When plants of the same kind are grown and cultivated at one place on a large scale, they are collectively called a crop. For example, a crop of wheat means that all the plants grown in a field are of wheat.
Crops that grow in the winters are called rabi crops. These crops get sown towards the end of October and their time period of growth is generally from October to March. These crops grow well in cold, dry weather and are harvested in the months of March and April. Examples of rabi crops are wheat, gram, pea, mustard and linseed.
Crops that are sown in the rainy season are called kharif crops. These crops are sown in July. Their time period of growth is generally from June to September. These crops grow well in warm, wet weather and are harvested in the month of October. Paddy, maize, soya bean, groundnut, cotton, etc., are examples of kharif crops.
These crops are sown in April and harvested in June or July. These are summer crops and are called Zayed crops. Examples are watermelon, pumpkin, gourds etc.
Paddy and maize
Wheat and gram
Kharif crops are grown in the beginning of the rainy season, in the months of June/July and Rabi crops are sown in the winter season, generally in October/November.
Kharif crops are harvested by September/October and Rabi crops are harvested by March/April.
A wheat crop does not require much water to grow. If wheat is sown in the kharif season when there is abundance of water due to rainfall, the excess water will destroy the seeds. Therefore, wheat would not grow in Kharif season.
The various steps involved in the growth of crops and storage of food grains, are collectively known as agricultural practices.
The process of loosening and turning of the soil is called ploughing or tilling.
The process of loosening and turning the soil is called ploughing. Plough, hoe and cultivator are used for ploughing the field.
A list of various agricultural practices is as follows:
a) Preparation of soil
c) Adding manure and fertilisers
e) Protection from weeds
Traditionally, a funnel-shaped like tool was used for sowing seeds. The seeds were filled into the funnel and passed down through two or three pipes having sharp ends. These ends pierced into the soil and placed the seeds there.
It is essential to maintain suitable distance between seeds so that the plants can get adequate resources for growth like sunlight, nutrients and water from the soil. Sometimes a few plants have to be removed to prevent overcrowding.
The following points need to be kept in mind while sowing seeds:
• Seeds should be of good quality, healthy, and free from diseases.
• They must be planted at a proper depth so that they can respire properly.
• Soil should be watered properly to help them germinate.
• Seeds should be sown at proper distances to get enough water, sunlight, and nutrients.
Seed drill is a better tool for sowing seeds because of the following reasons:
• It sows the seeds uniformly at suitable distances and depths.
• It ensures that seeds get completely covered by the soil after sowing. This prevents damage caused by birds.
• It also saves time and labour.
Preparation of soil is the first step in cultivation of crops for food production. Loosening and turning prepares the soil. The loose soil allows the plant roots to penetrate deep into the soil and as a result plants are held more firmly to the ground. It also helps the roots to breathe. The loosened soil helps in the growth of earthworms and microbes present in the soil. These earthworms are friends of farmers since they further help in loosening and turning the soil and also add humus to the soil.
Microbes decompose organic matter and turn them into nutrients for the plants to use.
Before sowing farmers select good quality seeds that are clean and healthy. Farmers prefer to use good quality seeds that give a high yield.
Seeds that have not developed properly have a lesser density and therefore they sometimes float on water.
Ploughing of field is done to loosen the soil. It has the following advantages:
a) The loose soil allows the plant roots to penetrate deep into the soil and as a result the plants are held more firmly to the ground.
b) It helps the roots to breathe easily.
c) The loosened soil helps in the growth of worms and microbes present in the soil. These organisms are friends of farmers since they further help in loosening and turning the soil and also add humus to the soil.
d) Ploughing also uproots and buries the unwanted plants called weeds that grow naturally alongside the main crops.
e) Ploughing also brings the nutrient rich soil to the top during loosening and turning of the soil.
The process of scattering seeds in the soil for growing crops is called sowing.
There are two methods of sowing the seeds in the soil:
a) Sowing by hand: Traditionally, farmers used to sow seeds by hand or with a funnel shaped tool. The seeds are put in at the top of the funnel from where they pass down a pipe with a sharp end, into the ground.
b) Sowing with a seed drill: Nowadays, modern farms use seed drills for sowing seeds. It has multiple pipes at regular distances, ensuring an even distribution of seeds.
The following precautions should be taken while sowing seeds in the soil:
a) The seeds should be sown at right intervals.
b) The seeds should be sown at a depth in the soil that is suitable for germination.
c) The seeds should not be sown into dry soil.
d) The seeds should not be sown into highly wet soil.
We can select good healthy seeds for sowing as follows. Put all the seeds in a bucket containing water and stir will. The seeds that settle down at the bottom of the bucket are healthy. Healthy seeds are heavy and so they sink in water.
At times seeds are first germinated and grown to seedlings in nurseries. Thus, they are protected from diseases, pests and germination problems. After sometime, the seedlings are planted in fields. The process of transferring the seedlings from the nursery and replanting them in the field is called transplantation. This practice is carried out in the cultivation of paddy crops and vegetables like tomatoes and chillies.
The advantages of transplantation in growing crops are as follows:
a) The seedlings are protected from diseases and pests until they are sufficiently matured.
b) Crop yield is maximized because only mature seedlings are planted in the fields thus avoiding germination failures from direct seeding.
The hoe is an agricultural implement that is used for removing weeds and for the loosening and turning of the soil. It has a long rod of wood or iron. The pole is attached to a bent plate. The plate works like a blade and helps to loosen the soil and remove weeds. It can be used manually or with a machine.
The cultivator is a tractor driven agricultural implement that is used for loosening and turning the soil in the fields. The top of the cultivator is attached to a tractor. The multiple iron tips at the end of the cultivator dig deep into the soil and help loosen it. This helps to plough a field much quicker than a traditional plough could. Nowadays, ploughing of large fields is done using the tractor driven cultivators.
Fertilisers are man-made chemical substances that are used to supplement essential plant nutrients that might not be present in the soil due to loss of soil fertility caused by soil erosion or over cropping. Examples of fertilisers include urea, ammonium sulphate, super phosphate, potash, NPK (Nitrogen, Phosphorus, Potassium).
Manure is a natural substance that improves the fertility of the soil by providing essential nutrients and humus to it. It is obtained from the decomposition of plant or animal wastes. It can be easily made by dumping plant and animal waste in pits in open places and allowing decomposition by earthworms and microbes present in the soil.
While the use of fertiliser can dramatically increase the yield of crops like wheat and rice, their overuse makes the soil less fertile by killing microbes and earthworms that help generate nutrients. The chemicals in fertilisers can also poison water bodies.
We can replenish the nutrients of the soil by manuring. Manure is an organic natural substance that improves the soil texture as well as its water retaining capacity by providing all the essential nutrients and humus to the soil.
Another method of replenishing nutrients in the soil is by crop rotation where nutrients consumed by a crop in a season are replenished by a dissimilar crop in the next season. For example, planting leguminous plants fixes the nitrogen content in soil, compensating for nitrogen consumed by the previous crop.
The advantages of using manure are as follows:
a) It makes the soil porous due to which the exchange of gases becomes easy.
b) It increases the presence of useful microbes in the soil.
c) It improves the soil texture and enhances the water holding capacity.
d) It does not create any pollution.
e) It provides all the essential nutrients to the soil.
The practice in which leguminous and non-leguminous crops are grown alternately in the same field as the main crops, is called crop rotation.
Advantages of crop rotation are as follows:
• It improves the fertility of the soil by replenishing the nitrogen content and thereby, increases the production of food grains.
• It saves a lot of nitrogenous fertilisers. This is because the leguminous crops grown during crop rotation can fix the atmospheric nitrogen with the help of rhizobium, which is a type of bacteria present in their root nodules.
Sukhbir should grow wheat and beans alternately in his field. When wheat is grown first, it takes away a lot of nitrogen from the soil for its growth and makes the soil nitrogen deficient. Next, when beans are grown, the rhizobium bacteria present in the root nodules of bean plants can fix the atmospheric nitrogen in the soil, thus replenishing the lost nitrogen content of the soil. And when wheat is again grown on the same field, it can utilise this extra nitrogen from the soil for its growth leading to an increase in food production.
It can be made at home.
It has to be bought in a market.
It is a natural substance obtained by the decomposition of plant or animal wastes.
It is a chemical salt that is prepared in chemical factories.
It does not contain harmful substances, as it is natural product.
It may contain substances that are harmful for the skin or the respiratory system.
It provides a lot of humus to the soil.
It does not provide humus to the soil.
It is not so rich in nutrients but helps the soil in the long run.
It is very rich in nutrients, but can harm the soil in the long run.
A modern system of irrigation; a sprinkler has rotating nozzles that are attached to a main pipe-line. When water flows under pressure through the pipe, it escapes from the rotating nozzles and irrigates the area around. It is very efficient for irrigating uneven surfaces and is useful in arid conditions.
Modern methods of irrigation help us to use water economically. These are:
(i) Sprinkler System
(ii) Drip system
The artificial supply of water to crops, at different intervals, is called irrigation.
The traditional methods of irrigation are
• Chain pump
The drip system is a modern irrigation method that uses pumps, valves and pipes to deliver water either right to the roots of the plants or to the soil surface near the roots. The water drips slowly, ensuring minimum wastage. It is the best technique for watering fruit plants, trees and gardens.
Wells, tube wells, ponds, lakes, rivers, dams and canals are some of the sources of irrigation.
In the drip system, the water falls in drops at the position of the roots. So, water is not wasted at all. Therefore, it is a boon in regions where availability of water is poor.
Irrigation is necessary because of the following reasons:
• It is necessary to maintain the moisture of soil for growing healthy crops.
• Water dissolves the nutrients present in the soil to form a solution which is then absorbed by the roots for the development of crops. Thus, irrigation is necessary to ensure the absorption of nutrients by the plants from the soil.
• Water supplied to the crops during irrigation also protects the crops from hot air currents and frost.
Unwanted plants that grow naturally along with the main crop plants are called weeds.
The process of removal of weeds is called weeding.
The best time for the removal of weeds is before they produce flowers and seeds.
The two methods are as follows:
a) Removal of weeds by manually pulling the weeds using hands.
b) Removal of weeds by using a trowel or khurpi.
Weeds consume large quantities of fertiliser, water, sunlight and space that are meant for crops. This reduces the crop yield and lowers the quality of food grains thus, affecting the growth of crops. Some weeds interfere in the harvesting process and may be poisonous for animals and human beings. Therefore, it is necessary to remove weeds from time to time.
Since weedicides are poisonous chemicals spraying them may affect the health of farmers. The chemicals should be sprayed carefully on the standing crops. While spraying, the person should cover his nose and mouth with a piece of cloth.
Cutting and gathering of the food crop after it is mature is called harvesting.
A modern machine called a harvester does harvesting.
The process of beating out the grains from the harvested crop is called threshing.
The process of beating out the grains from the harvested crop is called threshing.
The process of separating the grain seeds from the chaff and hay with the help of wind is called winnowing.
A combine is a huge machine which is a combined harvester and thresher. It is used to harvest and thresh crops at one go in large modern farms.