Improvement in food Resources (Plants) for biology class 9

Food is essential for all living organisms to live. We depend on plants and animals for food. The increase in population has created much demand for food. It is important that we should increase food production without degrading our environment and disturbing the balances maintaining it.

All the living organisms, only green plants are autotrophs, i.e., they make their own food.

Green plants perform a basic metabolic activity called photosynthesis. In photosyntheses by using the energy of sunlight, green plants combine carbon dioxide (CO₂) and water (H₂O) to produce carbohydrates (Food).
 In Contrast to green plants, animals and human beings are heterotrophs. They depends on plants and other animals for food.

The crops which are grown in rainy season (the kharif season, from June to October) are called as kharif crops.

Example: Paddy, soyabean, pigeon pea, maize, cotton, green gram and black gram are kharif crops.

The crops which are grown in winter season (the rabi season, from November to April) are called rabi crops.
Example: Wheat grain, peas, mustard and linseed are rabi crops.

Green Revolution
Green Revolution is a programme introduced in many poor countries to increase food production by use of modern technology, proper irrigation, improved seeds, etc.

White Revolution

White Revolution is a programme introduced in India to increase production of milk in India. This programme made India self – sufficient m production of milk. 

Similarly Blue Revolution was introduced to enhance fish production. 

Yellow Revolution was introduced to increase oil production.

 Golden revolution was introduced to increase Pulse production. 

Silver Revolution was introduced to increase egg production.

 Pink Revolution was introduced to increase meat & poultry processing sector. 

Sustainable Agriculture

Sustainable agriculture may be defined as the practice of farming and production of maximum agricultural yield through management of natural resources without disturbing the environment.

• Conserving natural resources
• Maintaining environmental balance
• Coping with changing human needs

 It is necessary to adopt sustainable agriculture practices such as mixed farming, crop rotation, intercropping and integrated farming (also known as integrated agriculture).

 Various Problems associated with environment degradation:

Soil erosion, salinization of soils, desertification, silting of rivers, floods, droughts, eutrophication, ozone depletion, deforestation, wild life extinction, pollution of air, water and land, biomagnifications of toxic substances,. Etc

 Eutrophication: excessive richness of nutrients in a lake or other body of water, frequently due to run off from land, which causes dense growth of plant life.

Biomagnification: is the process of accumulation of certain chemicals inliving organisms to a concentration higher than that occurring in the inorganic , non – living components.

 Advantages of sustainable agriculture:

• Achieves the integration of natural biological cycles and controls.
• Protects and renews soil fertility and the natural resources base.
• Optimizes the management and use of farm resources.
• Reduces the use of non-renewable resources and purchased production inputs.
• Provides an adequate and dependable form of income.
• Promotes opportunity in family farming and farm communities.

 Method of Sustainable Agriculture:

Farming: It is the process the harnessing solar energy form plants and animals in the form of economic produce.

 Conservation: It means careful utilization, preservation or restoration of the natural environment and resources.

 Integrated agriculture:

1. a) Pisciculture (fish culture) b) aquaculture
2. c) apiculture (bee-keeping) d) sericulture (silk worm culture)
3. e) poultry farming . f) piggery
4. g) livestock production (animal husbandry)

Agriculture and Organic Farming

Once, India was a self-sustainable country and at its backbone was agriculture. Agriculture can be defined as the art of growing food crops and cash crops needed by man. This has passed through a series of phases. Agricultural practices and technologies have grown rapidly and selection of farming method totally depends on the financial condition of the farmer. The ultimate aim of all these farming practices is to achieve better and higher yield. Agriculture can be either sustainable agriculture, industrial agriculture or organic agriculture. In this section, we will discuss organic farming. 

What Is Organic Farming?

It is the practice of farming or raising of crops and other livestock without using any inorganic chemical fertilizers, pesticides, biofertilizers and biopesticides or any other genetically modified organisms. With organic farming, the productivity of the farming fields is enhanced along with economic growth, thus promising a sustainable environment. Nowadays, farmers are aware of the harmful and toxic effect of fertilizers and other chemicals used. As a result, they started to rely on organic farming. It has many benefits over other practices. They are eco-friendly and help to reduce the soil infertility and soil erosion issues. It enhances lifestyle.

 Types of Organic Farming:-

Organic farming is primarily of two types, namely:

1. Pure organic farming
2. Integrated organic farming

Pure organic farming involves avoiding all artificial chemicals. Every fertilizer and pesticide that are used are derived from completely natural sources such as blood meal or bone meal.

Integrated organic farming involves integrating techniques aimed at achieving ecological requirements and economic demands such as integrated pest management and nutrients management.

 Improvements in Yields:-

There are 3 scientific approaches adopted in India to obtain high yields from our agriculture farms :-

• Crop Production Management
• Crop variety improvement
• Crop protection Management

 Crop production management is the process that is used to effectively cultivate and harvest crops in order to obtain the maximum and best yield . It has the following three components :-

• Nutrient management
• Irrigation
• Cropping Pattern

Nutrient management

Food is essential for our growth, development and well-being. Just like all living organisms, plants also require nutrients. These nutrients are provided by water, air, sunlight and soil.

There are sixteen nutrients which are essential for plants. Air supplies carbon and oxygen, hydrogen comes from water, and soil supplies the other thirteen nutrients to plants.

 What is Nutrient Management?

Nutrient management refers to the efficient use of crops to improve productivity. It is necessary to balance the soil nutrient input with the crop requirement. If the nutrients are applied at the right time and in adequate quantities, optimum crop yield is obtained.

If applied in huge amounts, it will harm the crop, and if applied in small quantities it limits the yield.

The nutrients that are not utilized by the crops leach into groundwater or nearby surface water.

Integrated Nutrient Management

Integrated nutrient management is the combined application of   chemical fertilizers and organic manures for crop production.

Its main aim is the maintenance of soil fertility and the supply of plant nutrients in adequate amounts. It is ecologically, socially and economically viable.

Concepts of Integrated Nutrient Management

• The nutrients stored in the soil.
• The nutrients purchased from outside the farm.
• Plant nutrients present in crop residues, manures, and domestic wastes.
• Nutrient uptake by crops at harvest time.
• Plant nutrients lost from the field during crop harvest or through volatilization.

Macronutrients

Among the 13 essential nutrients obtained from Soil , 6 are the most essential nutrients required in abundance for the growth and development of plants. These essential nutrients are collectively called macronutrients.

Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Sulfur (S), and Magnesium (Mg) are the macronutrients required by plants.

Micronutrients

Among the 13 essential nutrients, 6 are classified into macronutrients and the other 7 are classified into micronutrients. These nutrients include: iron (Fe), boron (B), chlorine (Cl), manganese (Mn), zinc (Zn), copper (Cu) and molybdenum (Mo).  They are required in very small quantities, therefore, they are also called trace minerals.

Role of Manures and Fertilizers in Nutrient Management

Manures

• Contains small quantities of nutrients and large quantities of organic matter
• Formed as a result of decomposition of plant wastes and animal excreta
• Enriches soil with nutrients and organic matter thereby increasing its fertility
• Bulk organic matter improves soil structure, which increases water-retaining capacity in sandy soil, helps in drainage and water clogging in clayey soil.
• Manure contains biological wastes obtained as a result of recycling and is preferred over the use of fertilizers.

Advantages of Manure

• These are a good source of macronutrients.
• Improves soil fertility.
• Cost-effective
• Reduces soil erosion and leaching.
• Improves the physical properties of the soil and aerates the soil.
• Improves the water and nutrient holding capacity of the soil.
• Methane gas is evolved as the by-product of manure that can be used for cooking and heating purposes.
• The crops grown on the land treated with manure produces healthy crops. 

Manure can be classified into two types based on the kind of biological material used: Compost and Vermicompost

Composting is carried out using farm wastes. Vermicompost is prepared using earthworms.

Green manure: Some green plants are mulched into the soil while sowing seeds, which helps enrich the soil with nitrogen and phosphorous.

Types of Manure

Manure can be grouped as farmyard manure, green manure and compost manure. Following are the different types of manure used by the farmers:

Green Manure (used for crops requiring high Nutrient input) .

Green manure increases the percentage of organic matter in the soil. The roots of such manures go deep into the soil. These help in the suppression of weeds and the prevention of soil erosion. In this method, crops are grown in the field for about 6 to 8 weeks and are overturned when in tender stage. These crops remain buried for about one to two months. During this period, plants should be completely decomposed before sowing the next crop .

Farmyard Manure

Farmyard manure (FYM) is a decomposed mixture of dung, urine, litter, and leftover materials from roughages and fodder fed to animals. Farmyard manure improves the soil structure and is used as a natural fertilizer in farming. It increases the soil capacity to hold more water and nutrients. It also increases the microbial activity of the soil to improve its mineral supply and also the plant nutrients.

A well-decomposed FYM contains 0.5 – 1.5% N, 0.2 – 0.4% P₂O₅, and 0.5 – 1.0% K₂O. FYM is a good source of organic carbon, which activates the biotic life of the soil flora and fauna

Compost Manure

Compost, or synthetic manure, is basically a mass of rotted organic matter made from waste-plant residues – compost bin. Compost can be prepared on a small scale for home gardens, usually in a simple pile of yard waste and kitchen scraps, though compost bins and barrels are also used.

It improves the soil structure and water and nutrient holding capacity of the soil. Thus, it increases the nutrient value and thereby improves the health of the plants.

Vermicompost

Vermicompost is utilising the household waste to make compost or green manure for the plants. Vermicompost is the process of composting with the help of various worms, that creates a heterogenous mixture of decomposing vegetable or food waste, and that can be used as manures in vegetation fields and gardens.

Earthworms are used in the process as they can stabilize organic materials faster than microorganisms because speed up the process and surface area as they grind the organic materials much faster.
The material that results from the process is called vermicompost. Vermicompost contains a large amount of castings, which are, the material that passses through the gut of the worms.

Dried leaves are mainly used in the process of vermicomposting that are otherwise burned to get rid of. When burned, they add to unnecessary environmental pollution and lung related diseases. A much better option would be to use the dried leaves in vermicomposting the garbage.

Compost and Vermicompost Manure

What are Fertilizers?

Fertilizers are chemical substances supplied to the crops to increase their productivity. These are used by the farmers daily to increase the crop yield. The fertilizers contain the essential nutrients required by the plants, including nitrogen, potassium, and phosphorus. They enhance the water retention capacity of the soil and also increase its fertility.

Types of Fertilizers

There are six different types of fertilizers that are mentioned below:

Inorganic Fertilizers

Inorganic fertilizers are chemical fertilizers that contain nutrient elements for the growth of crops made by chemical means. The inorganic fertilizers are of the following types:

Nitrogen Fertilizers

Nitrogen fertilizers contain nitrogen necessary for the development of crops. Nitrogen is the main constituent of chlorophyll that maintains a balance in the process of photosynthesis. It is also a part of amino acids in plants and constitutes protein. Nitrogen fertilizers improve the production and quality of agricultural products.

Phosphorus Fertilizer

The main nutrient in a phosphorus fertilizer is phosphorus. The efficiency of fertilizer depends upon effective phosphorus content, methods of fertilizing, properties of soil and crop strains. Phosphorus found in the protoplasm of the cell plays an important role in cell growth and proliferation. The phosphorus fertilizer is beneficial for the growth of roots of the plants.

Organic Fertilizers

Organic fertilizers are natural fertilizers obtained from plants and animals. It enriches the soil with carbonic compounds essential for plant growth. Organic fertilizers increase the organic matter content of the soil, promotes the reproduction of microorganisms, and changes the physical and chemical properties of the soil. It is considered to be one of the main nutrients for green food.

Organic fertilizers can be obtained from the following products:

• Agricultural Waste
• Livestock Manure
• Industrial Waste
• Municipal Sludge

Advantages of Fertilizers

The advantages of fertilizers are mentioned below:

• They are easy to transport, store, and apply.
• For supplying a specific nutrientwe can select a specific fertilizer due to its nutrient specific nature.
• They are water-soluble and can easily dissolve in the soil. Hence, they are easily absorbed by the plants.
• They have a rapid effect on the crops.
• They increase the crop yield and provide enough food to feed the large population.
• They are predictable and reliable.

Disadvantages of Fertilizers

Fertilizers have the following disadvantages:

• They are expensive.
• The ingredients in the fertilizers are toxic to the skin and respiratory system.
• Excessive use of fertilizers damages the plants and reduces soil fertility.
• Leaching occurs and the fertilizers reach the rivers causing eutrophication.
• Long term use reduces the microbial activity and disturbs the pH of the soil.

Uses of Fertilizers

Fertilizers are used for various purposes. The uses of fertilizers are mentioned below:

• They are used to providing additional nutrients to the plants.
• They are added to improve the yield of the crops.
• Nitrogen-rich fertilizers are used for the greening of lawns.
• Organic fertilizers improve the texture and fertility of the soil.
• Gardeners use fertilizers to address certain needs of the plants such as nutritional needs.
• Fertilizers are added to potted plants to replace the lost nutrients. 

Bio-fertililzers :- Since the chemical fertilizers adversely affect soil fertility, biofertilizers were brought into use. These are substances that contain living or latent cells, and even micro-organisms. They provide the soil with the necessary nutrients and microbes for the growth of the plants. They help the soil to retain its fertility. They are environment-friendly and also destroy pathogenic components responsible for causing disease in plants. Blue green algae (such as Anabaena and Nostoc) and Rhizobium are two such widely used biofertilizers. 

Irrigation

It is a process of application of water in controlled amounts at regular intervals to the crops. Irrigation methods are adopted at various places especially in areas of low rainfall to ensure the proper growth of crops. 

Why do droughts occur?

The scarcity of water or low rainfall often results in drought conditions. If farmers do not use any irrigation methods and only rely on rainfalls, draught poses a serious threat to the crops. Areas with light soils also tend to face drought-like conditions as soils cannot retain water

Irrigation Methods                      

Wells: two types of wells are used for irrigation:

• Tubewell: tube wells are tube-like structures that are used to extract the underground water.

Dug Wells: dug wells are the wells dug in the ground in order to extract the underground water. Water from dug well and tubewell both is lifted by using pumps.

Canals: A canal system is a network created to move water from one source of water such as a stream or reservoir. The main canal is divided into branches that spread by through the fields so that water can be distributed everywhere.

River Lift System: A river lift system is used to draw water from the rivers directly for irrigational purposes. This system is successful in areas where the canal system is not successful.  

Tanks: farmers often use small storage reservoir that can store as well as supply water in the small fields. 

Rainwater Harvesting: Instead of just letting the rainwater flow away farmers often store it in the reservoir tank. This water can we for the used for irrigational purposes. 

Watershed Management: Small dams are built on the rivers and streams in order to increase the ground levels of the area. These check dams prevent water from flowing away and causing soil erosion.

Cropping Patterns

Different cropping patterns are used by farmers in order to increase the crop yield:

• Mixed Cropping
• Intercropping
• Crop Rotation

Mixed Cropping

• It is a cropping pattern in which two or more crops are grown together in the same field.
• The main aim of this cropping method is to ensure some healed even if one of the crops fails to grow properly.
• The seeds of different crops are combined and planted together.
• Same fertilizers are used for all the crops.

For Example, wheat and gram, wheat and mustard, groundnut and sunflower.

Intercropping

• It is a cropping method in which two or more crops are grown together in a field but in a specific pattern.
• The seeds of these crops are not combined before plantation.
• Both the crops used different kinds of fertilizers depending upon their own requirements.
• The main objective of this method is to ensure the maximum productivity of the crops.
• Since the crops have different nutrient requirements they would use maximum nutrients from the soil.
• Diseases and pest would also not easily spread to all the crops.
• For Example, soybean and maize, finger millets and cowpea.

Crop Rotation

• In this cropping method, different types of crops are chosen and irrigated on the same piece of land sequentially.
• The rotation of crops depends upon the soil, climate and water retention of the soil. How is crop rotation useful?
• If farmers grow the same crop on the land for long-term the same nutrients keep on depleting from the soil which leads to a decrease in the soil fertility.
• But when crops with different nutritional requirements are grown the soil nutrients get enriched and the fertility of the land is maintained.
• Different crops are not susceptible to all kinds of pests and diseases.
• Planting different crops on rotation can lead to a better yield.
• Crop rotation allows a reduction in the number of fertilizers and pesticides on the fields. 

• rop Protection  Management

  Factors that can affect the production of crops are weeds, pests and diseases.

  • Weeds: Along with crops, sometimes some other plants also grow up which are not needed. These are called weeds. Weeds can affect the crop as they utilise the nutrients from the soil that are meant to be used by the crops.

   Weed Control Methods:

  • Weedicides are sprayed on the fields that can kill them as they do not harm any crops.
  • Weeds can be uprooted manually by the farmers.
  • The crop is sown timely are not affected by weeds.
  • Using different methods of cropping suggest crop rotation and intercropping also reduce the chances of growing weeds.

Pests: Several insects and pests can affect the crops in different ways:

• They can cut the parts of the crops like fruits, leaves and stems.
• They can get into the stems and roots of the plants.
• They suck the cell sap of the plants and hence destroy them.

Pest Controlling Methods:

• • • Pesticides and insecticides are sprayed on the fields to kill the germs.
    • Crops should be checked timely to ensure safety against pests.
    • Usage of effective cropping methods such as crop rotation ensures insect management in the fields.
    • Sometimes summer ploughing is also used to destroy the weeds and pests.

Diseases: Microorganisms such as fungi, bacteria and viruses often attack the crops and affect them. These pathogens can be transmitted to the crops via soil, water or air.

 Disease Management Methods

• Selecting the crop that suits the temperature and climatic conditions of the place.
• Planting the seeds on right time and in an environment that favours their growth.
• Using herbicides such as dicamba and glufosinate ammonium and fertilizers such as ammonium nitrate, potassium sulfate.
• Using crop rotation method and mixed cropping.

 Storage of Grains

Factors that lead to storage losses of crops are:

• Biotic Factors:Like insects, fungi, bacteria, rodents and mites
• Abiotic Factors:Like excessive temperature and moisture.

 How to prevent storage loss?

• Maintaining the storage houses properly
• Cleaning the grains properly before storage
• Drying the grains properly before storage in sunlight as well as in the shade.