Class 8 Chapter 1 : Crop production and management

Introduction

video Lecture - 1 :-

$\bigstar$ Green plant synthesize their food by photosynthesis process with the help of inorganic substance like carbon dioxide and water in the presence of sunlight.
$\bigstar$ Human being and other animals cannot make their own food. They need readymade food for nutrients like carbohydrates , fats and protein etc. for their growth and development
$\bigstar$ Human being obtained food from plant as well as animals.
$\bigstar$ Many types of plants are grown on large scale for food like wheat and rice etc. and this type of plant is called food grains.
$\Rightarrow$ Crops :-
when the same kind of plants are grown in the fields on a large scale to obtain foods like cereals (wheat , rice , maize) , pulse , vegetables and fruits etc, it is called a crop. It is also called “fasal (फसल)”
Examples :- crop of wheat means all the plants grown in the field are that of wheat.
$\bigstar$ Crops are grown in the soil in the field by the farmer(kissan).
Examples of crops :-
$\bigstar$ All living organism need food for their growth and survival.

i.Cereals crops :- wheat , paddy(rice) , maize , millet(Bajra , jawar) , barley
ii.Pulses :- Gram(chana) , peas , beans
iii.Oil seeds :- mustard , groundnut , sunflower
iv.Vegetables :- Tomato , cabbage , spinach.
v.Fruits :- Banana , grapes , guava , mango , orange , Apple

Types of Crops :-

Different crops grow in the different season of the year. For examples :- crops grow in the rainy season will not grow in the summer season.

Based on the season crops are categorised in the following groups :-

Kharif crops , and
Rabi crops

1. Kharif crops :-

The crops sown in the rainy season are called kharif crops
Grown in the month of June to September.
Sowing in June – July at the beginning of south – west monsoon.
Harvested at the end of monsoon season during September (October)
Examples :- paddy , maize , millet , soyabean , groundnut and cotton
It is also called summer crops.
Paddy is rice crops
Paddy requires lots of water so it grown in the rainy season .

2. Rabi crops :-

Grown in the month of October to march
Crops are harvested in the march
Examples :- wheat , gram , peas , mustard and linseed

$\Rightarrow$ Nomads :- the people who have no permanent homes and continuously moving from one place to another place.

$\Rightarrow$ Agriculture :- the growing of plants (crops) in the field for obtaining food is called agriculture.

Basic practices of crop production

video Lecture - 2

Agricultural practices :-

The various tasks performed by a farmer to produce a good crop are called agricultural practices.

Following is the agricultural practices for crop production :-

Preparation of soils
Sowing
Adding manure and
fertilizers
Removal of weeds
Harvesting , and
Storage of food grains

$\Rightarrow$ “Rotation of crops” is also one of agricultural practice which improve the fertility of soil and crop yield. Following are the description of all the agricultural practices

preparation of soil

$\bigstar$ Soil :- upper layer of the soil.

$\bigstar$ Soil provides minerals , water , air , humus and anchorage to the plants.

$\Rightarrow$ Preparation of soil for sowing the seeds of the crop are done by following steps :-

1. Ploughing
2. Levelling
3. Manuring

1. Ploughing :- process of loosening and turning the soil is called ploughing or tilling .

$\bigstar$ Plough :- ploughing is done by the instrument is called plough

$\bigstar$ Plough are made up of wood and iron , it have iron tip for penetration of the soil.

$\bigstar$ Plough is pulled by bullocks or tractor.
$\bigstar$ Ploughing is done by following reason :-

1. 1. Loose soil helps in expanding the roots of plants freely and deeper .
  2. Lots of air holds in the soil that’s why plants can breathe easily .
  3. The loose soil helps in the growth of worms and microbes present in the soil who are friends of the farmer since they help in further turning and loosening the soil. They also add humus to the soil.
  4. Ploughing also uproots and buries the weeds (unwanted plants) standing in the field and thereby suffocates them to death.
  5. The loosening and turning of soil during ploughing brings the nutrient rich soil to the top so that the plants can use these nutrients.

$\Rightarrow$ The mud crumbs are then broken down by using a soil plank called ‘crumb crusher’

$\Rightarrow$ The removal of top soil by wind and water is called ‘soil erosion’

$\Rightarrow$ The ploughed soil is levelled by pressing it with a wooden leveller (or an iron leveller) so that the top soil is not blown away by wind or drained off by water (and soil erosion is prevented). The levelling of ploughed soil is beneficial because of the following reasons:

1. The levelling of ploughed fields (by pressing) prevents the top fertile soil from being carried away by strong winds or washed away by rain water.
2. The levelling of ploughed fields helps in the uniform distribution of water in the fields during irrigation.
3. The levelling helps in preventing the loss of moisture from the ploughed soil.

$\Rightarrow$ The levelling of ploughed soil in the fields is done by using an implement called leveller.

$\Rightarrow$ ‘Manuring‘ means ‘adding manure to the soil’.

$\Rightarrow$ manure contains many nutrients required for the growth of crop plants. So, manuring is done to increase the fertility of the soil before seeds are sown into it. Once the soil is ploughed, levelled and manured, it is ready for the sowing of seeds. The soil is watered before sowing.

Lecture - 3 :-

Agricultural Implements

The loosening and turning of soil in the fields is done with the help of various agricultural implements (or tools). The main agricultural implements (or tools) used for loosening and turning the soil are: Plough, Hoe and Cultivator

PLOUGH

$\bigstar$ Plough is a large agricultural implement which is used for ploughing (or tilling) the soil in the fields

$\bigstar$ The wooden plough consists of a long leg of wood which is called plough shaft

$\bigstar$ Below the handle is a strong triangular iron strip called ploughshare.

$\bigstar$ the plough is drawn by a pair of bullocks (or other animals such as buffaloes, camels, etc.)

$\bigstar$ When the plough is pulled by the bullocks, the farmer holds the handle of the plough and presses down the handle due to which the ploughshare digs into the soil, loosens it and turns it.

HOE

Hoe is an agricultural implement (or tool) which is used for removing weeds, and loosening and turning the soil . Hoe consists of a long rod of wood or iron. There is a handle (having grip) at one end of the hoe. A strong, broad and bent plate of iron is fixed below the handle and acts like a blade. The other end of hoe has a beam which is put on the neck of bullocks. Thus, a hoe is also pulled by animals such as a pair of bullocks. The hoe is a kind of modified plough.

CULTIVATOR.

The cultivator is a tractor driven agricultural implement which is used for loosening and turning the soil in the fields quickly . cultivator has many ploughshares which can dig into a considerable area of soil at the same time, loosen it and turn it. Due to this, many fields can be ploughed (or tilled) in a short time by using a cultivator. In this way, the use of cultivator saves labor and time. Nowadays, ploughing of large fields is done by using the tractor driven cultivators .

sowing

Once the soil in the field has been prepared by ploughing, levelling and manuring, etc., seeds of the crop can be sown in it. The process of scattering seeds (or putting seeds) in the ground soil for growing the crop plants is called sowing. Sowing is the most important part of crop production. Before sowing, good quality seeds are selected. Good quality seeds are clean and healthy seeds free from infection and diseases. Farmers prefer to use seeds which give high yield of food grains.

Selection of Seeds

We can select good, healthy seeds for sowing as follows: Put all the seeds in a bucket containing water and stir well. Most of the seeds will settle down at the bottom whereas some seeds will float on top. The seeds which sink at the bottom of the bucket are the healthy seeds. On the other hand, the seeds which float on water are the spoiled seeds. This can be explained as follows: Healthy seeds are heavy, so they sink in water. The seeds which have been partially eaten by pests or damaged by disease become hollow and light, and hence float on water. The seeds may also be treated with fungicide solutions before sowing to prevent the seed-borne diseases of crops.

Methods of Sowing Seeds

Seeds are sown in the soil either by hand or by seed drill. Thus, there are two methods of sowing the seeds in the soil. These are:

Sowing by hand, and
Sowing with a seed drill.

The sowing of seeds by hand (or manually) is called broadcasting. In the sowing with hand or manually, the seeds are taken in hand and gradually scattered in the entire ploughed field. This method is, however, not very good because there is no proper spacing or proper depth at which the seeds are sown by hand. Moreover, the seeds scattered on the surface of the soil for sowing can be picked up and eaten by the birds.

The implement used for sowing is a seed drill. A seed drill is a long iron tube having a funnel at the top . The seed drill is tied to back of the plough and seeds are put into the funnel of the seed drill. And as the plough makes furrows in the soil, the seeds from the seed drill are gradually released and sown into the soil furrows made by the plough. Thus, by using a seed drill for sowing, the seeds are sown at the correct depth and correct intervals (or spacings). The seeds sown with a seed drill are in regular rows. Moreover, when the seeds are sown in furrows by a seed-drill, the seeds get covered by soil.

Due to this, these seeds cannot be picked up and eaten by the birds. It is obvious that the sowing with seed-drill is much better than sowing by hand. A bullock driven seed-drill has just one long iron tube with a funnel. The tractor driven seed-drill has 5 to 6 iron tubes joined together with a common funnel at the top . When the seeds are put into the funnel of such a seed drill, the seeds are released through all the tubes and get sown into 5 or 6 furrows of soil simultaneously. By using such tractor driven seed-drills, the sowing of seeds can be completed quickly. Most of the crops like wheat, gram (chana), maize and millet etc, are grown (or cultivated) by sowing the seeds directly into soil.

Precautions for Sowing Seeds

The following precautions should be taken while sowing seeds in the soil.

The Seeds Should be Sown at Right Depth in the Soil Suitable For Germination. If the seeds are just spread on the surface of the soil, then the seeds will be eaten up by the birds. And if the seeds are sown too deep, then they may not germinate because they cannot breathe (cannot get sufficient air) at greater depth. So, the seeds should be sown at right depth in the soil which is suitable for germination. This right depth is learnt by experience.
The Seeds Should be Sown at Right Intervals or Spacings. The seeds should neither be placed too close nor too far apart. This is because if the seeds are sown too close, then plants formed from them will also be too close, and will not get enough sunlight, water, and other nutrients. Thus, an appropriate distance between the seeds is important to avoid overcrowding of plants. This allows the plants to get sufficient sunlight, nutrients and water from the soil. On the other hand, if the seeds are sown too far apart, then it will be a wastage of field space.
The Seeds Should Not be Sown in a Dry Soil. Moisture in the soil is necessary for the germination of seeds. So, if seeds are sown in a dry soil, they may not germinate at all.
The Seeds Should Not be Sown in a Highly Wet Soil. If the seeds are sown in a highly wet soil, then on drying, the soil surface becomes hard and because of this hard surface of soil, the germinating plumule will be unable to come out of ground. Moreover, the seeds are not able to respire properly due to lack of air under these conditions of hard surface of soil.

Advantages of Sowing with a Seed Drill

The sowing of seeds with a seed drill has the following advantages:

By using a seed drill for sowing, the seeds are sown at correct depth and correct intervals (or spacings).
The seeds sown with a seed drill are in regular rows.
When the seeds are sown in furrows by a seed drill, the seeds get covered by soil and hence these seeds cannot be picked up and eaten by birds. This prevents damage caused by birds.
Sowing by using a tractor-driven seed drill saves time and labour.

video Lecture - 4 :-

Transplanting (or Transplantation)

Though most of the crops are grown by sowing the seeds directly in the soil but in some crops like paddy (rice) and many vegetables, the seeds are not directly sown in the soil in large fields. In the case of crops like paddy (rice) and vegetables like tomatoes and chillies (mirch), the seeds are first sown in a small plot of land or nursery and allowed to grow into tiny plants called seedlings by providing them with a good dose of nutrients. After the seeds have grown into tiny plants called seedlings in the seed-bed or nursery, only the healthy and well developed seedlings. are then picked out from the nursery bed and transferred or transplanted to the regular field.

The process of transferring the seedlings from the nursery to the main field by hand is called transplantation or transplanting. During transplantation, proper distance is kept between the various seedlings and also between the various rows of seedlings, to enable each and every plant (formed from seedlings) to get sufficient sunlight, water and other nutrients for normal and healthy growth . The process of transplantation gives us many advantages over the direct sowing which ultimately leads to an increase in the yield of the crop. Paddy seedlings being transplanted in the fields. The various advantages of the transplantation process are given below:

The process of transplantation enables us to select only the better and healthy seedlings for the cultivation of crops. The bad seedlings can be rejected. This selection is, however, not possible when the seeds are directly sown in the soil.
The process of transplantation allows better penetration (deeper penetration) of the roots in the soil.
The process of transplantation promotes better development of the shoot system of plants.
The process of transplantation allows the seedlings to be planted at the right spacings so that the plants may get uniform dose of sunlight, water and nutrients.

The practice of transplantation is used in the cultivation of paddy crop (rice crop) and in the cultivation of many vegetables like tomatoes and chillies. We will now discuss manures and fertilisers.

Adding manure and fertilizers

The crop plants need a number of mineral elements for their growth which they get from the soil through their roots. Now, repeated growing of crops in the same field removes a lot of precious mineral elements, organic matter and other materials from the soil. Due to this the soil becomes infertile after some time, and the crop yield decreases. So, unless the depleted plant nutrients are put back into the soil from time to time, the growth of crop would be poor. The deficiency of plant nutrients and organic matter in the soil is made up by adding manures and fertilisers to the soil.

Manures

Manure is a natural fertilizer. A manure is a natural substance obtained by the decomposition of animal wastes like cow-dung, human wastes, and plant residues, which supplies essential elements and humus to the soil and makes it more fertile. Manures are prepared from animal wastes, human wastes and plant residues by the action of micro-organisms. In order to prepare manure, farmers dump animal wastes (animal dung, etc.) and plant wastes (like leaves, etc.) in pits at open places and allow it to Manures contain a mixture of various nutrient elements and a lot of organic matter (humus) recycled from bio-mass wastes (animal and plant wastes). Though manures are not very rich in plant nutrients like nitrogen, phosphorus and potassium, but they are rich in organic chemical nutrients like humus. Thus, manures provide a lot of organic matter like humus to the soil and this humus improves the physical and chemical properties of the soil. A manure improves the soil texture for better retention of water and aeration. This is because, being porous, humus can hold more water and air in the soil. In fact, manure makes up the general deficiency of the nutrients in the soil.

A manure is, however, very bulky and voluminous due to which it is inconvenient to store and transport. Moreover, a manure is not “nutrient specific”, and hence it is not much helpful when a particular nutrient is required in the soil for a particular crop. A chemical fertiliser, on the other hand, is nutrient specific

Chemical fertilizers

Manures are not able to supply the required quantities of the essential plant nutrients like nitrogen, phosphorus and potassium, etc. So, they are to be supplemented with chemical fertilisers. A chemical fertiliser is a salt or an organic compound containing the necessary plant nutrients like nitrogen, phosphorus or potassium, to make the soil more fertile. A chemical fertiliser is rich in a particular plant nutrient (such as nitrogen, phosphorus or potassium). Some examples of fertilisers are: Urea, Ammonium sulphate, Superphosphate, Potash and NIPK (N = Nitrogen; P = Phosphorus; K = Potassium).

The chemical fertilisers are nutrient specific. This means that a chemical fertiliser can provide only nitrogen, only phosphorus or only potassium to the soil, as required. The chemical fertilisers have plant nutrients in a concentrated form. So, they provide quick replenishment of plant nutrients in the soil and restore its fertility. Chemical fertilisers have high solubility in water. So, they are easily absorbed by the plants. Chernical fertilisers are made in factories. Chemical fertilisers are easy to transport, store and handle

because they come in bags . The chemical fertilizers absorb moisture very quickly, so they are packed in air-tight bags.

The chemical fertilizers can be applied before sowing, during irrigation or sprayed on standing crops. The use of fertilizers has helped the farmers to get better yield of crops such as wheat, paddy (rice) and maize, etc. The excessive use of fertilizers is harmful due to the following reasons:

(i) The excessive use of fertilizers changes the chemical nature of soil and makes the soil less fertile. For example, the excessive use of fertilizers can make the soil highly acidic or alkaline. The highly acidic or alkaline soil becomes less fertile.
(ii) The excessive use of fertilizers causes water pollution in ponds, lakes and rivers, etc.

In order to maintain the fertility of soil, we should substitute some of the fertilizers by organic manure or leave the field fallow (uncultivated) in-between two crops. When a field is kept uncultivated for some time, its fertility is restored naturally.

Before we end this discussion, we would like to give the main differences between manures and fertilisers in tabular form.

Differences between Manures and Ferilisers

Manure

A manure is a natural substance obtained by the decomposition of animal wastes like cow dung, human waste, and plant residues.
A manure is not very rich in essential plant nutrients like nitrogen, phosphorus and potassium.
A manure provides a lot of organic matter like humus to the soil.
A manure is absorbed slowly by the plants because it is not much soluble in water.
Manure can be prepared in the fields

Fertifier

A fertilizer is a salt or an organic compound.
Fertilizers are very rich in plant nutrients like nitrogen, phosphorus and potassium.
A fertilizer does not provide any humus to the soil.
Being soluble in water, a fertilizer is readily absorbed by the plants.
Fertilizers are prepared in factories.

Advantages of Manure

The manure is an organic material. The organic manure is considered better than fertilisers because of the follwing reasons:

Manure enhances the water-holding capacity of the soil.
Manure makes the soil porous due to which the exchange of gases becomes easy.
Manure increases the number of useful microbes in the soil .
Manure improves the texture of the soil.

Another method of replenishing the soil with nutrients (such as nitrogen) is through crop rotation. Before we discuss crop rotation as a means of improving the fertility of soil, we should know something about leguminous plants or leguminous crops. The pulses, peas, beans, groundnut, gram (chana) and clover (berseem) are leguminous crops. The root nodules of leguminous plants have nitrogen-fixing bacteria (called Rhizobium bacteria) which can directly fix (or convert) the nitrogen gas present in air to form nitrogen compounds. In other words, leguminous crops have the ability to fix atmospheric nitrogen to form nitrogen compounds. These nitrogen compounds go into the soil and improve its fertility. Some of these nitrogen compounds are used by the leguminous crop for its own growth and the rest of nitrogen compounds are left in the soil. Thus, planting a leguminous crop like pulses, peas, beans, groundnut, gram and clover, etc., in a field results in nitrogen-rich soil.

The planting of a leguminous crop in a field has the same effect as adding nitrogenous fertiliser in the field. Since leguminous crops can fix the atmospheric nitrogen themselves by using nitrogen-fixing bacteria present in their root nodules, therefore, nitrogenous fertiliser is not required for growing leguminous crops. On the other hand, cereal crops like wheat, maize, paddy, and millet, etc., are non- leguminous crops which do not have the ability to fix (or convert) the nitrogen gas of air into nitrogen compounds. Keeping these points in mind, we will now describe crop rotation.

Crop Rotation

The fertility of soil can be improved by crop rotation. The practice in which different types of crops (leguminous crops and non-leguminous crops) are grown alternately in the same field or soil is called crop rotation. In crop rotation, the cereal crops like wheat, maize, paddy and millet are grown alternately with leguminous crops like pulses, peas, beans, groundnut and clover, etc., in the same field. For example, when a cereal crop like maize crop is grown first, it takes away a lot of nitrogen from the soil for its growth and makes the soil nitrogen deficient. And next, when the leguminous crop like pulses or groundnut is grown in the same field, then the leguminous crop with its nitrogen fixing bacteria, enriches the soil with nitrogen compounds and increases its fertility. And when another cereal crop like wheat is grown after that, then wheat can utilise this extra nitrogen from the soil for its growth and produce a bumper crop. In this way, rotating different crops (leguminous and non-leguminous crops) in the same field replenishes the soil with nitrogen naturally and leads to increase in the crop production. Rotation of crops has the

following advantages:

Rotation of crops improves the fertility of the soil by replenishing it with nitrogen and hence brings about an increase in the production of food grains.
Rotation of crops saves a lot of nitrogenous fertilizer. This is because the leguminous crops grown during the rotation of crops can fix atmospheric nitrogen with the help of their nitrogen fixing bacteria, and there is no need to add nitrogenous fertilizer to the soil.

video Lecture - 5 :-

Irrigation

All the crop plants need water for their growth. The crop plants absorb water from the soil. The amount of water in the soil is not constant throughout the year. Water from the soil is lost constantly by evaporation and percolation to lower depths of the ground. It is, therefore, necessary to supply water to the crop plants in the fields, periodically. The process of supplying water to crop plants in the fields is called irrigation, Just as we cannot survive without water for a long time, in the same way, plants also cannot survive without water for a long time. For example, if we stop watering plants grown in our home for a considerable time, the plants become pale, wilt and ultimately die. Water is absorbed by the roots of the plants. Along with water, minerals and fertilisers are also absorbed by crop plants. Plants contain nearly 90 per cent water.

Why is Irrigation Necessary

Irrigation before ploughing the fields makes the soil soft due to which the ploughing of fields becomes easier.
Irrigation is necessary to provide moisture for the germination of seeds. This is because seeds do not grow in dry soil.
Irrigation is necessary to maintain the moisture of soil for healthy crop growth so as to get good yield
Irrigation is necessary for the absorption of nutrient elements by the plants from the soil. The irrigation water dissolves the nutrients present in the soil to form a solution. This solution of nutrients is then absorbed by the roots for the development of plants.
Water supplied to the crops during irrigation protects the crop plants from hot air currents as well as frost.

Factors Affecting Irrigation Requirements of Crops

The irrigation requirements (or water requirements) of crops depend on three factors:

Nature of the crop,
Nature of the soil, and
Season.

Each crop needs a specific amount of water during the various stages of its growth and ripening. Some crops need more water whereas others require less water. For example, paddy crop (rice crop) is transplanted in standing water and requires continuous irrigation whereas other crops like wheat, gram (chana) and cotton, etc., do not require so much water. For cereal crops like wheat, irrigation is needed at only three stages: before ploughing the field; at the time of flowering; and at the time of development of grain.

There are two important types of soils in which the crops are grown; Sandy soil and Clayey soil. The crops grown in a sandy soil need irrigation more frequently whereas the frequency of irrigation for the crops grown in a clayey soil is comparatively less. This can be explained as follows: Sandy soil is highly porous having high permeability. So, when we irrigate the crops standing in a sandy soil, then water quickly percolates down the soil and the crop plants are not able to absorb adequate amount of water. So, due to the poor water retaining capacity of the sandy soil, the crops cultivated in sandy soil need more frequent irrigation. On the other hand, clayey soil is much less permeable than sandy soil due to which it can retain water for a much longer time. So, when the crop grown in a clayey soil is irrigated, the water remains in the soil for a longer time, and hence the plants can absorb this water in adequate amount. So, due to better water retaining capacity of the clayey soil, the crops cultivated in clayey soil need irrigation less frequently.

The frequency of irrigation of crops alsq varies from season to season. For example, the frequency of Irrigation (or watering) of the crops is higher in summer season. This is because during the hot days of summer, the rate of evaporation of water from the soil and the leaves of crop plants is increased. On the other hand, the frequency of irrigation (or watering) of the crops is comparatively lower in the colder winter season

Sources of Irrigation

Crops are supplied water for irrigation from different sources like: Rivers, Canals, Wells, Tube-wells, Dams (Reservoirs), Ponds and Lakes. Even rain is a source of irrigation of crops. The water available in wells, lakes and canals is lifted up by different methods in different regions for taking it to the fields.

Traditional Methods of Irrigation

The various traditional methods of irrigation are:

Moat (Pulley system),
Chain pump,
Dhekli, and
Relief (Lever system).

MOAT. In the moat system of irrigation, water is drawn out from a well by using a big container tied to a long rope which moves over a pulley fixed at one edge of the well . The rope tied to container is usually pulled by animals such as bullock (buffalo or camel). When the rope is pulled at the free end, the container filled with water (tied at the other end of rope) comes out of the well .

The farmer pours out water from the container into the fields and lowers empty container back into the well to get it refilled. The water-filled container again comes out of the well when the bullock pulls the rope and this process is repeated to get a continuous supply of water for irrigation.

CHAIN PUMP. Chain pump is an arrangement to lift water from a source of water like a stream, pond or lake (which is at a lower level than the fields) so as to provide irrigation in the fields. A chain pump consists of two large wheels, one fixed at the lower level of water source and the other fixed at the higher level above the fields. The two wheels are connected by a chain passing over them. On the chain are hung small buckets. Below the bottom wheel is the source of water (like a stream, pond or lake) from which the water is to be lifted up to the fields. A handle is attached to the axle of the upper wheel. When the handle attached to the upper wheel is rotated by the farmer, the wheels connected by the chain start turning. When the lower wheel turns, the buckets attached to chain dip in the stream and get filled with water . The moving chain then lifts these buckets filled with water up to the upper

wheel where the buckets tilt, and get emptied in the fields to provide water for irrigation. The moving chain then carries the empty buckets down to the lower wheel to be filled with water again. This process is repeated due to which the water from stream (pond or lake) is continuously lifted up into the fields. DHEKLI. Dhekli is an arrangement to lift water from

shallow wells by using the principle of simple lever (The word ‘dhekli’ means ‘lever-beam of well). In dhekli, a long wooden beam is supported over a forked vertical support fixed in the ground near the well in such a way that its longer arm is towards the well and shorter arm away from it . A bucket is tied to the end of longer lever arm with a rope in such a way that it hangs over the mouth of the well. A weight is tied to the end of shorter lever arm. In order to lift water from the well, the end of longer lever arm carrying the bucket is pulled down by the rope. When the bucket is lowered into the well, it gets filled with water. On releasing the rope, the weight attached to the end of shorter lever arm comes down and lifts the water-filled bucket out of the well. The farmer then gets hold of the bucket, tilts it and pours out its water into the field. This
process is repeated so as to get a large amount of water from the well required for irrigation.

RAHAT (LEVER SYSTEM). In the rahat system of irrigation, water is drawn out from a well. In this method, there is a large wheel fixed on an axle above the mouth of the well . A long belt with many, many small metal pots is put over the circumference of big wheel which can move over the wheel when the wheel turns. The lower end of the long belt of pots dips in the water of the well. The big wheel is turned by using a lever system driven by the force of bullocks (or other animals such as buffalo or camel). When the bullocks move the long, horizontal handle of the lever-system going round and round, the big wheel fixed over the mouth of well starts rotating. When the wheel rotates, the water filled pots come out of the well one after the other, go over the wheel, come downward, pour water in a channel, get emptied and then go down again into the well to bring out more water . The water brought out by the pots connected to a continuously rotating belt is used for irrigation in the fields.

The Use of Pumps For Irrigation

The human labour or cattles are used to lift water in the traditional methods of irrigation. So, the traditional methods of irrigation are cheaper but less efficient. The traditional methods of irrigation are not used much these days. These days, pumps are commonly used for lifting water (from wells, ponds, lakes, streams and rivers). These pumps are run by electricity, diesel, blogas or solar energy. When a pump is used to draw out water from a narrow well, it is called a tube-well. Nowadays, tube- wells are being used increasingly for lifting underground water to be used for irrigation in agriculture .

Modern Methods of Irrigation

Tube-well.

The modern methods of irrigation help us to use water economically (by preventing its wastage). The two main modern methods of irrigation are:

(i) Sprinkler system, and
(ii) Drip system.

SPRINKLER SYSTEM.

In the sprinkler system of irrigation, a main pipeline is laid in the fields. Perpendicular pipes having rotating nozzles at the top are joined to the main pipeline at regular intervals. When water from a tube-well is allowed to flow through the main pipeline under pressure with the help of a pump, it escapes from the rotating nozzles . This water gets sprinkled on the crop plants as if it is raining. The sprinkler system of irrigation is more useful for the uneven land where sufficient water is not available. The sprinkler system is also very useful for sandy soil.

DRIP SYSTEM.

In the drip irrigation system, there is a network of narrow pipes (or tubes) with small holes, in the fields . When water flows through the narrow pipes, it falls drop by drop at the position of roots of the plants. This water is absorbed by the soil in the root zone of the plants and utilised by the plants. There is no run-off (or wastage) of irrigation water. Drip system is the best technique for watering (or irrigating) fruit plants, trees and gardens. Drip irrigation system has the following advantages:

(1) Drip system provides water to plants drop by drop. So, water is not wasted at all.
(ii) Drip system minimizes the use of water in agriculture. So, drip system of irrigation is very useful in those regions where the availability of water is poor.

We will now discuss the removal of weeds from crop fields.

Removing the weeds (or weeding)

When we grow a food crop in the field, then in addition to the crop plants, many small, unwanted plants also germinate and grow in the field naturally. The unwanted plants (or wild plants) which grow along with a cultivated crop are called weeds . The growth of weeds in the fields is harmful because they consume a lot of fertilizer, water, sunlight and space, meant for the crop plants and reduce the crop yield, and lower the quality of food grains. Since the presence of weeds in the fields will reduce the crop-yield, therefore, it is necessary to remove them from time to time. Though most of the weeds get uprooted during the ploughing of fields but they reappear when the crop grows. The weeds multiply and spread very fast because they produce a large quantity of seeds.

The type of weeds vary from field to field, from crop to crop, and also from season to season. Some of the common weeds (unwanted plants) found in wheat and rice fields are:

(1) Wild oat (Javi)
(ii) Grass (Glass)
(iii) Amaranthus (Chanlai)
(iv) Chenopodium (Bathun)

Since weeds are harmful to the crops, they must be removed from the fields. The process of removing weeds (unwanted plants) from a crop field is called weeding. Weeding is necessary because weeds compete with crop plants for water, nutrients, light and space, and hence affect the growth of the crop. Some weeds are poisonous for human beings and animals whereas some weeds interfere in harvesting. The best time for the removal of weeds is before they produce flowers and seeds. Weeding is done by hand or with the help of implements like trowel (khuurpa). Weeds can also be destroyed (or controlled) by spraying special chemicals called weedicides in the crop fields. Thus, the various methods of weeding (controlling weeds or eradicating weeds) are as follows

1. Removal of Weeds by Pulling Them Out With Hand.

Weeds can be removed from the crop fields just by pulling them up with hands . When we pull the weeds, they get uprooted from the field. These uprooted weeds can then be thrown away.

2. Removal of Weeds by Using a Trowel (Kharpa).

Weeds can be removed by digging or cutting them close to the ground from time to time with the help of an implement called trowel (or khurpa). A trowel (or kharpa) is shown in Figure 23

3 Destroying the Weeds by Spraying Special Chemicals Called Weedicides.

The poisonous chemicals which are used to kill weeds (unwanted plants) in the fields are called weedicides. Some of the common weedicides are: 2,4-D, MCPA and Butachlor. A solution of the weedicide in water is sprayed on the standing crops in the fields with a sprayer . The weedicides kill (destroy) the weeds (unwanted plants) but do not damage the main crop. The weedicides are sprayed in the crop fields before the flowering and seed formation in the weeds takes place. Since weedicides are poisonous chemicals, therefore, spraying of weedicides may affect the health of the person who handles the weedicide sprayer. The weedicides should be sprayed or the standing crops very carefully. During the spraying of weedicides, the person should cover his nose and mouth properly with a piece of cloth (so as to prevent the inhaling of poisonous weedicide).

Harvesting

It normally takes about three or four months for a food crop to mature. Lush green wheat fields and paddy fields turn to golden yellow at the end of this period . This change in colour from

green to golden is due to the maturity of crop or ripening of crop. Once the crop has matured then it is ready for cutting and gathering. The cutting and gathering of the matured food crop is called harvesting. In harvesting, the crops like wheat or rice are cut close to the ground by hand using a cutting tool called sickle. This is called manual harvesting. In large fields, wheat and paddy crops are cut by a motorized machine called harvester.

After harvesting the crap, the next step is threshing. The process of beating out the grains from the harvested crop plants is called threshing. Threshing is done to take out the grain from its outer covering called chaff. In the traditional method of threshing, the harvested crop is spread on the ground in a small area and various cattle like bullocks, buffaloes and camels are made to walk over it again and again in a circle. The cattle’s feet crush the harvested crop plants due to which the chaff breaks up and the grain comes out. During threshing, the leaves and stems of the crop plants are converted into very small pieces called hay which is used as a fodder for animals. In larger farms, a motorized machine called thresher is also used for the threshing process.

Though the process of threshing brings out grains from the cut and dried crop plants, but this grain is mixed with chaff (outer inedible covering of grain) and hay, and has to be cleaned by separating from chaff and hay, before it can be used. This is done by the process of winnowing. The process of separating grain from chaff and hay with the help of wind is called winnowing. When the grain mixed with chaff and hay is made to fall from a height in blowing wind, the grain, being heavy, falls straight to the ground, whereas the chaff and hay, being much lighter, are carried some distance away by the wind. In this way, the grains form a separate heap and can be collected and packed in gunny bags.

These days ‘combines’ (also called combine harvesters) are being used in large farms for harvesting related operations . A combine is a huge machine which cuts the standing cereal crop (like wheat) in the fields, threshes it and separates the chaff from grain in one operation. This grain is clean and can be directly filled in gunny bags (and there is no need of winnowing). One of the disadvantages of using the machines like ‘combines’ is that it reduces the yield of hay (bhoosa) which is used as a fodder for cattle.

This is a ‘combine’. The combine’ is combined harvester and thresher’

is because the combines cut only the upper part of the standing crop, and not from near the ground. The stubs of crop plants left in the fields after harvesting are sometimes burning of stubs is harmful due to two reasons: burnt by the farmers.

(i) The burning of stubs of crop plants in the fields causes air pollution.
(ii) The burning of stubs in the fields may cause accidental fire to the harvested crop lying in the fields and damage it.

Harvest Festivals.

When the crops mature and become ready to be harvested, the fields turn golden yellow. The sight of golden fields of standing crops, laden with grains, fills the hearts of farmers with joy. The period of harvest is of great joy and happiness in all the parts of India. Men and women celebrate the harvest season in the form of festivals. The special festivals in India associated with the harvest seasons are: Pongal, Baisakhi, Holi, Nabanya, and Bihu. We will now discuss the storage of food grains.

Storage of food grains

The fresh food grains (like wheat) obtained by the harvesting of crops contain more moisture than required for their safe storage. So, the food grains (like wheat) obtained by harvesting the crops are dried in the sunshine before storing, to reduce their moisture. It is necessary to reduce the moisture content of grains before storing to prevent their spoilage during storage. This is because the higher moisture content in food grains promotes the growth of fungus and moulds on the stored grains which damages them (and makes them lose their germination capacity). The farmers store the dried food grains at home in metal bins (metal drums) and jute bags (called Figure 28. These are wheat grains (a kind gunny bags). Dried neem leaves are used for storing food grains at of food grains) obtained by harvesting home. For example, when wheat is stored at home in iron drums, and threshing wheat crop.

then some dried neem leaves are put in it. Dry neem leaves protect the stored food grains from pests such as insects and micro-organisms. The Government Agencies like Food Corporation of India (FCI) buy grains from farmers on large scale and store it in big godowns so that it can be supplied throughout the country, round the year. The large scale storage of food grains (like wheat and rice) is done in two ways:

in gunny bags, and
in grain silos.

The most common method of storing food grains on a large scale is to fill them in gunny bags, stitch the mouth of gunny bags tightly, and keep these gunny bags one over the other in big godowns . Pesticide solutions are sprayed on the stacked gunny bags in the godown from time to time to protect

the grains from damage by pests during storage. The population of rats in the godown is also controlled by killing them with rat poison from time to time. Though a gunny bag is not an ideal container for food grains but its greatest advantage is that food grains filled in gunny bags can be easily transported and distributed at various places.

In addition to the gunny-bag method of storing food grains, the grain-silos are also used for storing food grains on large scale (or bulk storage of food grains). The grain-silos are specially designed big and tall cylindrical structures . The grain-silos have inbuilt arrangements for the protection of stored food grains from pests (like insects) and micro-organisms.

food from animals

Though we get most of our food from crop plants, animals also provide us food. The food provided by animals consists of Milk, Eggs and Meat. The food obtained from animals is very rich in proteins. In fact, animal food provides certain proteins which are not present in plant foods. Most of the food obtained from animals also contains a good amount of fat but it contains very little of carbohydrates. Animal food, however, contains minerals and vitamins. The food obtained from animals is more expensive than that obtained from plant sources. The animals which provide us food are mainly of two types:

Milk yielding animals (or Milch animals), and
Meat and Egg yielding animals.

The examples of milk yielding animals (or milch animals) are: Cow, Buffalo and Goat. Milk is a perfect natural diet. Milk and its products (called dairy products) like Butter, Ghee, Curd and Cheese are highly nutritious foods. The examples of meat and egg yielding animals are: Goat, Sheep, Fish, and Poultry (Chicken, Hen and Duck). Out of these animals, goat, sheep and fish give us meat. Poultry gives us meat as well as eggs. Honey is another nutritious food obtained from animals. It is obtained from insects called ‘bees’ (or honeybees).

Animal Husbandry

Just as each crop has its own requirements of proper soil, irrigation, manures and fertilizers and weedicides, in the same way, each domestic animal has its own needs of food, shelter, and health care. The branch of agriculture which deals with the feeding, shelter, health and breeding of domestic animals is called animal husbandry. The various practices necessary for raising animals for food and other purposes

(or the elements of animal husbandry) are:

Proper feeding of animals,
Proper shelter for animals,
Prevention and cure of animal diseases, and
Proper breeding of animals.

Milk giving animals (milch animals or milch cattle) like cows and buffaloes are reared on small scale in rural homes. On a large scale, they are reared in big dairy farms

Fish as Food

Fish is an important source of animal food. Many people living in the coastal areas (sea-side areas) consume fish as a major part of their diet. Fish is rich in proteins. It is a highly nutritious and easily digestible food. Fish liver oil is rich in vitamin A and vitamin D. For example, Cod liver oil (or Cod fish liver oil) is rich . Fish is an important source of in vitamin A and vitamin D. We are now in a position to answer animal food.

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