All living organisms need food because:

• It provides carbohydrates, fats vitamins and minerals
• It allows development of the organisms
• It is needed to gain energy for everyday tasks

Main sources of food:

• Plants – obtained from agriculture
• Animals – obtained from animal husbandry

The efficiency of crops and livestock is required in India because:

• The population of India is growing at a faster rate hence more amount of food is required to meet the rising demand.
• The agricultural land is limited as compared to the growing population.

Efforts made to meet the increase in food demands

• Green Revolution – The introduction of modern technology and equipment, usage of fertilizers and high-quality seeds
• White Revolution – Increasing the growth of milk production by introducing dairy development programs

The introduction of these revolutions has led to an increased use of natural resources hence now sustainable methods of increasing crops and livestock efficiency are also required.

To fulfil the need of food to geometrically growing population, the various practices involved in crop production should be more scientific. Till now following revolutions to increase food, fish, milk and oil production have been successful with due efforts made by scientist.

• Green revolution: for increase in food grain production.
• Father of green revolution –Father of green revolution in India – Mr. M.S.Swaminathan
• Blue revolution: for increase in fish production.
• White revolution: for increase in milk production.
• Yellow revolution: for increase in oil production.
• Golden revolution: for increase in pulse production

Different types of crop:
(A) on the basis of nutrients they provide:

• Cereals: contain high amount of carbohydrate to provide energy. e.g. – Wheat, Maize, Rice, Barley, Rye, Oats, Sorghum etc.
• Pulses: are rich in protein. e.g.- Gram (Chana), Black gram(Urad), Green gram)Moong), Pigeon gram(Arhar),Lantel(Massor)
• Oil yielding plant: provide fatty acid. e.g. – Ground nut, Castor, Cotton, Sunflower, Coconut, Mustered, Sesame, Linseed, Niger.
• Vegetable, Spices & Fruits: are sources of vitamins, minerals, and small quantity of protein, carbohydrate and oil. e.g. – Spices – Ginger, Turmeric, Cloves, Pepper, Fennel, Coriender, Cumin.
• Fibre yielding plant: e.g.- Cotton, Jute.
• Beverages: have very little nutritive value but are very stimulating. e.g.- Tea, Coffee
• Fodder crop: e.g. – Barsem, Sudan grass, Oat grasses

Different types of crops and their Nutritional Value

(B) On the basis of season in which they are grown:

• Kharif crop: grown in rainy season (from June to October) e.g. – Paddy, Soya bean, Arhar, Maize, Cotton, Urad, Moong etc.
• Rabi crop: grown in summer season (November to April) e.g.- Wheat, Gram, Peas, Mustard, Linseed “They are also called “summer season crop”.
• Since from 1960 – 2004 the total crop production has been increased by four times whereas only 25% increase in cultivated land has been seen. This can be made possible due to
  1. Choice of good & healthy seed.
  2. Supplying proper nutrition for crops.
  3. Protecting growing and harvested crop.

Crop	Season	Example
Kharif	Rainy (June to October)	Rice, maize, millets
Rabi	Winter (November to April)	Soybean, pigeon pea, wheat
Zaid	Summer (March to June)	Sugarcane, Watermelon, Cucumber

To obtain higher yield from farmland following three systems are being used:

1. Crop variety improvement.
2. Crop production management.
3. Crop protection management.

1. CROP VARIETY IMPROVEMENT:
The first and foremost important step to improve the crop yield is to improve the variety of crop which has following characteristics i.e. crop variety improvement is done for the following purposes:

1. Higher yield.
2. Better quality.
3. Biotic & abiotic resistance i.e. disease, insects & pest resistance.
4. Desirable agronomic characters for specific crops like dwarfness, intensive branching, more tillering & increased fertiliser responsiveness.
5. Wider adaptability: developed improved crops help in stabilizing crop production under
   different climatic conditions.
6. Early maturation(ripening)
7. Better response to fertilisers.

Crop variety can be improved by plant breeding. Plant breeding can be done either by selection or hybridisation.

Hybridisation is the crossing of two plants differing from each other genetically in one or more characters. By hybridisation it is possible to combine all the good characters in a single variety and to exploit & utilise the hybrid vigour. Hybridisation or crossing over may be Intervarietal (between different verities), Interspecific (between two different species of same genus) or Intergeneric (between different genera). The objective of hybridisation becomes more fulfilled by the genetic engineering. Nowadays the desired characters in plants can be obtained by introducing the gene of desired characters; such crops are called “Genetically modified crops” or GM Crops.

2. CROP PRODUCTION MANAGEMENT: Includes - Nutrients requirement, Irrigation & Cropping pattern.
(i) NUTRIENT REQUIREMENT: There are two types of nutrients required by the plants
(a) Macronutrients: needed by the plants in large amount. E.g.- N2, P, K, Ca,Mg, S
(b) Micronutrients: needed by the plants in very small amount.e.g. - Fe, Cu, Zn, Bo, Mo, Cl.

Sources of plant nutrients:

• Air – Carbon, Oxygen
• Water – Hydrogen
• Soil – N2, P, K, Ca, Mg, S, Fe, Mn, Bo, Zn, Co, Mo, Cl
  “Most important nutrients needed for growth of plants are N2, P, and K”.

Activities that lead to improvement in the crop yield:

• Crop Variety Improvement
• Crop Production Improvement
• Crop Production Management

Crop Variety Improvement

In this approach, crops are selected on the basis of their characteristics. For instance, how well they can respond to fertilizers, can they produce high yield, how they resist diseases and so on.

Different methods of Crop Variety Improvement

1. Hybridisation - In this process, genetically different plants are crossbred.

They can be three types of crossing

• Intervarietal - Between two varieties of a plant
• Interspecific - Between two species belonging to same genus
• Inter Generic - Between species of different genus

2. Introduction of Gene - A gene that can provide the desirable characteristics to a crop are introduced in this process. As a result, we obtain genetically modified crops.

Factors on which Crop Yield Generally Depends

• The seeds used by the farmers - The seeds that are of similar variety are preferable.
• Climate or Weather Conditions - Crops that can sustain diverse climatic conditions are preferable.
• The duality of the Soil - Crops that can survive in a highly saline soil are preferable.
• Availability of Water - Crops should be grown as per the availability of water in the region.

Why do we need to perform a crop variety improvement?

• Increasing the yield of the crops
• Improving the quality of the crop. Different crops may have different qualities. For Example, pulses have high protein quality, oilseeds have oil quality fruits and vegetables must have preserving quality.
• Improving crop resistance to biotic and abiotic stresses. Biotic stresses referred to the diseases, insects and nematodes while abiotic stresses referred to floods, drought, heat and cold weather conditions.
• To shorten the maturity period of crops. This will allow farmers to grow a variety of crops in a year.
• It would also lead to an increase in the yield of the crop as it reduces the chances of losses during the harvesting and simplifies the harvesting period.
• Achieving the required agronomic characteristics of crops such as the right height, weight, lodging, resistance and high yield. In this way, they would consume the right nutrients and would produce a higher yield.

Crop Production Management

Different farmers can have small or large farms on which they can use different farming practices. The choice of farming practices would depend upon the availability of financial resources money. Hence, production practices can be divided into different levels

1. No cost Production

2. Low-cost Production

3. High-cost Production

How can we increase the yield by providing all nutrients to the plants?

Using Manure - Manure is prepared by using animal excreta and plant waste.

Functions or Features of Manure

• Manure mainly contains organic matter which increases the fertility of the soil.
• It also contains nutrients in small quantity which are then supplied to the soil on adding manure.
• The soil structure also enhance is due to manure. It tends to hold more amount of water.
• The organic matter avoids waterlogging and drainage in clayey soil.
• Manure is purely organic hence using more manure is completely healthy for the plant as well as the environment.
• Using manure is a way to recycle farm waste.

What is composting?

The process of recycling farm waste material by decomposing it is called Composting. The product formed on decomposition is called Compost. The composed has a high variety of nutrients and organic matter. The material used in the preparation of compost is animal excreta, sewage waste, vegetable waste and weeds.

Differences between Manures & Fertilisers:

Manure	Fertilizers
Manure provides humus to the soil	Fertilizers do not provide humus to the soil
Manures are less rich in nutrients	Fertilizers are highly rich in nutrients
Long term usage of manure leads to increment in the fertility of the soil	Long term usage of fertilizers can lead to decrease in the soil fertility

Classification of Manure

1. Compost and Vermicompost Manure

2. Green Manure – sometimes specific plants are grown and then ploughed again in the soil. These plants decay and turn into manure which enriches the soil, mainly with nitrogen and phosphorus. Plants that are used in the production of green manure are hemp, clover, peas grass mixtures.

Using Fertilizers

Fertilizers are artificial materials that are produced on a commercial basis or natural substances that ensure nutrient benefits to the soil.

• Organic fertilizers used by Farmers: Limestone, rock phosphate
• Artificial fertilizers used by Farmers: Ammonium nitrate, potassium sulfate

Features of Fertilizers

• Fertilizers provide important nutrients such as nitrogen, potassium and phosphorus to the soil.
• They help in the proper growth of the plants.
• They are responsible for high yields in the high-cost farming methods.

Precautions with Fertilizers

• Fertilizers should be applied in a proper amount as an excess of fertilizers is not good for the plants.
• Proper precautions regarding the time of applying fertilizers should be taken.
• Excess use of fertilizers can lead to water pollution as the extra fertilizers get washed away during irrigation.
• Excess use of fertilizers can destroy the fertility of the soil as well.

How are fertilizers and manure different?

What is organic farming?

A farming practice which involves no use of artificial chemicals, fertilizers and pesticides and completely relies upon organic matter is known as organic farming. Organic farming uses healthy cropping systems such as crop rotation, intercropping and mixed cropping. Organic matter used in organic farming:

• manure
• bioagents such as blue-green algae
• biofertilizers
• Neem leaves and turmeric as biopesticides

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

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.