamental elements that are used by plants in more quantity. Macro-nutrients needed by the plants are
Macro-nutrients as the constituent of protoplasm.
Phosphorus, Nitrogen, and Sulphur are present in proteins.
Calcium exists in the cell wall.
Magnesium is a significant component of chlorophyll.
5. How do plants get nutrients?
Ans: Plants require 16 basic essential nutrients for growth. Carbon and oxygen are obtained from the air (through carbon dioxide) and water (through transpiration). The remaining nutrients, such as nitrogen, phosphorus, potassium, and others, are absorbed from the soil through the plant’s roots.
6.Compare the use of manure and fertilizers in maintaining soil fertility.
Ans:
Manure:
Manure improves soil quality by adding essential nutrients.
It provides extra organic matter (humus) to the soil, which increases water retention in sandy soils and improves drainage in clayey soils.
Manure helps reduce soil erosion by binding the soil particles.
It provides food for soil-friendly bacteria, promoting healthy soil ecosystems that aid in crop growth.
Fertilizers:
Fertilizers can make the soil dry and powdered, increasing the risk of soil erosion.
They decrease organic matter, reducing soil porosity, which affects the plant roots’ ability to access oxygen.
Fertilizers can alter the pH of the soil, making it either too acidic or too basic, which may harm plant growth.
7. Which of the following conditions will give the most benefits? Why?
(a) Farmers use high-quality seeds; do not adopt irrigation or use fertilisers.
(b) Farmers use ordinary seeds, adopt irrigation and use fertiliser.
(c) Farmers use quality seeds, adopt irrigation, use fertiliser and use crop protection measures.
Ans:
Option (c) will give the most benefits because the use of good quality seeds is not only sufficient until the soil is properly irrigated, enriched with fertilisers and protected from biotic factors.
8. Why should preventive measures and biological control methods be preferred for protecting crops?
Ans:
Over-exposure to chemicals leads to environmental problems; hence, biological methods are preferred for protecting crops from pathogens, insects and rodents, along with increasing production. Since chemicals are harmful to plants and also to the animals which feed on them, bio-pesticides are used as a safe way of crop protection.
9. What factors may be responsible for the losses of grains during storage?
Ans: The loss of grains during storage can be caused by both biotic and abiotic factors, such as:
Rodents: They may consume or damage the grains.
Pests: Insects like weevils and beetles can infest grains and reduce their quality.
Insects: Certain insects damage grains by feeding on them.
Fungi: Fungal growth can lead to mold and spoilage of the grains.
Bacteria: Bacterial infections can cause decay and make the grains unfit for consumption.
Sunlight: Exposure to direct sunlight can degrade the quality of grains and cause them to spoil.
Flood: Excess water from flooding can damage stored grains and promote microbial growth.
Rain: Rain can increase moisture content, leading to mold and spoilage.
Temperature: High temperatures can accelerate the deterioration of grains, causing them to spoil.
Moisture: High moisture content can lead to fungal growth and degradation of the grains.
10. Which method is commonly used for improving cattle breeds and why?
Ans: Cross-breeding is commonly used for improving cattle breeds. This method involves breeding two different but genetically superior cattle breeds to produce offspring with desirable traits from both parents. Cross-breeding results in improved qualities such as higher milk or meat production, better disease resistance, and enhanced adaptability to different climatic conditions. By carefully selecting the parent breeds, cross-breeding can improve productivity, health, and overall performance of the cattle.