Crop Production and Management PDF

# Crop Production and Management ## Learning Objectives By the end of the lesson, you will be able to: - Define agriculture, field, and crop plants. - Explain the different agricultural practices. - Describe animal husbandry. ## Agriculture Food is essential for all living organisms. Green p...

# Crop Production and Management ## Learning Objectives By the end of the lesson, you will be able to: - Define agriculture, field, and crop plants. - Explain the different agricultural practices. - Describe animal husbandry. ## Agriculture Food is essential for all living organisms. Green plants, as you have already learned, make their own food. However, animals, including humans, cannot synthesize food. They feed on either plants or other animals. In all cases, the food for animals comes directly or indirectly from plants. The science that deals with the raising of plants and the rearing of animals for human use is called agriculture. In a broad sense, agriculture includes: * **Soil management** - the preparation of soil * **Crop farming** - the growing and harvesting of crops * **Horticulture** - the growing and harvesting of fruits, vegetables, flowers, and decorative plants * **Animal husbandry** - the breeding and raising of livestock, including poultry ### How Did It All Start? For thousands of years, humans were wanderers who kept moving from place to place in search of food and shelter. Then, about 10,000 years ago, humans started growing plants such as wheat and barley. This marked the first great change in the human lifestyle. The spread of agriculture meant that humans no longer had to wander around in search of food. They could settle down in communities. They also started domesticating animals for food and other purposes. Agriculture thus made it possible for a larger population to be sustained in one place. ### Modern Agriculture With an increase in population, humans had to learn to grow better quality crops and increase the yield. Over the years, humans learnt more and more about crops and the conditions that were required for the healthy growth of crops. For example, rice grows well in clayey soil and needs a lot of water, whereas wheat grows well in alluvial soil and needs less water. Humans realized how important water was for the healthy growth of plants. They therefore built dams and canals to help irrigate fields. Humans also made tools such as the sickle, axe, and plough to help them farm. They developed newer techniques of preparing the soil for cultivation. Machines such as tractors, combine harvesters, and threshers have improved the efficiency of agricultural processes and contributed to increased output. Another area that has seen tremendous progress in the past few decades is the development of new hardy, pest-resistant, high-yielding varieties of plants by scientists. For example, several high-yielding varieties of wheat have been developed in India. Fertilizers and pesticides are also now available to farmers in plenty, ensuring proper nutrition and protection of crops. Added to all this, a good knowledge of soil types, requirements of crops, and climate helps the farmer. ### Crops and Their Classification The land where plants are cultivated is known as a field. Plants grown in large quantities in a field are known as crop plants, or crops. The first cultivated crops were cereals like wheat, barley, rice, and corn. Their seeds are rich in carbohydrates. Cereals, therefore, form the staple diet almost everywhere in the world. Cereals also contain proteins, vitamins, minerals, and fiber. **Crops based on products obtained** The products obtained from crops are called produce. Some common crops are listed in Table 1.1. | Table 1.1 Some common crops | |----------------------------------| | Cereals | Wheat, rice, barley, corn, ragi | | Pulses | Gram, peas, beans | | Root and tuber crops | Sweet potato, tapioca, potato | | Oilseed crops | Mustard, groundnut, sunflower | | Sugar crops | Sugarcane, sugar beet | | Plantation crops | Coffee, tea, rubber, coconut | | Fibre crops | Jute, cotton | **Crops based on season** Most crops grow well only in a particular season. Based on the season, crops are divided into two types - summer crops called kharif crops and winter crops called rabi crops. **Kharif crops** They are grown in the summer between June and July, and harvested by September or October. Rice, groundnut, maize, cotton, and pulses are some common kharif crops. **Rabi crops** They are grown in the winter between October and November, and harvested by March or April. Wheat, barley, mustard, potato, and peas are some common rabi crops. **Crops based on life cycle** Based on the time taken to complete their life cycle, crops are divided into annuals, biennials, and perennials. * **Annuals** - Crops that take one growing season to complete their life cycle are called annuals. Some examples of annuals are wheat, rice, and corn. * **Biennials** - These crops take two growing seasons to complete their life cycle. During the first year, the plants store food in their roots. The energy in this food is then used by the plant to produce fruits and seeds in the second year. Carrots are biennials. * **Perennials** - These plants live for more than two growing seasons and continue to produce seeds. The apple and banana are some examples of perennials. ## Agricultural Practices With the recent progress made in agriculture, farmers have learned to cultivate crops in a systematic way. The tasks that a farmer carries out to cultivate crops are called agricultural practices. They are listed below: * The preparation of soil * The selection and sowing of seeds * Manuring * Irrigation * Weeding * The protection of crops * Harvesting * Threshing and winnowing * Storage Let us study each practice in detail. ### The Preparation of Soil Soil is the natural medium in which plants grow. It is prepared for cultivation by ploughing and leveling. **Ploughing** Ploughing or tilling is done with a plough. The plough helps to turn over soil and to make furrows or grooves to plant seeds. A plough can be pulled by bullocks or by animals like horses. Nowadays, ploughing is done with a tractor-driven cultivator, which saves time and labour. Ploughing loosens soil. Loosening soil: * Allows roots to breathe easily. * Helps roots to grow deeper into the soil. * Enables fertilizers to mix uniformly with the soil. * Encourages organisms such as earthworms, millipedes, bacteria, and fungi to increase in number. These organisms are important for the soil. Earthworms are known as friends of the farmer, as they ensure aeration of the soil. Plant and animal wastes and decayed dead organisms also help in manuring the soil. **Levelling** After ploughing, the field is levelled using a wooden or an iron leveller. Leveling the field prevents the loose soil from being eroded by wind or water. It also ensures uniform irrigation. ### The Selection and Sowing of Seeds Seeds selected for sowing (planting) should be of good quality, healthy, viable (able to grow into young plants), and free of infections. Adequate care must be taken while sowing seeds. * Seeds must be planted at the correct depth in the soil. If they are planted too deep, they will not be able to respire, and the shoot will struggle to push through the soil. If they are on the surface, they will be eaten by birds. * The soil should have the right amount of water for the seeds to germinate. Seeds will not germinate in dry soil. However, seeds will also not germinate if there is excess water in the soil. * Seeds should be planted at the right distance from each other. If they are planted too close, they will not get enough sunlight, water, and nutrients. Planting them too far apart results in wastage of field space. Seeds are sown manually by broadcasting or by using seed drills * **Broadcasting** is the scattering of seeds over the soil surface by hand. * **Seed drills** have a funnel-shaped opening leading to long tubes. They are tied to the back of a plough and seeds are put into the funnel. The drill deposits the seeds at regular intervals. The use of seed drills ensures a more accurate sowing of seeds than broadcasting. Sometimes, for tomato, onion, chilli, rice, and brinjal plants, the seeds are planted in a seed bed, called a nursery. After they germinate and grow to a certain height, they are shifted to the field. Growing seeds in a nursery and shifting seedlings to the field is called transplantation. This helps the farmer to select healthy seedlings and space them properly while planting them. Transplantation also results in increased crop yield. ### Manuring Plants require certain minerals, called plant nutrients, for proper growth. There are at least 16 nutrients required by plants. These nutrients can be broadly classified into two groups. * **Macronutrients** - Elements such as carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur are called macronutrients as they are required in large amounts. * **Micronutrients** - Elements such as iron, manganese, copper, boron, molybdenum, zinc, and chlorine are called micronutrients as they are required in smaller quantities. Plants obtain carbon from carbon dioxide in air, oxygen from air and water, and hydrogen from water. The remaining nutrients are obtained from the soil. ### Methods of Cultivation When the land is cultivated for a long time, the nutrients in the soil are used up. There are several methods of replenishing the lost nutrients. * **Fallowing** - An old method of replenishing lost nutrients is to let the land remain fallow, that is, to leave it uncultivated for a season. However, with the increase in population and the high demand for food grains, this method is no longer followed. * **Crop rotation** - Each crop uses more of some elements and less of others. Alternate crops are, therefore, grown, so that the land is not drained of any one nutrient. This is called crop rotation. For example, after a season of wheat or rice, which uses up large amounts of nitrogen from the soil, a legume can be grown because it fixes nitrogen and replenishes the soil with usable nitrogen. The soil is then ready for the next wheat or rice crop. * **Multiple cropping** - This is a method in which two or more crops are grown together in the same field. If the crops are properly chosen, the products and waste materials of one crop help in the growth of the other, and vice versa. This improves the fertility of the soil and increases the yield. Cotton and groundnut crops are often grown together for this reason. However, these methods alone are not enough to maintain the fertility of the soil. Farmers also have to add manures or fertilizers from time to time. Soil fertility can be increased in two ways. * **Organic method** - This involves the use of organic manures. * **Inorganic method** - This involves the use of chemical fertilizers made by humans. **Manures** Manures are organic matter composed of dead plants and animal waste. Compost is manure made by the decomposition of plant and animal waste. The waste is buried in pits, where bacteria and fungi act on it and decompose it. Manures play an important role in improving soil fertility. They are rich in matter that helps to build soil. They tend to break down slowly in the soil, so they are quite long lasting. This means that they provide plants with nutrients (including micronutrients) over a long period of time. Composts are usually safe to apply directly to soil. Since the nutrients are not concentrated, there is little danger of scorching (chemically burning) the plants. However, manures provide low quantities of nutrients and release them slowly. **Chemical fertilizers** Chemical fertilizers are substances that contain inorganic salts, that is, minerals needed for plant growth. Fertilizers supply mainly nitrogen (N), phosphorus (P), and potassium (K). They are available either as 'compound' fertilizers containing a mix of the three major nutrients in varying proportions, as in the NPK fertilizer, or as fertilizers with one major nutrient, like potash and super phosphate, which are rich in potassium and phosphorus, respectively. Fertilizers dissolve in water easily and can be used to quickly provide plants with the minerals they need. However, the effect of fertilizers lasts only for a short time. They easily leach out of soil as water drains away. Since fertilizers are available in concentrated form, they need to be measured and applied to the soil carefully to avoid damaging or killing crops. If not properly selected, fertilizers can harm soil by changing soil chemistry. For example, the use of sodium nitrate increases the alkalinity of soil, while the addition of ammonium sulphate raises the acidity of soil. Fertilizers can also damage soil by suppressing the activities of bacteria that fix nitrogen. Farmers often use a mixture of manures and fertilizers to get the advantages of both. ### Irrigation Some parts of the world do not receive enough rainfall for crops to grow well. Even where the average rainfall is high, crops may not receive enough rain when they need it. In such cases, yield can be increased by watering the crops. Irrigation is the artificial supply of water to crops when needed. Water needed for irrigation comes from rivers, reservoirs, lakes, ponds, wells and tube wells. The water is led along long canals or pumped into fields through pipes using electric or diesel pumps. The duration and frequency of irrigation depend on the type of crop, the type of soil and the season. For example, rice plants are transplanted into standing water as they need continuous irrigation. Wheat requires water during different stages of its growth - when it has just branched, at flowering time and later during grain formation. Irrigation is very important to the farmers of our country, as water is not freely available in all places when needed. In India, only about one-third of cultivable land is under irrigation, while the remaining is dependent on rain. Irrigated fields should be provided with adequate drainage; if not, waterlogging can take place. Waterlogging prevents the proper growth of crops by reducing air supply to the roots and also increasing the salt content of the soil. ### Traditional Methods of Irrigation Human- and animal-powered water-lifting devices have been used traditionally in irrigation for thousands of years in India. * **The swing basket method** is used to lift surface water with the help of bamboo baskets or leather and iron sheets. * **The Persian wheel (rahat) method** involves bullocks moving in a circle to turn a drum and raise water. * **The rope and bucket with pulley system (moat) method** involves animals or humans pulling a rope attached to a bucket passed over a pulley, to collect water from a well. ### Modern Methods of Irrigation **Sprinkler irrigation** is a modern method of irrigation in which water is sprayed to copy natural rainfall. In this type of irrigation. water is distributed through a system of pipes, usually by pumping. The water is then sprayed into the air through rotating sprinklers so that it breaks up into small water droplets that fall to the ground. This type of irrigation ensures a uniform supply of water to crops. This is an advantage of sprinkler irrigation. **Drip irrigation**, also known as trickle irrigation, is the most expensive method of irrigation. However, it is the most efficient method of using water. In this type of irrigation, water is transported through a network of pipes and valves to the plants. The water is either allowed to drip slowly onto the soil near the roots, or is released slowly just under the surface of the soil. Drip irrigation is an effective method of irrigating fruit and vegetable plants. ### Weeding Weeding is the removal of unwanted plants (weeds) that grow with crops. Weeds grow fast and compete with crops for water, minerals, and sunlight. They also spread pests. Weeds sometimes produce poisonous substances, thus reducing the yield of crops. So, it is necessary to remove them from time to time. Some examples of common weeds are Parthenium, Amaranthus (chaulai), Chenopodium (bathua), grass and wild oats. Weeding can be done manually by removing the weeds by hand or by using a trowel or a harrow. Weeding can also be done by spraying weedicides (also called herbicides), which destroy the weeds but not the crops. Some common weedicides are Siniazine and Picloram. Weedicides must be used with care, as they are poisonous to humans. Therefore, grain and other crop produce must be washed thoroughly before being consumed. ### The Protection of Crops Crops are eaten or damaged by pests like rodents (rats) and insects (locusts, termites and weevils). Locusts fly in swarms and eat leaves. They destroy vast areas of sugarcane and wheat plantations. Other insects, such as stem borers, bore holes in the stem, while termites eat roots. One-tenth of the global crop production is destroyed by pests every year. Crops are also attacked by microorganisms such as bacteria, fungi, and viruses, which reduce yield by causing several diseases. For example, fungi cause rust and smut in wheat, and blight in potatoes. Both bacteria and fungi cause a disease called wilt in plants, which blocks the tissues that transport water (xylem). Consequently, the plant dies due to lack of water. Pests and microorganisms can be eliminated by using chemical control and biological control. **Chemical control** Chemical control involves spraying the soil with chemical substances called pesticides that kill the pests. Insecticides, fungicides, and rodenticides are types of pesticides. * **Insecticides** are used to destroy insects. Carbaryl and malathion are examples. * **Fungicides** are used to destroy fungi. Sulphur and many copper salts are examples. * **Rodenticides** are used against rodents. Zinc phosphide and Atrazine are examples. Spraying can be done by hand-operated machines or by low-flying aircraft. **Advantages of using pesticides** * They kill pests quickly. * They are easy to store and use. * A large variety of chemicals are available that can eliminate most pests. **Disadvantages of using pesticides** * Pests can develop resistance to a particular pesticide. * Pesticides can affect wildlife when sprayed in a particular area. * Pesticides can seep into the soil and drain into rivers and lakes, causing pollution. * They can enter food chains and build up from one feeding level to the next. * Being toxic, they can affect the health of humans. Since they can enter our bodies through fruits and vegetables, these should be washed thoroughly before being consumed. **Biological control** Biological control can be a powerful method of controlling pests. It involves the deliberate use of one organism to regulate the population of pests. But there are disadvantages to this method. Biological control agents may negatively affect native plant and animal species directly or indirectly. ### Harvesting Harvesting is the cutting and gathering of mature crop from fields. Fruits and vegetables can be harvested manually or mechanically, and either sold immediately or stored in a cold storage unit for future use. In small farms, grains are harvested manually using a sickle. In large farms, it is done using expensive and sophisticated farm machinery like the combine harvester, which helps with both harvesting and threshing. ### Threshing and Winnowing Threshing is the process of just loosening the edible part of grain from the surrounding scaly, inedible chaff. One method of threshing involves beating the grain on the threshing floor. Another traditional method is to place the harvested material on a hard surface and make farm animals such as cattle or donkeys walk in circles on it. However, in developed areas, threshing is now mostly done with a combine harvester. Wind winnowing is a method of separating grain from chaff by throwing the mixture into the air with a winnowing fan. The chaff, being lighter, is blown away by the wind, while the heavier grains fall down for recovery. Insect pests can also be removed from stored grain with this method. ### Storage Food products obtained from crops have to be preserved and stored for future use. Proper storage ensures that food is free from infestation by fungi and insects. The produce can then be made available throughout the year and transported to different places easily. **Methods used for storage** Grains are dried in the sun and then packed in bags or bins before being stored in granaries. This helps to reduce, to some extent, the growth of microorganisms and damage caused by rodents. To keep the granaries free of pests, various pesticides are sprayed in them. **Grain silos (Fig. 1.15)** are specially designed large containers for bulk storage of grains. Different stocks of grains are stored at different levels. The grain silos are designed such that the temperature can be controlled and the grain can be inspected, fumigated, and protected from rodents, birds and pests. The grain can be collected using chutes or slides at different levels. A shortage of rain in a particular year can lead to a shortage of grains. Therefore, some stock of grain is kept in reserve to compensate for a shortage. This is known as buffer stock. ## Animal Husbandry Humans started domesticating animals when they stopped leading a nomadic life and started settling down in communities (around 10,000 BCE). Economically useful farm animals are referred to as livestock. The breeding, feeding, and caring of livestock for food and other purposes is called animal husbandry. Many farmers in India depend on animal husbandry for their livelihood. In addition to supplying milk, meet, eggs, and hides, animals, mainly bullocks, are very important as draught animals (used for ploughing and carrying loads). ### Useful Animals Humans are dependent on animals in innumerable ways. Animals are a source of food (meat, milk, eggs) and clothing (wool, leather). They are useful in transportation and also provide company as pets. Animal products are obtained by different methods like dairy farming, livestock farming, poultry farming (raising birds such as hens and ducks), sericulture (raising silkworms), apiculture (raising bees), and pisciculture (raising fish). The animals domesticated by humans can be divided into the following categories, based on the products we get from them. * **Milk-yielding animals or dairy animals**, like the cow, buffalo, and goat * **Meat-yielding animals**, like the pig, sheep, goat, cattle, fish, and poultry * **Egg-yielding animals**, like poultry (hens, ducks, and so on). * **Wool- and skin-yielding animals**, like the sheep, goat, cattle, and camel. * **Honey-yielding animals** like the bee, **silk-yielding animals** like the silkworm, and **pearl-yielding animals** like the oyster. * **Draught animals** or animals used for farm work, including the mule, donkey, horse, buffalo, and camel. They are used in transportation, and other farm work such as ploughing and threshing. Livestock should be properly cared for. If they fall ill or are not clean, they may cause diseases in human beings. ## Looking Back Answer the following questions: 1. What are weedicides used for? 2. Give another name for weedicides. 3. Name two insecticides. 4. What are sulfur and copper salts used for in crop production? 5. What is zinc phosphide used for? 6. Name the method which makes use of another organism to kill a pest. 7. How is chaff separated from grains? 8. What are economically useful domesticated animals known as? ## Assess Yourself Mark ✓ if you have understood the concept. * The science that deals with the raising of plants and the rearing of animals for human use is called agriculture. * Plants grown in large quantities in a field are known as crop plants or crops. * The first cultivated crops were cereals such as wheat, barley, rice, and corn. * Broadcasting is the scattering of seeds over the soil surface by hand. * Irrigation is the artificial supply of water to farms when needed. * Harvesting is the cutting and gathering of mature crop from fields. * Threshing is the process of loosening the edible part of grain from the surrounding scaly, inedible chaff. * Wind winnowing is a method of separating grain from chaff by throwing the mixture into the air with a winnowing fan. * Grain silos are specially designed large containers for the bulk storage of grains. * The breeding, feeding, and caring of livestock for food and other purposes is called animal husbandry.