Ans. When plants of the same kind are grown and cultivated at one place on a large scale, it is called a crop. For example, crop of wheat means that all the plants grown in a field are that of wheat.
Ans. This tool sows the seeds uniformly at proper distances and depths. It ensures that seeds get covered by the soil after sowing. This prevents damage caused by birds. Sowing by using a seed drill saves time and labour.
Ans. The water available in wells, lakes and canals is lifted up by different methods in different regions, for taking it to the fields. Cattle or human labour is used in these methods. So these methods are cheaper, but less efficient.
Ans. Take a beaker and fill half of it with water. Put a handful of wheat seeds and stir well. Wait for some time. Are there seeds which float on water? Seeds that float on water are the damaged ones. Damaged seeds become hollow and are thus lighter. Therefore, they float on water.
Ans. Advantages of drip system of irrigation are:
i. It is the best technique for watering fruit plants, gardens and trees.
ii. The system provides water to plants drop by drop. Water is not wasted at all.
iii. It is a boon in regions where availability of water is poor.
Ans. Since only a few centimetres of the top layer of soil supports plant growth, turning and loosening of soil brings the nutrient-rich soil to the top so that plants can use these nutrients. Thus, turning and loosening of soil is very important for cultivation of crops.
Ans. Continuous plantation of crops in a field makes the soil deficient in certain nutrients such as nitrogen, phosphorus, potassium, etc. These nutrients are essential for the growth of plants. As such soil does not get time to replenish the lost nutrients, the crop yield decreases automatically.
Ans. The various traditional ways are:
i. moat (pulley-system)
ii. chain pump
iii. dhekli, and
iv. rahat (Lever system)
Ans. The removal of weeds is called weeding. Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light. Thus, they affect the growth of the crop. Some weeds interfere even in harvesting and may be poisonous for animals and human beings.
Ans. Manure is an organic substance obtained from the decomposition of plant or animal wastes. Farmers dump plant and animal waste in pits at open places and allow it to decompose. The decomposition is caused by some microorganisms. The decomposed matter is used as organic manure.
Ans. Water is essential because germination of seeds does not take place under dry conditions. Nutrients dissolved in water get transported to each part of the plant. Water also protects the crop from both frost and hot air currents. To maintain the moisture of the soil for healthy crop growth, fields have to be watered regularly.
Ans. Following are the characteristics of a good quality seed:
i. It should be clean.
ii. It should be healthy and of good variety.
iii. It should have high yield.
iv. It should be disease resistant.