CBSE Class 8 Science Chapter 1: Crop Production and Management NCERT Solutions

(a) The same kind of plants grown and cultivated on a large scale at a place is called a crop. This means a large area is dedicated to growing a single type of plant for food or other purposes.

(b) The first step before growing crops is the preparation of the soil. This involves loosening and turning the soil to make it suitable for planting seeds.

(c) Damaged seeds would typically float on top of water. Healthy seeds are usually denser and sink, while damaged or lighter seeds float.

(d) For growing a crop, sufficient sunlight and water and nutrients from the soil are essential. Plants need these elements for photosynthesis and overall growth.

Here is the correct matching of items from Column A to Column B:

• (e) Paddy and maize matches with (i) Kharif crops. These crops are grown during the rainy season.
• (d) Wheat, gram, pea matches with (ii) Rabi crops. These crops are typically grown in the winter season.
• (b) Urea and super phosphate matches with (iii) Chemical fertilisers. These are synthetically produced substances that provide essential nutrients to plants.
• (c) Animal excreta, cow dung, urine and plant waste matches with (iv) Organic manure. These materials are decomposed to form manure, which improves soil fertility.
• (a) Food for cattle is a general term that can refer to crops like fodder, which are grown specifically for feeding livestock. While not directly matched to a numbered option in the provided list, it relates to agricultural produce.

Here are two examples for each type of crop:

(a) Kharif crops are typically grown during the monsoon season (June to September). Examples include:

• Paddy (Rice)
• Maize (Corn)

(b) Rabi crops are typically grown during the winter season (October to March). Examples include:

• Wheat
• Gram (Chickpea)

(a) Preparation of soil: This is the very first and a critical step before planting any crop. The soil needs to be turned and loosened. This process allows the plant roots to easily penetrate deeper into the soil, facilitating better absorption of water and nutrients. Loosening the soil also helps beneficial organisms like earthworms and microbes to thrive, which in turn add humus to the soil. Furthermore, turning the soil brings the nutrient-rich soil from deeper layers to the top, making these nutrients available for the plants to use.

(b) Sowing: Sowing is a fundamental part of growing crops. Before sowing, it is important to select good quality seeds. These seeds should be clean, healthy, and of a superior variety to ensure a good yield. Sowing can be done manually by scattering the seeds or using a tool called a seed drill, which ensures seeds are planted at a uniform depth and spacing.

(c) Weeding: Weeds are unwanted plants that grow alongside the main crop, competing with it for resources like water, nutrients, and sunlight. The process of removing these unwanted plants is called weeding. Weeding can be done manually using tools such as a 'khurpi', or it can be done chemically by spraying specific herbicides called weedicides (like 2, 4 – D). These chemicals are designed to kill the weeds without harming the crop.

(d) Threshing: Threshing is the agricultural process used to separate the edible grain from the inedible chaff and straw after the crop has been harvested. This is often done using machinery. A 'combine' harvester is a machine that can perform both harvesting and threshing simultaneously, efficiently separating the grains from the rest of the plant material.