science textbook#1 chapter1.pdf

CROP PRODUCTION AND MANAGEMENT P aheli and Boojho went to their uncle’s house during the summer vacation. Their uncle is a farmer. One day they saw some tools like khurpi, Food has to be produced on a...

CROP PRODUCTION AND MANAGEMENT P aheli and Boojho went to their uncle’s house during the summer vacation. Their uncle is a farmer. One day they saw some tools like khurpi, Food has to be produced on a large sickle, shovel, plough, etc., in the field. scale. In order to provide food for a large population— regular production, proper I want to know management and distribution is where and how we necessary. use these tools. 1.1 Agricultural Practices You have learnt that all living organisms require food. Plants can make T ill 10,000 B.C.E. people were their food themselves. Can you recall nomadic. They were wandering in how green plants synthesise their own groups from place to place in search food? Animals including humans can of food and shelter. They ate raw not make their own food. So, where do fruits and vegetables and started animals get their food from? hunting animals for food. Later, they But, first of all why do we have to eat could cultivate land and produce rice, food? wheat and other food crops. Thus, You already know that energy from was born ‘Agriculture’. the food is utilised by organisms for carrying out their various body When plants of the same kind are functions, such as digestion, respiration cultivated at one place on a large scale, and excretion. We get our food from it is called a crop. For example, crop of plants, or animals, or both. wheat means that all the plants grown in a field are that of wheat. You already know that crops are of different types like cereals, vegetables and fruits. These can be classified on the Since we all need food, basis of the season in which they grow. how can we provide India is a vast country. The climatic food to a large number conditions like temperature, humidity of people in our and rainfall vary from one region to country? another. Accordingly, there is a rich 2024-25 variety of crops grown in different parts to as agricultural practices which are of the country. Despite this diversity, listed below: two broad cropping patterns can be (i) Preparation of soil identified. These are: (ii) Sowing (i) Kharif Crops : The crops which are (iii) Adding manure and fertilisers sown in the rainy season are called (iv) Irrigation kharif crops. The rainy season in India (v) Protecting from weeds is generally from June to September. (vi) Harvesting Paddy, maize, soyabean, groundnut and (vii) Storage cotton are kharif crops. (ii) Rabi Crops : The crops grown in the 1.3 Preparation of Soil winter season (October to March) are called rabi crops. Examples of rabi The preparation of soil is the first step crops are wheat, gram, pea, mustard before growing a crop. One of the most and linseed. important tasks in agriculture is to turn Besides these, pulses and vegetables the soil and loosen it. This allows the are grown during summer at many roots to penetrate deep into the soil. The places. loose soil allows the roots to breathe easily even when they go deep into the 1.2 Basic Practices of Crop soil. Why does the loosening of soil allow Production the roots to breathe easily? 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. Why paddy can not be grown in the winter season? But why the soil needs to be turned and loosened? You have learnt in the previous classes that soil contains minerals, water, air and some living organisms. Paddy requires a lot of In addition, dead plants and animals water. Therefore, it is grown get decomposed by soil organisms. In only in the rainy season. this way, various nutrients in the dead organisms are released back into the Cultivation of crops involves several soil. These nutrients are again absorbed activities undertaken by farmers over a by plants. period of time. You may find that these Since only a few centimetres of the activities are similar to those carried out top layer of soil supports plant growth, by a gardener or even by you when you turning and loosening of soil brings the grow ornamental plants in your house. nutrient-rich soil to the top so that These activities or tasks are referred plants can use these nutrients. Thus, 2 SCIENCE 2024-25 turning and loosening of soil is very Plough : This is being used since important for cultivation of crops. ancient times for tilling the soil, adding The process of loosening and turning fertilisers to the crop, removing the weeds of the soil is called tilling or ploughing. and turning the soil. This is made of This is done by using a plough. Ploughs wood and is drawn by a pair of bulls or are made of wood or iron. If the soil is other animals (horses and camels). It very dry, it may need watering before contains a strong triangular iron strip ploughing. The ploughed field may have called ploughshare. The main part of the big clumps of soil called crumbs. It is plough is a long log of wood which is necessary to break these crumbs. called a ploughshaft. There is a handle Levelling the field is beneficial for at one end of the shaft. The other end is sowing as well as for irrigation. Levelling attached to a beam which is placed on of soil is done with the help of a leveller. the bulls’ necks. One pair of bulls and a Sometimes, manure is added to the man can easily operate the plough soil before tilling. This helps in proper [Fig. 1.1 (a)]. mixing of manure with soil. The soil is The indigenous wooden plough is moistened before sowing. increasingly being replaced by iron Agricultural Implements ploughs nowadays. Before sowing the seeds, it is necessary to Hoe : It is a simple tool which is used break soil clumps to get better yield. This for removing weeds and for loosening is done with the help of various tools. the soil. It has a long rod of wood or The main tools used for this purpose are iron. A strong, broad and bent plate of the plough, hoe and cultivator. iron is fixed to one of its ends and beam ploughshaft ploughshare Fig. 1.1 (a) : The plough CROP PRODUCTION AND MANAGEMENT 3 2024-25 works like a blade. It is pulled by Activity 1.1 animals [Fig. 1.1 (b)]. Take a beaker and fill half of it grip beam with water. Put a handful of wheat handle seeds and stir well. Wait for some time. bent plate Are there seeds which float on rod Fig. 1.1 (b) : A hoe water? Would those be lighter or heavier than those which sink? Why Cultivator : Nowadays ploughing is would they be lighter? Damaged seeds done by tractor-driven cultivator. The become hollow and are thus lighter. use of cultivator saves labour and time. Therefore, they float on water. [Fig. 1.1 (c)]. This is a good method for separating good, healthy seeds from the damaged ones. Before sowing, one of the important tasks is to know about the tools used for sowing seeds [Fig. 1.2 (a), (b)]. Traditional tool : The tool used traditionally for sowing seeds is shaped like a funnel [Fig. 1.2 (a)]. The Fig. 1.1 (c) : Cultivator driven by a tractor seeds are filled into the funnel, passed down through two or three 1.4 Sowing pipes having sharp ends. These Sowing is an important part of crop ends pierce into the soil and place production. Before sowing, good quality, seeds there. clean and healthy seeds of a good variety—are selected. Farmers prefer to use seeds which give high yield. Selection of Seeds One day I saw my mother put some gram seeds in a vessel and pour some water on them. After a few minutes some seeds started to float on top. I wonder why some seeds float on water! Fig. 1.2 (a) : Traditional method of sowing 4 SCIENCE 2024-25  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 The substances which are added to the soil in the form of nutrients for the healthy growth of plants are called manure and fertilisers. Fig. 1.2 (b) : A seed drill Seed drill : Nowadays the seed drill [Fig. I saw a healthy crop growing 1.2 (b)] is used for sowing with the help in a farm. In the neighbouring of tractors. This sows the seeds farm, the plants were weak. uniformly at equal distance and depth. Why do some plants grow It ensures that seeds get covered by the better than others? soil after sowing. This protects seeds from being eaten by birds. Sowing by Soil supplies mineral nutrients to the using a seed drill saves time and labour. crop plants. These nutrients are essential for the growth of plants. In certain areas, farmers grow crop after There is a nursery near my crop in the same field. The field is never school. I found that little left uncultivated or fallow. Imagine what plants were kept in small happens to the nutrients? bags. Why are they Continuous cultivation of crops kept like this? 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 Seeds of a few plants such as paddy are first manuring. Improper or insufficient grown in a nursery. When manuring results in weak plants. they grow into seedlings, Manure is an organic substance they are transplanted to obtained from the decomposition of the field manually. Some plant or animal wastes. Farmers dump forest plants and flowering plant and animal waste in pits at open plants are also grown in places and allow it to decompose. The the nursery. decomposition is caused by some microorganisms. The decomposed Appropriate distance between the matter is used as organic manure. seeds is necessary to avoid overcrowding You have already learnt about of plants. This allows plants to get vermicomposting in Class VI. CROP PRODUCTION AND MANAGEMENT 5 2024-25 Activity 1.2 better growth of plants? In which glass was the growth fastest? Take moong or gram seeds and Fertilisers are chemicals which are germinate them. Select three equal rich in a particular nutrient. How are sized seedlings. Take three empty they different from manure? Fertilisers glasses or similar vessels. Mark them are produced in factories. Some A, B and C. To glass A add little amount of soil mixed with a little cow examples of fertilisers are— urea, dung manure. In glass B put the ammonium sulphate, super same amount of soil mixed with a phosphate, potash, NPK (Nitrogen, little urea. Take the same amount Phosphorus, Potassium). of soil in glass C without adding The use of fertilisers has helped anything [Fig. 1.3(a)]. Now pour the farmers to get better yield of crops same amount of water in each glass such as wheat, paddy and maize. But and plant the seedlings in them. excessive use of fertilisers has made Keep them in a safe place and water the soil less fertile. Fertilisers have also them daily. After 7 to 10 days become a source of water pollution. observe their growth [Fig. 1.3(b)]. Therefore, in order to maintain the fertility of the soil, we have to substitute fertilisers with organic manure or leave the field uncultivated (fallow) in between two crops. The use of manure improves soil texture as well as its water retaining capacity. It replenishes the soil with nutrients. Another method of replenishing Fig. 1.3 (a) : Preparation of the experiment the soil with nutrients is through crop rotation. This can be done by growing different crops alternately. Earlier, 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. Farmers are being encouraged to adopt this practice. In the previous classes, you have Fig. 1.3 (b) : Growing seedlings with manure and fertiliser learnt about Rhizobium bacteria. These are present in the nodules of Did plants in all the glasses grow at roots of leguminous plants. They fix the same pace? Which glass showed atmospheric nitrogen. 6 SCIENCE 2024-25  Table 1.1 : Differences between Fertiliser and Manure S. No. Fertiliser Manure 1. Fertiliser is a man-made Manure is a natural substance obtained inorganic salt. by the decomposition of cattle dung and plant residues. 2. Fertiliser is prepared in Manure can be prepared in the fields. factories. 3. Fertiliser does not provide Manure provides a lot of humus to the soil. any humus to the soil. 4. Fertilisers are very rich in Manure is relatively less rich in plant plant nutrients like nitrogen, nutrients. phosphorus and potassium. Table 1.1 gives the differences protects the crop from both frost and between a fertiliser and manure. hot air currents. To maintain the moisture of the soil for healthy crop Advantages of Manure : The organic growth, fields have to be watered manure is considered better than regularly. fertilisers. This is because The supply of water to crops at l it enhances the water holding regular intervals is called irrigation. The capacity of the soil. time and frequency of irrigation varies l it makes the soil porous due to which from crop to crop, soil to soil and season exchange of gases becomes easy. to season. In summer, the frequency of l it increases the number of friendly watering is higher. Why is it so? Could microbes. it be due to the increased rate of l it improves the texture of the soil. evaporation of water from the soil and the leaves? 1.6 Irrigation All living beings need water to live. Water is important for proper growth I am very careful this and development. Water is absorbed by year about watering the plant roots. Along with water, the plants. Last minerals and fertilisers are also summer my plants absorbed. Plants contain nearly 90% dried up and died. water. Water is essential because germination of seeds does not take place Sources of irrigation : The sources of under dry conditions. Nutrients water for irrigation are— wells, dissolved in water are transported to tubewells, ponds, lakes, rivers, dams each part of the plant. Water also and canals. CROP PRODUCTION AND MANAGEMENT 7 2024-25  Traditional Methods of Irrigation The water available in wells, lakes and canals is lifted up by different methods in different regions, for taking it to the fields. Cattle or human labour is used in these methods. So these methods are cheaper, but less efficient. The various traditional ways are: (i) moat (pulley -system) (ii) chain pump Fig. 1.4 (a) : Moat Fig. 1.4 (b) : Chain pump Fig. 1.4 (c) : Dhekli (iii) dhekli, and (iv) rahat (Lever system) [Figs. 1.4 (a)- (d)]. Pumps are commonly used for lifting water. Diesel, biogas, electricity and solar energy is used to run these pumps. Fig. 1.4 (d) : Rahat 8 SCIENCE 2024-25 Modern Methods of Irrigation Modern methods of irrigation help us to use water economically. The main methods used are as follows: (i) 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 Fig. 1.5 (a) : Sprinkler system at regular intervals. When water is allowed to flow through the main pipe under pressure (ii) Drip system : In this system, the with the help of a pump, it escapes from water falls drop by drop directly near the rotating nozzles. It gets sprinkled the roots. So it is called drip system. It on the crop as if it is raining. is the best technique for watering fruit Sprinkler is very useful for lawns, coffee plants, gardens and trees [Fig. 1.5(b)]. plantation and several other crops Water is not wasted at all. It is a boon in [Fig. 1.5 (a)]. regions where availability of water is poor. Fig. 1.5 (b) : Drip System CROP PRODUCTION AND MANAGEMENT 9 2024-25 1.7 Protection from Weeds Boojho and Paheli went to a nearby wheat field and saw that there were some other plants in the field, growing along with wheat plants. Have these other plants been planted purposely? In a field many other undesirable plants may grow naturally along with Fig. 1.6 : Spraying weedicide the crop. These undesirable plants are called weeds. The removal of weeds is called weeding. Weeding is necessary since Do weedicides have any weeds compete with the crop plants for effect on the person handling the weedicide sprayer? water, nutrients, space and light. Thus, they affect the growth of the crop. Some As already mentioned, the weedicides weeds interfere even in harvesting and are sprayed during the vegetative growth may be poisonous for animals and of weeds before flowering and seed human beings. formation. Spraying of weedicides may Farmers adopt many ways to remove affect the health of farmers. So they weeds and control their growth. Tilling should use these chemicals very carefully. before sowing of crops helps in They should cover their nose and mouth uprooting and killing of weeds, which with a piece of cloth during spraying of may then dry up and get mixed with these chemicals. the soil. The best time for the removal of weeds is before they produce flowers 1.8 Harvesting and seeds. The manual removal includes physical removal of weeds by uprooting Harvesting of a crop is an important or cutting them close to the ground, task. The cutting of crop after it is from time to time. This is done with the mature is called harvesting. In help of a khurpi. A seed drill [Fig. 1.2(b)] harvesting, crops are pulled out or cut is also used to uproot weeds. close to the ground. It usually takes 3 Weeds are also controlled by using to 4 months for a cereal crop to mature. certain chemicals, called weedicides, Harvesting in our like 2,4-D. These are sprayed in the country is either done fields to kill the weeds. They do not manually by sickle damage the crops. The weedicides are (Fig. 1.7) or by a machine diluted with water to the extent required called harvester. In the and sprayed in the fields with a sprayer. harvested crop, the grain Fig. 1.7 : (Fig. 1.6). seeds need to be separated Sickle 10 SCIENCE 2024-25 from the chaff. This process is called Harvest Festivals threshing. This is carried out with the help of a machine called ‘combine’ which After three or four months of hard work there comes the day of the is in fact a harvester as well as a thresher harvest. The sight of golden fields (Fig. 1.8). of standing crop, laden with grain, fills the hearts of farmers with joy a n d a s e n s e o f w e l l -b e i n g. T h e efforts of the past season have borne fruit and it is time to relax and enjoy a little. 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 h a r v e s t s e a s o n are P o n g a l , Baisakhi, Holi, Diwali, Nabanya Fig. 1.8 : Combine and Bihu. 1.9 Storage After harvesting, sometimes Storage of produce is an important task. stubs are left in the field, which are burnt by farmers. Paheli is If the harvested grains are to be kept worried. She knows that it for longer time, they should be safe causes pollution. It may also from moisture, insects, rats and catch fire and damage the crops microorganisms. Harvested grains have lying in the fields. more moisture. If freshly harvested grains (seeds) are stored without drying, Farmers with small holdings of land they may get spoilt or attacked by do the separation of grain and chaff by organisms, making them unfit for use winnowing (Fig. 1.9). You have already studied this in Class VI. or for germination. 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. I saw my mother putting some dried neem leaves in an iron drum containing wheat. I wonder why? Fig. 1.9 : Winnowing machine CROP PRODUCTION AND MANAGEMENT 11 2024-25  Fig. 1.10 (a) : Silos for storage of grains 1.10 Food from Animals Activity 1.3 Make the following Table in your note book and complete it. S.No. Food Sources 1. Milk Cow, Buffalo, She- goat, She-camel... 2. 3. 4. After completing this Table, you must 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 Fig. 1.10 (b) : Storage of grains in part of their diet. In the previous classes gunny bags in granaries you have learnt about the food that we obtain from plants. We have just seen Farmers store grains in jute bags or that the process of crop production metallic bins. However, large scale involves a number of steps like selection storage of grains is done in silos and of seeds, sowing, etc. Similarly, animals granaries to protect them from pests reared at home or in farms, have to be like rats and insects [Fig. 1.10 (a) provided with proper food, shelter and and (b)]. care. When this is done on a large scale, Dried neem leaves are used for it is called animal husbandry. storing food grains at home. For storing large quantities of grains in big godowns, specific chemical treatments Fish is good for health. are required to protect them from pests We get cod liver oil from fish and microorganisms. which is rich in vitamin D. 12 SCIENCE 2024-25 KEYWORDS WHAT Y WHAT OU HA YOU VE LEARNT HAVE AGRICULTURAL Ü In order to provide food to our growing PRACTICES population, we need to adopt certain agricultural practices. ANIMAL HUSBANDRY Ü Same kind of plants cultivated at a place CROP constitute a crop. Ü In India, crops can be broadly categorised into FERTILISER two types based on seasons - rabi and kharif GRANARIES crops. Ü It is necessary to prepare soil by tilling and HARVESTING levelling. Ploughs and levellers are used for this purpose. IRRIGATION Ü Sowing of seeds at appropriate depths and KHARIF distances gives good yield. Good variety of seeds are sown after selection of healthy seeds. MANURE Sowing is done by seed drills. Ü Soil needs replenishment and enrichment PLOUGH through the use of organic manure and RABI fertilisers. Use of chemical fertilisers has increased tremendously with the introduction SEEDS of new crop varieties. Ü Supply of water to crops at appropriate SILO intervals is called irrigation. SOWING Ü Weeding involves removal of unwanted and uncultivated plants called weeds. STORAGE Ü Harvesting is the cutting of the mature crop manually or by machines. THRESHING Ü Separation of the grains from the chaff is called WEEDS threshing. Ü Proper storage of grains is necessary to protect WEEDICIDE them from pests and microorganisms. Ü Food is also obtained from animals for which WINNOWING animals are reared. This is called animal husbandry. Exercises 1. Select the correct word from the following list and fill in the blanks. float, water, crop, nutrients, preparation (a) The same kind of plants grown and cultivated on a large scale at a place is called _____________. (b) The first step before growing crops is _____________ of the soil. CROP PRODUCTION AND MANAGEMENT 13 2024-25  (c) Damaged seeds would _____________ on top of water. EXERCISES (d) For growing a crop, sufficient sunlight and _____________ and _____________ from the soil are essential. 2. Match items in column A with those in column B. A B (i) Kharif crops (a) Food for cattle (ii) Rabi crops (b) Urea and super phosphate (iii) Chemical fertilisers (c) Animal excreta, cow dung urine and plant waste (iv) Organic manure (d) Wheat, gram, pea (e) Paddy and maize 3. Give two examples of each. (a) Kharif crop (b) Rabi crop 4. Write a paragraph in your own words on each of the following. (a) Preparation of soil (b) Sowing (c) Weeding (d) Threshing 5. Explain how fertilisers are different from manure. 6. What is irrigation? Describe two methods of irrigation which conserve water. 7. If wheat is sown in the kharif season, what would happen? Discuss. 8. Explain how soil gets affected by the continuous plantation of crops in a field. 9. What are weeds? How can we control them? 10. Arrange the following boxes in proper order to make a flow chart of sugarcane crop production. Sending crop to Irrigation Harvesting Sowing sugar factory 1 2 3 4 Preparation of Ploughing the Manuring soil field 5 6 7 14 SCIENCE 2024-25  11. Complete the following word puzzle with the help of clues given below. EXERCISES Down 1. Providing water to the crops. 2. Keeping crop grains for a long time under proper conditions. 5. Certain plants of the same kind grown on a large scale. Across 3. A machine used for cutting the matured crop. 4. A rabi crop that is also one of the pulses. 6. A process of separating the grain from chaff. Extended Learning — Activities and Projects 1. Sow some seeds in the soil and arrange to water them by drip irrigation. Observe daily. (i) Do you think it can save water? (ii) Note the changes in the seed. 2. Collect different types of seeds and put them in small bags. Label them. 3. Collect pictures of some other agricultural machines and paste them in a file. Write their names and uses. 4. Project Work Visit a farm, nursery or a garden nearby. Gather information about (i) importance of seed selection. (ii) method of irrigation. CROP PRODUCTION AND MANAGEMENT 15 2024-25  (iii) effect of extreme cold and extreme hot weather on the plants. (iv) effect of continuous rain on the plants. (v) fertilisers/manure used. An Example for Field Trip Work Himanshu and his friends were very anxious and curious to go to Thikri village. They went to Shri Jiwan Patel’s farmhouse. They had taken bags to collect some seeds and other things. Himanshu : Sir namaskar, I am Himanshu. Here are my friends Mohan, David and Sabiha. We want some information about crops. Please guide us. Shri Patel : Namaskar and welcome all of you. What are your queries? Sabiha : When did you start this work and what are the main crops that you grow? Shri Patel : About 75 years ago, my grandfather started this work. The main crops that we grow are wheat, gram, soyabean and moong. David : Sir, can you tell us the difference between traditional and modern agricultural practices? Shri Patel : Earlier we used traditional tools like sickle, bullock plough, trowel, etc., and depended on rain water for irrigation. But now we use modern methods of irrigation. We use implements like tractors, cultivators, seed drill and harvester. We get good quality seeds. We carry out soil testing and use manure and fertilisers. New information about agriculture is obtained through radio, T.V. and other sources. As a result we are able to get good crops on a large scale. This year we got 9 to 11 quintals of gram crop/acre and 20 to 25 quintals of wheat/acre. In my opinion awareness of new technology is important for better crop yield. Mohan : Sabiha, come here and see some earthworms. Are they helpful to the farmers? Sabiha : Oh Mohan! we learnt about it in Class VI. Shri Patel : Earthworms turn the soil and loosen it for proper aeration, so they help the farmer. David : Can we have some seeds of the crops you grow here? [They put some seeds, fertilisers and soil sample in the bags.] Himanshu : Sir, we are thankful to you for making this visit pleasant and for providing useful information. 16 SCIENCE 2024-25