Improvement in Food Resources

 3.1 INTRODUCTION

You must have heard people discussing about the requirement to improve ways of crop production. Do you know why we require devising methods to improve production of crops to obtain a better yield? This is because our country is over-populated and supports around one billion people. Therefore, in order to feed such a large population, we have to improve the methods of crop production to obtain a better crop yield.

TYPES OF CROPS

Crops are plants which are cultivated by humans for food, folder, fiber, flowers, timber, etc. There are about 2000 plant species which are cultivated for eating purposes. Following parts of the plants are eaten as food.

1.  Seeds. Not all seeds of plants are edible. For example, large seeds such as those from a lemon pose a choking hazard, whereas seeds from apple and cherries contain poison cyanide. Edible seeds include cereals, pulses, oil seeds and nuts (dry fruits).

(a) Cereals. They include crops such as wheat, rice, maize, barley, sorghum, etc. They are a rich source of carbohydrates.

(b) Pulses. They include legumes such as a chicken pea gram, (chana), pea (matar), black gram (urad), green gram (moong), pigeon pea (arhar), cow pea (lobia) and lentil (masoor). They are excellent source of proteins.

(c) Oil seed crops. They include cotton seed, niger (Ramtil), safflower, soybean, flax (linseed oil), rapeseed groundnut, sesame, mustard, sunflower, olive, etc. They are source of oil, fats and fatty acids. These seeds are typically high in unsaturated fats and when consumed in moderation is regarded as healthy foods. Coconut oil and palm oil are cheap sources of cooking medium.

Note: Castor oil is not edible oil. It is mainly used as a lubricant or purgative, in the manufacturing of transparent soaps, inks, paints, phenyls, hair fixers, etc.

(d)   Nuts dry fruits. Nuts are rich in proteins and fatty acids, so are considered energetic food items. Examples include almond, walnut, cashew nut, pistachio, fig, raisin (or currant), dried apricot, coconut, peanut, date etc.

2.  Fruits. They include apple, orange, mango, banana, pineapple, guava, papaya, watermelon, muskmelon, pomegranate, pear, peach, apricot, grapes, dates, custard apple, etc., Essentially fruits are ripened ovaries of plants and are a good source of vitamins, minerals, roughage, proteins, carbohydrates and fats.

3. Vegetables. They are the edible parts of the herbaceous plants. They are eaten in raw or cooked form vegetables are of following types:

(a) Roots. Roots of some plants such as carrot, radish, turnip, sweet potato, and beetroot are eaten as vegetables.

(b) Stems. Stems of some plants such as mustard, bamboo, banana, asparagus, etc., are used as vegetables. Certain plants have modified underground stems that are eaten, eg., potato, onion, garlic, ginger, etc., Stems of sugarcane are used for making of cane juice and jaggery.

(c)   Leafy vegetables. They include leaves of spinach, lettuce, cabbage, turnip, radish, mustard, methi, bathua (pigweed) and curry-leaf tree. (d)   Inflorescence vegetables. They include broccoli, cauliflower, etc., of vegetables. Flowers of banana, fennel, gourd and saffron are also good examples of vegetables.

(e)   Fruit vegetables. They include tomato, pumpkin, brinjal (egg plant) jack fruit, bitter gourd, bottle gourd, ridged gourd, cluster bean, cucumber, lady’s finger, pumpkin (sitaphal), capsicum, lablab bean, vegetable sponge (ghia torai), faraz bean, tamarind, carmbola (kamrakh) etc.

4. Species. Certain parts of some plants (eg., leaves, stems, flowers, fruits and seeds) are used to enhance the palatability of food. They include chilly, turmeric, black pepper, cumin, fenugreek, cardamom, fennel, nutmeg, lovage, sesame, cinnamon, dried ginger (sounth), etc., 5. Fodder crops. They provide green fodder to the cattle, e.g., berseem, oat, sudan grass, sorghum etc.

6. Other crops. Crops plants also yield fibres (e.g., cotton) tobacco, tea, coffee, chocolate, peppermint, etc.,

CLASSIFICATION OF CROPS BASED ON SEASONS OF CULTIVATION

Kharif crops: The crops which are grown in the rainy season (or Kharif season) are known as 

Kharif crops. These crops are cultivated between the months of June and October. Examples of Kharif crops include paddy, soya bean, pigeon pea, maize, cotton, green gram, and black gram.

Rabi crops: The crops which are grown in the winter season (or Rabi season) are known as Rabi crops. These crops are cultivated between the months of November and April. Examples of Rabi crops include wheat, gram, peas, mustard, and linseed.

Seasonal cultivation of crops assures a maximum yield. Do you know any other methods of cultivation by which the crop yield can improve? Let us explore.

3.2   IMPROVEMENT IN CROP YIELDS

The following activities can lead to an improvement in crop production: Crop variety improvement

    Crop production improvement

     Crop protection management

These activities can be understood by following practices involved in farming. The practices involved in farming can be divided into the following three stages:

     Choosing appropriate seeds for planting

     Nurturing the crop plant

    Protecting the growing crops and minimizing the loss of harvested plants

3.3 CROP VARIETY of IMPROVEMENT METHODS

A farmer grows two varieties of rice, one which produces nutritionally-rich grains during the monsoon season and the other which produces nutritionally-poor grains in all seasons. He begins to wonder if he could grow nutritionally-rich grains in all seasons. Do you think it is possible? Hybridization is the method by which two characteristics present in different organisms can be brought together into one organism. Therefore, a hybrid plant produced from two varieties will have characteristics from both the parent plants.

Therefore, it will be able to produce nutritionally-rich grains, which can be cultivated throughout the year.

Genes are responsible for the features present in an organism. Therefore, another method to grow plants with the desired characteristics is to incorporate genes responsible for that character into plants. This method will result in the production of genetically modified plants.

Can you tell what other characteristics are desired in plants? India is a country with varied regions. Certain regions are very fertile while others are dry with very low rainfall. Hence, all crop plants cannot grow in all regions.

Therefore, crop plants that produce high yields in all regions with different conditions have to be produced.

Take a handful of beans and sow them in soil. Water the soil regularly and allow the beans to grow. You will observe that all plants do not grow together. Some grow faster while others grow much later. Imagine this problem in a vast farm land. If a farmer sows seeds and they do not grow uniformly, then they would not mature uniformly and he would not be able to harvest the yield at the same time. Therefore, seeds that germinate under similar conditions have to be produced.

FACTORS THAT AFFECT THE GROWTH OF CROP PLANTS

Rainfall: The amount of rainfall affects the crop plants i.e., flood and drought conditions affect the growth of crop plants.

Soil condition: In coastal regions (sometimes in other regions too), soil has a high salt content. Therefore, producing plants, which can resist a high salt content in soil, is beneficial.

The problems caused by non-living factors are termed as abiotic stress. The produced plants, which can resist them, are called abiotic stress resistant plants. Some abiotic stress resistant plants produced are

(i) drought resistant

(ii) salinity resistant

(iii) flood (water-logging) resistant

(iv) heat/cold/frost resistant

Disease: 

Plants are attacked by insects, nematodes, and other disease-causing microbes, which can decrease the yield. Therefore, producing plants, which can resist the attack by pathogens, is beneficial. The problems caused by living factors are termed as biotic stress. The produced plants, which can resist them, are called biotic stress resistant plants.

Biotic stress-resistant plants that are produced are called disease resistant plants.

FACTORS THAT IMPROVE THE YIELD OF CROP PLANTS

Improvements are aimed to maintain the quality of crop plants (nutritional factors).

Improving crop quality is done in the following plants.

Protein quality in pulses

Oil quality in seeds

Preserving quality in fruits to reduce loss by spoilage

CHANGING MATURITY TIME

By growing a plant that grows and yields faster, the crop cycle is reduced to increase profits. This reduces the cost that a farmer incurs during crop production. Uniform maturity allows the farmer to harvest crops together.

OTHER AGRONOMICAL FACTORS

Tall branching plants are beneficial for plants whose leaves are to be utilized (for example, fodder crops that are grown to feed farm animals). Short plants are beneficial in cereals so that nutrition is not consumed by plants to grow taller.

3.4 CROP PRODUCTION MANAGEMENT

In India, as in many other agriculture-based countries, farming ranges from small to very large farms. Different farmers thus have more or less land, money and access to information and technologies. In short, it is the money or financial conditions that allow farmers to take up different farming practices and agricultural technologies. There is a correlation between higher inputs and yields. Thus, the farmer’s purchasing capacity for inputs decides cropping system and production practices. Therefore, production practices can be at different levels. They include ‘no cost’ production, ‘low cost’ production and ‘high cost’ production practices.

3.5 NUTRIENT MANAGEMENT

Observe a plant growing in your garden. What are the sources from which a plant obtains nutrition? A plant is exposed to air. Its roots are present in soil. Water is obtained from soil or provided by us. Therefore, the sources of nutrients for plants are as follows.

(i) Air (ii) Soil (iii)  Water

NUTRIENTS REQUIRED BY PLANTS

In total, there are sixteen nutrients required by plants. Some nutrients are required in small quantities and are called micronutrients. Nutrients required in larger quantities are called macronutrients. Nutrients are essential elements, which are used by plants in large quantities.

The table lists the various nutrients required by plants.

Macronutrient Micronutrient
Phosphorus Magnesium Potassium Nitrogen Calcium Sulphur Molybdenum Manganese Chlorine Copper Boron Zinc Iron

The table below separates the nutrients obtained from different sources.

Source Nutrient
Air Carbon and Oxygen
Water Hydrogen and Oxygen
Soil Macronutrient and Micronutrient

When nutrients are not available to plants, physiological activity (such as growth, reproduction, and vulnerability to diseases) increases. Providing proper quantity of nutrients to plants ensures proper growth. But what are the ways by which nutrients can be added to soil? Soil can be replenished and the lost nutrients can be retrieved by adding manures and fertilizers. Let us learn about them.

MANURE

Collect kitchen waste, plant waste, ash, newspaper, food scraps, etc. Mix them with soil and add some water. Stir and mix the contents regularly. Allow the materials to decompose.

This mixture is rich in organic matter, renders soil fertile, and promotes luscious growth of plants. This mixture is called manure. Therefore, manure is decomposed animal and plant waste. It increases the water-holding capacity of soil.

composition of manure

Manure is a source of many plant nutrients. It is composed of organic matter and minerals. Ammonia, nitrate, organic substances, etc. are predominant organic matters found in manures. Manures are mostly composed of micronutrients such as zinc (Zn), manganese (Mn), copper (Cu), magnesium (Mg), sodium (Na), etc.

Advantages of manures

Manures affect the soil in following three ways:

(i)   Manures enrich the soil with nutrients. They replenish the general deficiency of nutrients in the soil. Since manures contain fewer nutrients they need to be used in large quantities.

(ii) Manures add organic matter (called humus) to the soil which restores the soil texture, for better retention of water and aeration of soil. For example, organic matter present in the manures increases the water holding capacity in sandy and drainage in clayey soil. They also prevent water logging in clay soils.

(iii) The organic matter in manures provided food for the soil organisms, (decomposes such as bacteria, fungi, etc.) which help in providing nutrients to plants.

Thus, organic manures help to improve the physical properties of soil, reduce soil erosion, increase the moisture holding capacity of soil and are low cost nutrient carries. Using biological waste material is a way of re-cycling the farm waste. Manures protect our environment from synthetic chemicals (i.e., fertilizers).

Disadvantages of manures

Manures are bulky with low nutrient content. The nutrients get released slowly, unable to fulfill the high and rapid demand of nutrients required by improved high-yielding hybrid varieties of crops. Being bulky and voluminous, they are inconvenient to handle, store and transport. Moreover, manures are not nutrient specific and hence, are not much useful when a particular nutrient is required in the soil for a particular crop.

Types of manures

1.  Farmyard manure (FYM). FYM is the decomposed mixture of cattle excreta, (dung), urine, litter (i.e., bedding material used in night under cattle) and left over organic matter such as roughage, or fodder. These waste materials are collected daily from the cattle shed and stored in pit for decomposition by the microorganisms (bacteria, fungi, etc). FYM contains nitrogen, phosphorus and potassium. A well decomposed farmyard manure contains about 0.5 percent nitrogen (N), 0.2 percent phosphorus pentaoxide (P2O5) and 0.5 percent potassium monoxide (K2O).

2.  Compost. Compost is prepared from farm and town refuge such as vegetable and animal refuse (e.g., excreta of domestic animals such as cattle, goat, sheep, horse, donkey, camel, dogs, cats, etc.,) faecal matter of human beings, sewage waste, weeds, crop, stubble, straw, rice hulls, forest litter, etc. Compositing is a biological process in which both aerobic (organisms requiring the presence of oxygen for the respiration) and anaerobic (organisms, in which respiration takes place in the absence of oxygen) microorganisms decompose the organic matter. It takes about 3 to 6 months for decomposition of organic refuse. The nutrient contents of town compost are about 1.4 percent nitrogen (N), 1.0 per cent phosphorus pentaoxide (P2O5) and 1.4 percent potassium monoxide (K2O).

FERTILIZERS

Fertilizers provide plant nutrients, commercially manufactured using chemicals. Fertilizers supply nitrogen, phosphorus and potassium (NPK). They are used for good vegetative growth (i.e., growth of leaves, branches and flowers), giving rise to healthy plants. Fertilizers are one of the major components for obtaining higher yields especially in expensive farming practices. Fertilizers contain much higher amount of nutrients in comparison to the manures and are, therefore, used in very small quantities. A complete fertilizer is one which contains all the three critical elements or minerals, nitrogen, phosphorus and (e.g., ammonium sulphate) or organic compounds (e.g., urea). On the basis of the availability of nutrients from them, fertilizers are divided into following four groups:

1. Nitrogen fertilizers. These fertilizers supply the macronutrient. Examples of nitrogenous fertilizers are: (i) Urea, CO(NH2)2; (ii) Ammonium sulphate, (NH4)2SO4; (iii) Calcium ammonium nitrate; (iv) Sodium nitrate, NaNO3; (v) Ammonium nitrate, NH4NO3.

2. Phosphatic fertilizers. They are the source of the macronutrient phosphorus. Examples of phosphatic fertilizers are: (i) Single superphosphate; (ii) Triple super phosphate; (iii)   Dicalcium phosphate.

3.  Potassic fertilizers. These fertilizers supply potassium which is one of the essential macronutrient of the plants. Examples of potassic fertilizers are:

(i) Muriate of potash or potassium chloride, KCl;

(ii) Potassium sulphate, K2SO4;

(iii) Potassium nitrate KNO3.

4. Complex fertilizers.

When a fertilizer contains at least two or more nutrients (N, P2O5) and K2O), it is called complex fertilizer. Examples of complex fertilizers are: (i) Nitrophosphate; (ii) Ammonium phosphate, (iii) Use ammonium phosphate.

Fertilizers should be applied scientifically, in terms of proper dose, time pre-and post application precautions for their complete utilization. For example, sometimes due to excessive water, fertilizer gets washed away and do not get fully absorbed by the plants. Fertilizers generally get washed off through irrigation, rainfall as drainage, and pollute rivers, lakes, streams (causing toxicity, algal bloom and eutrophication) and disturbing the ecosystem. The water of these water bodies becomes unfit for human consumption and even kills the aquatic such as fishes. So, chemical fertilizers must be used carefully and judiciously.

DIFFERENCES BETWEEN MANURE AND FERTILIZER

Manure Fertilizer
Manure is a natural substance. It is obtained by the decomposition of animal wastes such as dung (gobar) of cattle and buffaloes and plant residues. A fertilizer is a human-made a substance. It is an inorganic salt or an organic compound.
Manure contains small amounts of essential plant nutrients such as nitrogen, phosphorus and potassium. Fertilizers are very rich in plant nutrients such as nitrogen, phosphorus and potassium.
Manure adds a great amount of organic matter in the form of humus in the soil. A fertilizer does not add any humus to the soil.
Nutrients present in the manure are absorbed slowly by the crop plants, since manure is not soluble in water. Nutrients exist locked inside the organic compounds of humus. Being soluble in water, a fertilizer is readily absorbed by the crop plants.
Manure is not nutrient specific and it tends to remove the general deficiency from the soil. A fertilizer is nutrient specific. It can specifically provide nutrients such as nitrogen, phosphorus and potassium to the soil according to the need.
Manure is voluminous and bulky so it is inconvenient to store, transport, handle and apply to the crop. A fertilizer is compact and concentrated so it is easy to store, transport and apply to the crop.
Manure is cheap and is prepared in rural homes or fields. A fertilizer is costly and is prepared in factories.

5.Biofertilizers. Organisms which enrich the soil with nutrients are called biofertilizers. Biofertilizers are used for the specific crop plants such as pulses, legumes, oil seeds and rice. Biofertilizers are renewable and non-pollutant sources of plant nutrients such as nitrogen. They are not alternatives to chemical fertilizers but can play a supplementary role is supplying nitrogen to specific crop under specific soil conditions Nitrogen-fixing microorganisms, i.e., non-symbiotic and symbiotic cyanobacteria and phosphate- solubilizing microorganism are the main type of biofertilizers that are being in India. Recently, two biofertilizers, namely Rhizobium cultures and blue green algae (such as Anabaena and Nostoc) have gained popularity amongst farmers cultivating pulses, legumes, oil seeds and wet land rice.

6.Mycorrhiza. Mycorrhiza is a symbiotic (mutualistic) association of certain fungi with roots of higher plants). Mycorrhiza increases water and nutrient uptake by plants and increase growth, vigour and yield of the plants.

Advantages of fertilizers

They are mostly inorganic compounds, which can readily dissolve in water. They are easily available for plants. They are a good source of nitrogen, phosphorus, and potassium. However, they are good only for a short term use.

Disadvantages of fertilizers

They get washed away because of irrigation. Hence, they are a cause of water pollution. Continuous use of fertilizers causes harm to useful or symbiotic microorganisms living in soil. They can also result in the reduction of soil fertility. They cannot replenish the organic matter of soil. Therefore, to get an optimum yield, it is necessary to use a balanced combination of manures and fertilizers.

ORGANIC FARMING

This method of farming involves a limited use of chemicals such as fertilizers, pesticides, herbicides, genetically-modified organisms, etc. Sometimes they are not used at all. This system of farming is called organic farming. This method utilizes farm-wastes such as excreta, healthy cropping system (mixed cropping, intercropping, and crop rotation), the use of bio-pesticides (such as neem and turmeric leaves mixed with stored gains etc.). This method is effective for providing nutrition in plants, managing pests, and producing a good yield.

3.6 IRRIGATION SYSTEM

Rainfall in India is seasonal, but farming is practised throughout the year. During summers and winters, how do farmers supply water to their agricultural lands? Farmers supply water to their agricultural lands by using ground water or from a nearby reservoir. The method of providing water is known as irrigation. Irrigation is the process in which water requirement, usually for agricultural activities, is met from sources other than rain water. Earlier, rain water was the only source for meeting the water requirements of the growing crops. But, scarcity of rain resulted in low crop yielding. Thus, more methods were developed in order to improve water availability for crop production. This helped in better irrigation management, which led to a higher yield of crops.

TYPES OF IRRIGATION SYSTEMS

Dug wells and tube wells are used to supply water in crop fields. Tube wells are used to pump up the ground water and to release it in fields as per the requirement. Canals are man-made water channel systems, which are used to deliver adequate water to the fields. Canals are connected with water reservoirs, or rivers to distribute water in the fields. In a river lift system, river water is directly drawn from the river and is supplied to irrigate fields closer to the river. This is because in some regions, canals are irregular and insufficient because of low water levels in the river. Tanks are small, water storage reservoirs. These are helpful in delivering water in smaller areas.

ADVANTAGES OF IRRIGATION

In agriculture irrigation fulfill the following goals: Crop plants are irrigated with freshwater to supply two essential elements to them, hydrogen and oxygen.

Both of these elements are present in water molecules and are necessary for growth and development of crop plants.

Irrigation of crop fields is necessary to provide sufficient moisture for the germination of seeds, as seeds do no germinate in dry soils. Irrigation of crop plants is essential for the growth and elongation of the roots of the crop plants. This is because roots of crop plants fail to develop and elongate in dry soil.

Irrigation is necessary to increase the number of aerial branches (called tillers) in crop plants so as to get a good crop yield. Irrigation is essential for the absorption of nutrient elements by the crop plants from the soil.

The irrigation water tends to dissolve the nutrients present in the soil of a crop field to form a solution. The solution of nutrients is then absorbed by the roots of crops for the development of the plants.

SOME OTHER ADVANTAGES OF IRRIGATION

Irrigation has many other advantages compared to natural rain water supplies.

The supply of water by irrigation is regular and reliable, where as rainfall is often seasonal or unpredictable. Irrigation water supplied by rivers in flood often carries silt which adds to soil of the fields, enhancing fertility and crop yield. With irrigation, cultivation can be done round the year and not during the rainy season only. In desert area, the constant flow of irrigation water through the soil helps to reduce the salinity of the soil. However, if the water is allowed to evaporate in the fields, salt content of soil will increase. Modern multipurpose dams not only provide water for irrigation but also help to control floods, generate hydroelectric power and improve the navigability of the rivers.

FACTORS CONTROLLING IRRIGATION

The irrigation of water requirements of crop plants depends on the following two factors: Irrigation dependent on the nature of the crop plants (i.e., crop-based irrigation) Irrigation dependent on the nature of soil of the crop fields (i.e., soil-based irrigation).

Crop based irrigation. Water requirements of different crops are different during the various stages of their growth and maturation (ripening). Some crop plants require more water, while others need less water. For example, paddy crop (rice crop) is transplanted in standing water (wet lands) and requires continuous water supply, whereas, other crops such as wheat, gram and cotton requires less water. For cereals such as wheat, irrigation is required before ploughing the field (i.e., before tilling), at the time of flowering and at the time of development of the grain.

Soil based irrigation. Irrigation also depends on the nature of the soil in which crop is grown. The crops grown in a sandy soil need irrigation more frequently, whereas the frequency of irrigation is comparatively less for crops grown in a clayey soil. Let us find out why this occurs! Sandy soil is highly porous, and has high permeability. When the crop plants standing in a sandy soil are irrigated, water quickly percolates down the soil and the crop plants are not able to absorb adequate amounts of water. So, due to the poor water retaining capacity of the sandy soil, the crops cultivated in sandy soil need more frequent irrigation, In contrast to sandy soil, clayey soil is much less permeable, so it can retain water for a much longer time. So, when the crops grown in a clayey soil are irrigated, the water persists in the soil for a longer time and as a consequence plants grown in clayey soil can absorb this water in adequate amount. Thus, due to good water retaining capacity of the clayey soil, the crops cultivated in clayey soil need irrigation less frequently.

SOURCES OF WATER FOR IRRIGATION

River is the most commonly used water resource in the irrigation system.

Ground water is also used as a source of water in the irrigation system.

Rain water and flood water are often harvested to be used in irrigation.

Waste water from cities is treated and used as a source of water in agricultural lands.

3.7 CROPPING TECHNIQUES

Have you noticed different crops growing together in the same field? Do you know the reason for this? Farmers often grow different crops together without any definite pattern. You will also see that different crops are grown in a definite pattern i.e. in a sequence (like alternating each crop with the other etc.). These methods increase the yield.

How does growing of different crops in a definite pattern in a field increase the yield? Three different cropping patterns, namely mixed cropping, intercropping, and crop rotation are generally practised.

MIXED CROPPING

Mixed cropping allows two or more crops to be sowed simultaneously in the same land. Wheat and gram, wheat and mustard, ground nut and sunflower etc. are some common examples of mixed cropping. In mixed cropping, crops are chosen in such a way that they require different amounts of minerals.

ADVANTAGES OF MIXED CROPPING

The risk of total crop failure due to uncertain monsoon in reduced. Farmers tend to harvest a variety of produce such as cereal, pulses or vegetables or fodder to meet the various requirements of family or of an agricultural farm.

Due to complementary effect of component crops, yield of both crops is increased, e.g., wheat and gram.

Fertility of the soil is improved by growing two crops simultaneously. Changes of pest infestation are greatly reduced.

INTERCROPPING

Intercropping allows farmers to grow two or more crops simultaneously in the same field in a definite pattern. For example, cauliflower and chilli plants are grown together in alternating rows. To ensure the maximum utilization of nutrients applied, crops are selected in such a way that their nutrient requirements are different. Other examples include soya bean and maize, finger miller (bajra) and cowpea (lobia) etc.

ADVANTAGES OF INTERCROPPING

It makes better use of the natural resources of sunlight, land and water. Soil erosion is effectively arrested. Since the seeds of the two crops are not mixed before sowing, fertilizers can be added as per the need of the crops.

Since the seed maturity period of these crops varies, the different crops can be harvested and threshed separately. The produce of each crop can be marketed and consumed separately.

COMPARISON BETWEEN MIXED CROPPING AND INTERCROPPING

Mixed cropping Intercropping
It aims to minimize risk of crop failure It aims to increase productivity per unit area.
Seeds of two crops are mixed before sowing Seeds of two crops are not mixed
It involves no set pattern of rows of crops. It involves set patterns of rows of crops.
In this method there is a difficulty of fertilizer application to individual crops. In intercropping fertilizer can be placed as per need of the crops.
Spraying for pest control to individual crop is difficult. Pesticides can be easily applied to individual crop.
Harvesting and threshing of crop separately not possible. Both crops can be easily harvested and threshed separately.
Marketing and consumption of only mixed produce is possible. Product of each crop can be marketed and consumed separately.

CROP ROTATION

Crop rotation is the practice of growing two or more varieties of crops in the same region in sequential seasons. A common example of crop rotation is to cultivate maize followed by soya bean. This system also helps in preventing crops from pests and diseases. The crops selected, vary in nutrient requirements. This ensures complete and uniform utilization of nutrients. Mixed cropping also increases soil fertility by maintaining microbial diversity.

TYPES OF CROP PROTECTION

Type of crop rotation Component crops involved in rotation
One year rotation Maize – Mustard Rice – Wheat
Two years of rotation Maize – Mustard – Sugarcane – Fenugreek Maize – Potato – Sugarcane – Peas
Three years of rotation Rice – Wheat – Moong – Mustard – Sugarcane – Berseem Cotton – Oat – Sugarcane – Peas – Maize – Wheat

3.8 CROP PROTECTION MANAGEMENT

Crops are affected by pests and a large number of weeds in fields. Uncontrolled growth of weeds and pests reduce productivity. Also, after harvesting, the produce is still at danger of getting spoilt by various biotic and abiotic factors. Therefore, these factors must be controlled to prevent loss.

Let us first learn about the factors that affect crop plants and measures used to control them.

WEEDS

Weeds are plants that grow in cultivated fields along with the crop plant. They compete with the crop plant for nutrients, light, and space. As a result, the crop plant gets lesser nutrient, light, and space. This reduces the productivity of crop plants. Xanthium (gokhroo), Parthenium (gajar ghas), Cyperinus rotundus(motha) are some examples of weeds.

PESTS

These are generally insects. They destroy crops by the following methods:

Sucking the cellular sap from various plant parts Cutting the roots, stem, and leaves of plants Boring into stems and fruits

MICRO-ORGANISMS OR PATHOGENS

These cause diseases in crop plants. Pathogens can be bacteria, fungi, or virus. These pathogens are generally transmitted through soil, water, and air.

Protect crops from pests, weeds, and infectious agents Using pesticides is the most common method used to eradicate weeds, pests, and infectious diseases. Herbicides are used to eradicate weeds. Fungicides are used to destroy fungus. Insecticides are used against insects. These chemicals are generally sprayed on crops. Weeds can also be eradicated by the following methods:

mechanical removal

proper soil and seed preparation

timely sowing of crops, intercropping ,and crop rotation

use of resistance variety of crops, which resist the attack of pathogens

summer ploughing, which includes deep ploughing to destroy weeds and pests Chemicals should be used in limited amounts. An excessive use of chemicals can lead to several environmental problems. Moreover, these chemicals are poisonous for plants and animals.

Do you know that Bacillus thuringiensis is an insect pathogen, used as a bio-pesticide. It kills a wide range of insect larvae.

After harvesting, the grains are stored in store houses. There are certain factors that affect the produce after harvesting.

FACTORS AFFECTION THE PRODUCTION

Different biotic and abiotic factors can affect the storage of grains. The biotic factors are insects, rodents, fungi, mutes, bacteria. The abiotic factors are moisture, temperature. These factors result in:

(i) Weight loss

(ii) Poor seed quality

(iii) Poor germination rate

(iv) Discolouration of grains

These factors bring down the cost and profits. Therefore, proper management of stored grains is important. The methods listed below help in the proper maintenance of stored grains. Cleaning of floors before storing the grains.

Frequent chemical fumigation (to kill pests, fungi etc.).

Proper aeration and ventilation to control moisture and temperature levels.

3.9 ANIMAL HUSBANDRY

Animal husbandry is the science of managing animal livestock. It involves feeding, breeding, and controlling diseases in farm animals. Animal husbandry involves the rearing of animals like cattle, poultry, and fish to obtain desired products from them.

CATTLE FARMING

You can visit a dairy in order to have a better idea of cattle farming. Many products like curd, cheese, butter etc. are produced in a dairy. Can you think of some more milk products? A dairy farm rears cows and buffaloes, which provide milk, the primary material for all these products.

METHODS OF FARMING CATTLE

In India, two different species of cattle are widely reared, Bos indicus (cow) and Bos bubalis (buffalo). The purpose of cattle farming is usually for the production of milk and labour in agricultural fields. Female dairy animals used to obtain milk are known as milch animals. The production of milk depends upon the lactation period. Male animals are engaged in agricultural fields for labour work like carting, irrigation, tilling etc.

Cattle used for labour is called draught animal. Cattle management involves maintaining proper shelter facilities and regular cleaning. Animals require a regular bath and brushing to control the spread of diseases. They should be kept under a well-ventilated roof, which will prevent them from the heat, cold, and rain.

BREEDING CATTLE

Choosing improved breed is another element of cattle management. Hybrid cattle breeds are produced for improved productivity. For example, two breeds with required qualities are cross-bred.

Exotic or foreign breeds like Jersey, Brown Swiss etc. are selected for increased milk production. Local breeds like Red Sindhi, Sahiwal etc. are highly resistant to diseases. These two breeds are crossed to produce a hybrid breed, in which both the characteristics are available. Therefore, the offspring not only produces more milk, but is also more resistant to diseases.

FEEDING CATTLE

The cattle should be provided with healthy and nutritious food. Their food requirements can be classified into two types based on:

General/maintenance requirement: It provides nutrition to support a healthy life.

Milk producing requirement: It provides nutrition for lactation. Cattle should be provided with a well balanced diet which contains:

Roughage which largely consists of fibre

Concentrates, which have high levels of protein and other nutrients but also contains low-fibre

Additives which promote their health and milk production

DISEASES AFFECTING CATTLE

A variety of diseases affect cattle. Parasites are the common cause for these diseases. Parasites present on the body surface (called external parasites) of an animal cause skin diseases. The internal parasites include worms (in the stomach and intestine) and flukes (in the liver). Cattle are also affected by viral and bacterial diseases. However, vaccination can be given to prevent viral and bacterial diseases.

POULTRY FARMING

Poultry farming involves large-scale rearing of poultry birds. Why is poultry farming required? Poultry farming is undertaken to meet an increased demand of eggs and chickenIt deals with the management of domestic fowl in order to improve the quality and productivity of egg and chicken.

Improvement in poultry variety is achieved through the process of hybridization or cross breeding. Hybridization between an Indian breed like Aseel and a foreign breed like Leghorn has been done to bring about desirable traits in the improved variety.

SOME BENEFICIAL VARIETIES ARE

(i) Quality and size of eggs

(ii) Low maintenance breeds

(iii) High resistance to diseases

(iv) Tolerance to high temperature

(v) Quality and quantity of chicks

(vi)  Ability to utilize cheaper diets produced from agricultural wastes (viii) Dwarf boilers for egg production( so that they consume lesser nutrition for body growth)

Poultry birds are bred for eggs and meat

Boilers are reared for meat. They are fed with protein and vitamin-rich supplements (mainly vitamin A and vitamin K), with adequate amounts of fat. This helps in maintaining their feather and carcass quality. It also reduces mortality rate. Nutritional requirements are different for egg and meat production. Food supplemented with respective nutritional needs is provided. Housing of the two types also varies.

For good production of poultry, proper management techniques should be followed. Regular cleaning of the farm is of utmost importance. Maintenance of temperature is also required.

DISEASES OF POULTRY

Poultry birds suffer from a variety of diseases which are caused by bacteria, virus, fungi, or parasites. They also suffer from nutritional deficiencies. These diseases in the poultry birds can result in economic losses.

Preventive measures include providing a clean housing area, with regular sanitation, and spraying of disinfectants. Vaccination also prevents the spread of infectious diseases.

You now know about poultry farms and dairy farms. However, have you ever heard about a fish farm? What do you think is done in fish farms? Let us explore.

FISH FARMING

Fish farming is the practice of raising fish population commercially. It involves the production of aquatic animals, which are of high economic value like prawns, fishes, lobsters, crabs, shrimps, mussels, oysters etc. There are two ways of obtaining fishes:

Capture fishing is the process of obtaining fishes from natural resources Culture fishery is the practice of farming fishes Farming can be done in both fresh water (such as rivers, ponds etc.) and marine ecosystems.

Marine fisheries

In India, marine fishery is carried out along the 7,500 km coastline and the deep seas beyond it. Fishing is done using fishing nets and boats. The amount of fishes caught can be increased by locating schools of fishes using satellites or echo sounders. Some examples of marine fishes include mackerel, tuna, sardine, pomfret, and bombay duck. Some varieties of marine fish are of high economic value and include finned fishes (like pearl spot, bhetki, mullet etc.) and shelled fishes (like prawns, mussels, oysters etc.). The cultivation of marine organisms for a commercial purpose is known as mariculture.

Inland fisheries

Canals, ponds, and rivers are some freshwater resources. Brackish water resources are generally found where seawater and fresh water occur together. It includes estuaries and lagoons. Fresh water fisheries and brackish water fisheries are called inland fisheries.

An intensive way of farming fishes is the composite fish culture system. In such a system, five or six different species of fishes are grown together in a single fishpond.

Fishes with different food habitats are chosen, so that they do not compete for food among themselves. For example, catla feed on the surface of water, rohu are middle zone feeders, mrigal and common carp are bottom feeders, and grass carp feed on weeds.

This ensures complete utilization of food resources in the pond. Such a system increases the fish yield.

A major problem with this system is that many of these fishes breed only during monsoon. However, the use of hormonal stimulations has provided a solution for this problem.

Do you know why fishes obtained from fisheries are more useful commercially?

The fishes obtained from fisheries are larger as they receive proper food, and have a healthy environment for their growth. Thus, they are commercially useful.

SOME INTERESTING FACTS

Do you know that a person who studies fishes is called an ichthyologist? The largest fish is the whale shark. It can grow to more than 15 m in length. The smallest fish is the freshwater goby, and it is less than 1 cm in length. It is found in the Philippine islands.

APICULTURE

We know that the honey we use is produced by bees, but how is this honey obtained commercially? Are there any bee farms like cattle and poultry farms? Let us find out.

Bee keeping

Bee keeping is practiced all over the world. Its products are honey, bees wax etc.

Honey has many uses. It has medicinal value and is useful in the treatment of many disorders like cold, cough, flu, dysentery etc. Therefore, bee keeping has become a popular agricultural enterprise for the production of honey.

Apiculture

The practice of bee keeping is known as apiculture, and the bee farms are known as apiaries.

Bee keeping industry has become an additional income generating activity among farmers as it requires low investment. Moreover, beehives can also be used as a source of wax. Bees wax is used in several medicinal preparations.

Varieties of Bees

In India, both local and foreign breeds are used for commercial honey production. Local breeds include Apis cerana indica (Indian bee), Apis dorsata (rock bee), and Apis florae (little bee).

Commercially, the Italian breed Apis  mellifera is used for honey production. This is because of the following reasons:

They yield large quantities of honey

Since they do not sting much, the collection of honey becomes easier They stay in their beehives for long durations They breed very well

Quality of honey produced

The quality of honey produced does not depend upon the variety of bees used. The quality of honey is greatly affected by both the quantity and quality of the available flowers, from which bees collect nectar and pollen.

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