From genetics to ecology, Biology Topics cover a vast array of life sciences.
Why do Plants Grow ? and What are Crops and
Examples of Crops ?
All the living organisms like man, animals and plants need food for their growth and survival. The green plants can synthesise their food by the process of photosynthesis by using inorganic substances like carbon dioxide gas and water in the presence of sunlight energy. Man and other animals cannot make food by photosynthesis from carbon dioxide gas and water by using sunlight energy.
They need readymade organic food nutrients like carbohydrates, fats, and proteins, etc., for their growth and development. Man obtains his food from plants as well as animals. In other words, man has to grow plants and rear animals (bring up animals) to meet his requirements of food.
Many types of plants are grown on a large scale in vast fields because the food grains produced by them are consumed in large amounts. Wheat and rice are two common examples. These are called food grains. In addition to food grains, pulses, vegetables and fruits are also grown on a large scale because they are an important part of our food.
The animals such as cow and buffalo are reared to obtain milk whereas goat, fish and hen are reared to get meat and eggs. In this Chapter, we will study the different practices of obtaining food from both, plants as well as animals. Before we go further, we should know the meaning of the word crop’. This is discussed below.
When the same kind of plants are grown in the fields on a large scale to obtain foods like cereals (wheat, rice, maize), pulses, vegetables and fruits, etc., it is called a crop. For example, a crop of wheat means that all the plants grown in the fields are that of wheat (see Figure). A crop is called fasavin Hindi. Crops are grown in the soil in the fields by farmers (kissan).
Some of the examples of crops are given below:
- Cereal crops (Grain crops) : Wheat, Paddy (Rice), Maize, Millet (Bajra, Jawar), Barley
- Pulses : Gram (Ghana), Peas, Beans
- Oil seeds : Mustard, Groundnut, Sunflower
- Vegetables : Tomato, Cabbage, Spinach
- Fruits : Banana, Grapes, Guava, Mango, Orange, Apple
Types of Crops
Different crops grow well in different seasons of the year. For example, a crop may grow well in rainy season during summer but it may not grow well in winter season. Similarly, another crop may grow well in winter season but not in rainy season. Based on the seasons (in which they grow well), all the crops are categorised into two main groups:
- Kharif crops, and
- Rabi crops.
The crops which are sown in the rainy season are called kharif crops. The rainy season in India is generally from June to September. The sowing for kharif crops starts in June-July at the beginning of south-west monsoon because these crops (particularly paddy) need substantial amount of water. The kharif crops are harvested at the end of monsoon season during September (or October).
Some of the examples of kharif crops are : Paddy, Maize, Millet, Soyabean, Groundnut and Cotton. The kharif crops are sometimes also called ‘summer crops’. Please note that ‘paddy’ is ‘rice still in the husk’. So, paddy crop gives us rice. In other words, paddy is rice crop.
Paddy is grown only in the rainy season because it requires a lot of water. Paddy cannot be grown in the winter season because water available in winter is much less. On the other hand, if wheat is sown in the kharif season, it will not grow well. This is because wheat plants cannot tolerate too much water of the rainy season.
The crops grown in the winter season are called rabi crops. The time period of rabi crops is generally from October to March. The sowing for rabi crops begins at the beginning of winter (October-November) and the crops are harvested by March (or April). Some of the examples of rabi crops are : Wheat, Gram (Chana), Peas, Mustard, and Linseed.
The people who have no permanent homes and continuously move from one place to another are called ‘nomads’ (or wanderers). Till about 10000 B.C., people were nomadic. They were continuously moving (or wandering) in groups from place to place in search of food and shelter.
These nomadic people ate raw fruits and vegetables found in nature and started hunting animals for food. Later, they settled near the sources of water such as rivers and cultivated land to produce wheat, paddy (rice) and other food crops.
This is how agriculture was born. The growing of plants (or crops) in the fields for obtaining food (like wheat, rice, etc.) is called agriculture. Agriculture is called ‘khetibari’ or ‘krishi’ in Hindi. We will now describe the various agricultural practices.