NCERT-Class 8- Science-Chapter-1-Crop Production and Management

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Cultivation of crops involves several activities undertaken by farmers over a period of time these are.

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

(i) Preparation of soil : It is the first method in crop management. Preparation of soil is done by loosening the soil by ploughing or tilling it. This allows the roots to penetrate deep in the soil and to breath easily even when they are deep. This will allow the seeds in growth and also for the growth of various bacteria and microorganism., which helps in the crop growth. This ploughing or tilling will help in being in the nutrient rich soil to the top, so that the seeds can derive nutrition for their growth.

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

The main tools used for this purpose are the plough, hoe and cultivator.

• Plough : This is being used since ancient times for tilling the soil, adding fertilisers to the crop, removing the weeds, scraping of soil, etc. This implement 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.
• Cultivator : Nowadays ploughing is done by tractor driven cultivator. The use of cultivator saves labour and time.

(ii) Sowing: Sowing is another important step after soil preparation. The process of putting seeds into the soil is called sowing. Best quality of seeds are used to sow for better crop yield. Seeds are sown with the help of a traditional tool or a seed drill. The tool used traditionally for sowing seeds is funnel-shaped. Nowadays a seed drill is used for sowing with the help of tractors. This tool sows the seed uniformly at a proper distance and depth.

(iii) Adding 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.

Fertiliser: Fertilisers are commercially available plant nutrients. They can be organic or inorganic in nature. They ensure healthy growth and development of plants by providing them with nitrogen, phosphorus, potassium, etc. The addition of fertilisers to the soil requires special guidelines such as dose time, post addition precautions, etc., to be followed. A fertiliser does not provide any humus to the soil. Its excessive use causes water pollution. It cannot replenish organic matter of soil.

Manure : Manure is a natural substance prepared by the decomposition of animal excreta and plant wastes. Manure is known to have a large quantity of organic materials and very little amount of plant nutrients. They help in enriching the soil with organic matter and nutrients. The addition of manure does not require any special guidelines. Manure provides humus to the soil and increases soil fertility. It protects the environment and helps in recycling farm waste. [/responsivevoice]

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(iv) Irrigation : The artificial method of watering the plants for assisting in their growth is called irrigation. Irrigation is the process in which water is supplied to the crops in the field at various intervals. The intervals vary from crop to crop, season to season and it also depends on the soil type and amount of rainfall. The irrigation sources are lakes, ponds, rivers, canals and dams.

Main sources of irrigation are wells, tube-wells, ponds, lakes, rivers.

Two methods of irrigation which help us to conserve water are:

(a) Sprinkler irrigation system: This irrigation system has an arrangement of vertical pipes with rotating nozzles on the top. It is more useful in the uneven and sandy land where sufficient water is not available.

(b) Drip irrigation system: This irrigation system has an arrangement of pipes or tubes with very small holes in them to water plants drop by drop just at the base of the root. It is very efficient as water is not wasted at all.

(v) Protecting from weeds : The undesirable and unwanted plants which grow naturally along with the crop are called weeds. The growth of weeds can be controlled by adopting many ways. Tilling before sowing of crops helps in the uprooting and killing of weeds, which may then dry up and get mixed with the soil. Weeds are also controlled by using certain chemicals, called weedicides. Weedicides are sprayed in the fields to kill the weeds.

Some important weeding methods are:

a. Weeds can be controlled using weedicides. It is a chemical, which is sprayed in the fields to kill all available weeds. Weedicides are not harmful to crops.
b. Tilling before sowing of crops also helps in removing weeds. Tilling uproots the weeds. The best time for the removal of weeds is before they produce flowers and seeds.
c. The manual method of removing weeds is with the help of a khurpi. It involves regular uprooting or cutting of weeds close to the ground.

(vi) Harvesting : The cutting of crop after it is mature is called harvesting. Harvesting 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.  Threshing is the last step in which the grains are separated from the chaff. It is done after the crop harvesting. There is a machine called “Combine” which carry out this work. Combine is combined harvester and thresher. It harvests crops and also separates the grains.

(vii) Storage : Proper storage of grains is necessary to protect them from pests and microorganisms. The fresh crop has
more moisture. 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.However, large scale storage of grainsis done in silos and granaries to protect them from pests like rats and insects

For storing large quantities of grains in big godowns, specific chemical treatments are required to protect them [/responsivevoice]

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Food is also obtained from animals for which animals are reared. This is called animal husbandry.

Animal husbandry includes taking care of animals, breeding them, and domesticating them for different purposes such as meat, wool, milk, eggs, honey etc.

Types of animal husbandry popular in India include:

• Beekeeping or Apiculture
• Cattle farming
• Dairy farming
• Fish Farming or Aquaculture
• Poultry farming
• Sheep farming

Breeding means mating animals with superior characters to create a new breed (or offspring that is more useful to us than its parents). Breeding can be of two types:

• Inbreeding
• Outbreeding [/responsivevoice]