CROP PRODUCTION AND MANAGEMENT: Class 8 Science NCERT Chapter 1 Note

We know that energy from the food is utilised by organisms for carrying out their various body functions, such as digestion, respiration and excretion. We get our food from plants, or animals, or both.

So that it needs to provide food for a large population— regular production, proper management and distribution is necessary.

1.1 Agricultural Practices

Crop: When plants of the same kind are 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.

In India two broad cropping patterns can be identified. These are:

1. Kharif 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. Paddy, maize, soyabean, groundnut and cotton are kharif crops.
2. Rabi Crops: The crops grown in the winter season (October to March) are called rabi crops. Examples of rabi crops are wheat, gram, pea, mustard and linseed.

Besides these, pulses and vegetables are grown during summer at many places.

1.2 Basic Practices of Crop Production

(i) Preparation of soil
(ii) Sowing
(iii) Adding manure and fertilisers
(iv) Irrigation
(v) Protecting from weeds
(vi) Harvesting
(vii) Storage

1.3 Preparation of soil

• The preparation of soil is the first step before growing a crop.
• One of the most important tasks in agriculture is to turn the soil and loosen it.
• This allows the roots to penetrate deep into the soil.
• The loose soil allows the roots to breathe easily even when they go deep into the soil.

• The loosened soil helps in the growth of earthworms and microbes present in the soil.
• These organisms are friends of the farmer since they further turn and loosen the soil and add humus to it.

Tilling or Ploughing: The process of loosening and turning of the soil is called tilling or ploughing.

Crumbs: The ploughed field may have big clumps of soil called crumbs.

• Sometimes, manure is added to the soil before tilling.
• This helps in proper mixing of manure with soil.
• The soil is moistened before sowing.

Agricultural Implements

Plough: This is being used since ancient times for tilling the soil, adding fertilisers to the crop, removing the weeds and turning the soil. This is made of wood and is drawn by a pair of bulls or other animals.

Hoe : It is a simple tool which is used for removing weeds and for loosening the soil. It has a long rod of wood or iron. A strong, broad and bent plate of iron is fixed to one of its ends works like a blade. It is pulled by animals.

Cultivator : Nowadays ploughing is done by tractor-driven cultivator. The use of cultivator saves labour and time.

1.4 Sowing

• Sowing is an important part of crop production.
• Before sowing, good quality, clean and healthy seeds of a good variety—are selected.
• Farmers prefer to use seeds which give high yield.

Selection of Seeds

Traditional tool : The tool used traditionally for sowing seeds is shaped like a funnel. The
seeds are filled into the funnel, passed down through two or three pipes having sharp ends. These ends pierce into the soil and place seeds there.

Seed drill : The seed drill is used for sowing with the help of tractors. This sows the seeds
uniformly at equal distance and depth. It ensures that seeds get covered by the soil after sowing. This protects seeds from being eaten by birds. Sowing by using a seed drill saves time and labour. Appropriate distance between the seeds is necessary to avoid overcrowding of plants. This allows plants to get sufficient sunlight, nutrients and water from the soil. At times a few plants may have to be removed to prevent overcrowding.

1.5 Adding manure and fertilisers

Manure and fertilisers: The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilisers.

Manuring: The continuous cultivation of crops makes the soil poor in nutrients. Therefore, farmers have to add manure to the fields to replenish the soil with nutrients. This process is called manuring.

• 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.

• Fertilisers are chemicals which are rich in a particular nutrient.
• Some examples of fertilisers are— urea, ammonium sulphate, super phosphate, potash, NPK (Nitrogen, Phosphorus, Potassium).

• The use of manure improves soil texture as well as its water retaining capacity.
• It replenishes the soil with nutrients.

• The method of replenishing the soil with nutrients is through crop rotation.
• This can be done by growing different crops alternately.
• The farmers in northern India used to grow legumes as fodder in one season and wheat in the next season.
• This helped in the replenishment of the soil with nitrogen.

Rhizobium bacteria present in the nodules of roots of leguminous plants. They fix atmospheric nitrogen.

Advantages of Manure:

• The organic manure is considered better than fertilisers.
• This is because l it enhances the water holding capacity of the soil.
• It makes the soil porous due to which exchange of gases becomes easy.
• It increases the number of friendly microbes.
• It improves the texture of the soil.

1.6 Irrigation

The supply of water to crops at regular intervals is called irrigation.

The time and frequency of irrigation varies from crop to crop, soil to soil and season
to season. In summer, the frequency of watering is higher.

Sources of irrigation : The sources of water for irrigation are— wells, tubewells, ponds, lakes, rivers, dams and canals.

The various traditional ways are:

• moat (pulley-system)
• chain pump
• dhekli, and
• rahat (Lever system)

Modern Methods of Irrigation

Sprinkler System

• This system is more useful on the uneven land where sufficient water is not available.
• The perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals.
• When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles.
• It gets sprinkled on the crop as if it is raining.
• Sprinkler is very useful for lawns, coffee plantation and several other crops.

Drip system

• In this system, the water falls drop by drop directly near the roots. So it is called drip system.
• It is the best tech nique for watering fruit plants, gardens and trees.
• Inthis process water is not wasted at all.
• It is a boon in regions where availability of water is poor.

1.7 Protecting from weeds

Weeds: In a field many other undesirable plants may grow naturally along with the crop. These undesirable plants are called weeds.

Weeding: The removal of weeds is called weeding.

Weeding is necessary since weeds compete with the crop plants for water, nutrients, space and light.

• The manual removal includes physical removal of weeds by uprooting or cutting them close to the ground, from time to time.
• This is done with the help of a khurpi.
• A seed drill is also used to uproot weeds.

• Weeds are also controlled by using certain chemicals, called weedicides, like 2,4-D.
• These are sprayed in the fields to kill the weeds.
• They do not damage the crops.

1.8 Harvesting

• The cutting of crop after it is mature is called harvesting.
• In harvesting, crops are pulled out or cut close to the ground.
• It usually takes 3 to 4 months for a cereal crop to mature.

• Harvesting in our country is either done manually by sickle or by a machine called harvester.
• In the harvested crop, the grain seeds need to be separated from the chaff. This process is called threshing.
• This is carried out with the help of a machine called ‘combine’ which is in fact a harvester as well as a thresher.

Farmers with small holdings of land do the separation of grain and chaff by winnowing.

• The period of harvest is, thus, of great joy and happiness in all parts of India.
• Men and women celebrate it with great enthusiasm.
• Special festivals associated with the harvest season are Pongal, Baisakhi, Holi, Diwali, Nabanya and Bihu.

1.9 Storage

• Storage of produce is an important task.
• The harvested grains should be safe from moisture, insects, rats and microorganisms.

Hence, before storing them, the grains are properly dried in the sun to reduce the moisture in them. This prevents the attack by insect pests, bacteria and fungi.

Farmers store grains in jute bags or metallic bins. Large scale storage of grains is done in silos and granaries to protect them from pests like rats and insects.

Dried neem leaves are used for storing food grains at home. For storing large quantities of grains in big godowns, specific chemical treatments are required to protect them from pests
and microorganisms.

1.10 Food from Animals

We have seen that, like plants, animals also provide us with different kinds of food.

• Many people living in the coastal areas consume fish as a major part of their diet.
• Here we have just seen that the process of crop production involves a number of steps like selection of seeds, sowing, etc.
• Similarly, animals reared at home or in farms, have to be provided with proper food, shelter and care.
• When this is done on a large scale, it is called animal husbandry.

Animal husbandry: The animals reared at home or in farms, have to be provided with proper food, shelter and care. When this is done on a large scale, it is called animal husbandry.