Biofertilizers | Biology for Grade 12 PDF Download

Biofertilizers :- These are the organism like bacteria, blue green algae and fungi (mycorrhiza) which enrich the soil in nutrients. Some important bio-fertilizers are :-

(1)  Bacteria as bio-fertilizers :- 

(a)  Symbiotic nitrogen fixing bacteria :Nitrogen Fixing Bacteria''Rhizobium leguminosarum'' : bacteria lives symbiotically in root nodules of legumes. In root nodules, Rhizobium fixes atmospheric nitrogen in the presence of red pigment ''leghaemoglobin''. 

Presence of phosphorus, is essential for nitrogen fixation.

One legume plant “Sesbania rostrata'' has double symbiotic relationship with nitrogen fixing bacteria → Rhizobium in the root nodules and ''Aerorhizobium caulinodans'' in stem nodules.

Frenkia, a nitrogen fixing filamentous bacterium associated symbiotically with the root nodules of non-legume plants like Casurina, Rubus, Alnus myrica.

(b)  Free-living nitrogen fixing bacteria :

Some bacteria like Azotobacter (aerobic) Clostridium (anaerobic), Beijerinckia (aerobic) are free living nitrogen fixing bacteria of soil, which increase fertility of soil.

Bacillus polymyxa is another example of free living nitrogen fixing bacterium.

(c)  Loose association of nitrogen fixing bacterium :

A bacterium ''Azospirillum lipoferum'' forms loose association with roots of maize and Brazilian grasses, which increases crop yield (Dobriner). 

(2)  Blue green algae (Cyanobacteria) as biofertilizers :

(a)  Free living nitrogen fixing BGA :

Blue green algae like Anabaena, Aulosira, Tolypothrix, Plectonema are the most common nitrogen fixing organism.

Blue green algae fixes Nitrogen with the help of ''heterocyst''. 

Photosynthesis provides the energy for nitrogen fixation.

''Aulosira fertilissima'' is the most active nitrogen fixer of rice field.

(b)  Symbiotic Nitrogen fixing cyanobacteria :

Azolla pinnata is a small aquatic fern inoculated to rice field of South-East Asian countries. It's leafy cavities contain symbiotic BGA-Anabaena, Nostoc, Oscillatoria. 

A. pinnata is best biofertilizer for rice. Farmers have reported 50%-higher yield of rice by using A.pinnata.  

(3)  Fungi as biofertilizer :- 

(i)   Mycorrhiza :- Symbiotic association between roots of higher plant and fungal hypae is called mycorrhiza. It is of two types:

(a)  Ectotrophic or ectomycorrhiza :- Fungal hypae are present on the surface of root, It increases water and nutrient absorption, growth & yield of plant.

e.g Found in Pinus, Oak, Eucalyptus. Hebeloma, Laccaria, Pisolithus are fungi which formed ectomycorrhiza.

(b)  Endotrophic or Endomycorrhiza :- Fungal hyphae are present inside or between the cells of cortex. It occurs in coffee, pepper, cardamom. Glomus, Gigaspora, Sclerocystis are fungi which formed endomycorrhiza.

In many grasses and orchid, the fungal hyphae penetrate to the cortical cells, which swell to form vesicles or arbuscules. So it is called Vesicular Arbuscular Mycorrhiza (VAM). It has significant role in phosphate nutrition of plants.

ECONOMIC BOTANY

CEREALS :

These are the members of family Gramineae and grown for their edible seeds.

(1) Wheat (Triticum aestivum) : - Wheat is the chief cereal used by man as food from ancient times. It is an annual grass and the inflorescence is a terminal spike consisting of 15-20 spikelets. The important varieties of wheat, grown in India are Kalyan sona, Sonalika, Sharbati Sonara, Lerma Rojo, Sonara 64 etc.

(2)  Maize(Zea mays) : - It is the second important cereal crop. Maize is a tall annual grass with height of 4 to 10 feet ; plants are monoecious. In India common varieties grown are Sona, Vijay, Jawahar, Vivek-8, Amber etc. The maize grains are very nutritious ; they contain high percentage of easily digestible carbohydrates, proteins and fats; the grains are also used in the manufacture of corn starch, glucose and alcohol ; also used as a chief food for livestock ; the fibre from stem and spathe is used in paper industry.

(3)  Rice (Oryza sativa) – Rice is the principal food crop of millions of peoples of the world. The rice plant is an annual grass having a height of 2-4 feet and produces a panicle, an inflorescence consisting of a number of fine branches. It grows best on damp soils, where it can be flooded . The rice grains are used as a food after cooking; stem, husk etc. are used as fodder; grain is also used in the manufacture of alcoholic beverages.     

(4)  Sorghum (Sorghum vulgare) : Sorghum is staple food for millions of peoples in Asia and Africa. It is a tall annual plant with a height of 6-12 feet; the stem is stout and the panicle much-branched. The grains are made into flour often mixed with wheat, forming a nutritious food. The plants are used as fodder, in the manufacture of brushes, syrup and also in the paper industry.

(5)  Barley(Hordeum vulgare) : - Barley is an annual plant with a height of 3 feet. The inflorescence is a spike; the grains may be white, purple or red and are covered with husk. Barley is used in the preparation of bread, cakes after mixing it with wheat flour ; straw is used as a livestock feed ; also used as a source of malt, used in the manufacture of beer, whisky, alcohol etc.

(6)  Pearl millet or Bajra (Pennisetum typhoides) : - It is cultivated almost throughout India. The plants attains a height from 6-12 feet and the dark-brown spikes, 15-25 cm in length occur in clusters. It is an important food for poor people in our country ; the flour is used for making chapatis ; the plants are also used as fodder.  

PULSES :

(1)  Pea(Pisum sativum) : - It is grown all over India during winter months. The plant is an annual herb climbing by means of tendrils. The seeds are eaten after cooking as vegetable; plants are used as valuable fodder.

(2)  Gram(Chana)(Cicer arietinum) : - It is cultivated all over India as an important pulse. The plant is a bushy annual and matures in about three months. The seeds are eaten as dal and the flour which is commonly called as besan is used in the preparation of sweets and other foodstuffs; the plants and seeds are also used as cattle feed.

(3)  Pigeon pea or red gram (Arhar) (Cajanus cajan) – It is widely cultivated in India and is grown as a pure crop or mixed crop. The plant is a perennial shrub. Dry grains are used as dal; leaves form a valuable fodder. Branches are used for making baskets.

(4)  Ground nut (Moongphali) (Arachis hypogea) : The plant is a bushy annual with underground fruits. Groundnuts are very nutritious as they are rich in proteins. Seeds are used after roasting for preparation of peanut butter ; groundnut oil is largely used as cooking oil.

(5)  Black gram (Urd)(Phaseolus mungo) : It is the one of the best pulses grown all over India. The plant is a trailing annual. It is used as Dal ; flour is used in the preparation of papads and biscuits ; seeds and straw form a valuable cattle feed.

(6)  Soya-bean(Glycine max) : - The seeds of this plant are the protein richest, natural vegetable food known. It is cultivated all over India. The plant is a small, bushy, erect annual. It has 30-60% protein content. Seeds are used, green or dry; soya milk, soya cheese etc. are prepared from the seeds ; soyabean flour is used in bakery, ice-cream etc.

(7)  Green-gram (Moong) (Phaseolus aureus) : - It is cultivated as an important pulse crop in Uttar Pradesh, Madhya Pradesh, Rajasthan, Bihar and Bengal. The green pods are eaten as vegetable and seeds are used as dal. The entire plant is used as cattle feed.

VEGETABLES :

Vegetables contain a large quantity of carbohydrates and mineral salts like calcium, iron, phosphorus, iodine etc. they are also rich in vitamins, therefore, are included in our daily diet. Some of the important vegetables are as follows : -

(1)  Potato (Solanum tuberosum-family solanaceae) : Main vegetable crop. It is an erect, branched annual ; tuber is modified stem, which have different shapes-round, oval and cylindrical ; it is a native of Peru (South America) and was first introduced in India by the Portuguese in the early part of the 17 century ; potato tubers are eaten as vegetable and in various other forms ; they are also used in the production of starch and industrial alcohol.

(2)  Tomato (Lycopersicon esculentum family Solanaceae) : - It is a native of South Asia ; it is cultivated in warm countries for its fruits, which are used as vegetable. Tomatoes are also used in the preparation of ketchup, sauce, soup and juice.

(3)  Brinjal (Solanum melongena-family solanaceae) : - It is an erect, branched, annual herb, fruit is large, ovoid, purple or whitish berry ; it is a native of India. The fruits are eaten as vegetable.

(4)  Okra (Bhindi) (Abelmoschus esculentus –family Malvaceae) : - It is an annual herb with yellow crimson centred flowers ; it is grown in warm countries for its mucilaginous fruits ; it is a native of tropical Africa. The fruits are used as vegetables and also in soup.

(5)  Onion (Alium cepa- family Liliaceae) :  It is a native of South Asia. The food is stored in the bulb; bulbs of onion are popular as vegetable and are also used for flavouring and pickling. The leaves are also eaten as vegetable.

SUGAR :

(1)  Sugarcane (Saccharum officinarum) : - It belongs to family Gramineae and is the chief source of sugar in India. The plant reaches a height of 6 to 12 feet and a diameter of 1 to 2 inches ; the stem is solid with many fibrous strands and contains juice ; the stems are cut close to the ground and are then sent sugar mills for the extraction of sugar. Molasses is used in the manufacture of rum and industrial alcohol.

(2)  Sugar-beet (Beta vulgaris) : It belongs to family chenopodiaceae and is the source of sugar in cold countries. The sugar-beet is a biennial herb with tap root. Sugar is extracted from the fleshy roots which contain 15-20% of sucrose.

FIBRES :

(1)  Cotton (Gossypium sp.-family malvaceae) : Cotton is the most important commercial textile fibres. It is used for a variety of purposes, especially in the manufacture of a large proportion of the clothing. Fibres are produced by the seed coats of various species of gossypium. Fibres are also used for making ropes, twines and threads ; raw cotton is also used for stuffing pillows and cushions.

(2)  Jute (Corchorus capsularis and C.olitorius – family Tiliaceae) : - It is a very valuable bast fibre and is second in use to cotton. The fibres are extracted by the process of retting in which the branches of plants are dipped in water for few days ; after retting fibres are separated. Jute fibres are used for making gunny bags, packing cloth, carpets, cordage, curtains etc.

(3)  Sunn hemp (Crotolaria juncea-family papilionaceae) : The plants are extensively cultivated in India. The long fibrous strands are made up of lignified phloem sclerenchymatous cells, which are obtained after retting. The fibres are used in manufacture of ropes, canvas, nets, cordages etc.

(4)  Flax (Linum usitatissimum-family Linaceae) : The fibres are very strong, silky, short in length and are formed in the pericycle of the stem. Flax fibres are used in the manufacture of linen cloth, carpets, canvas, cigarette paper, insulating materials etc.

(5)  Hemp (Cannabis sativa – family cannabinaceae) : The fibres are obtained from the pericycle after retting. The hemp fibres are long, strong and durable but lacks flexibility. It is used for the manufacture of ropes, cables, nets, canvas etc.

(6)  Munj (Saccharum munja-family Gramineae) : The fibres is obtained from the stem. It is used for making chair, tables, baskets, mats and ropes.

(7)  Coir (Cocos nucifera-Family palmae) : It is obtained from the fibrous mesocarp of the fruit ; the fruits are dipped in marine water for many months and then beaten to separate the fibres. Coir is used for making brushes, doormats, carpets, sacs, bags, cordage etc.

OILS :

(1)  Groundnut oil is obtained from the seeds of Arachis hypogea-Family Papilionaceae; refined oil is used in cooking and oil is converted into vegetable ghee by hydrogenation.

(2)  Gingelly or sesame oil is obtained form the seeds of Sesamum indicum- family Pedaliaceae ; oil is used in cooking, medicine, soap etc.

(3)  Coconut oil is obtained from the dry kernel of the seed of Cocos nucifera-family Palmae ; oil is used for cooking, hair oil and in the manufacture of soaps, shampoo, cosmetics etc.

(4)  Mustard oil is obtained from the seeds of Brassica campestris- family cruciferae ; oil is chiefly used for cooking purposes.

(5)  Castor oil is obtained from the seeds of Ricinus communis-family euphorbiaceae ; oil is used in medicines, as lubricant and also in making soaps.

(6)  Soyabean oil is obtained from the seeds of Glycine max-family Papilionaceae ; raw oil is used in the manufacture of soap, varnishes, paints etc, ; refined oil is  used for cooking purposes.

(7)  Linseed oil is obtained from the seeds of Linum usitatissimum-family Linaceae ; oil is used in making paints, varnishes, soaps etc.

TIMBER :

(1)  Indian Redwood (Sesham) (Dalbergia sisso- family Papilionaceae) : The wood is dark-brown in colour and is very strong and durable. It is used for making good quality furniture, carts, boats, etc.

(2)  Teak (Tectona grandis-family verbenacea) – It is the most important wood as it is extremely durable. It is used for making best quality furniture, houses, ship-building, for bridges, railway sleepers etc.

(3)  Deodar (Cedrus deodara – family Pinaceae) : - The wood is light, extremely durable, yellowish-brown in colour. It is used for house, building bridges, railway sleepers, light furniture etc.

(4)  Sal (Shorea robusta-Family Dipterocarpaceae) : - The timber is very hard, heavy, strong and very durable. The wood is of brown colour and is used for beams, furniture, carts, bridges, railway sleepers etc.

(5)  Mahogany (Swietenia mahogoni-family Meliaceae) – It is a valuable timber tree. The wood is very hard and durable and is used for, making boats, ships, furniture etc.

(6)  Toon (Cedrella toona-family Meliaceae) – The timber is very light and is used for making furniture, houses, packing boxes etc.

(7)  Mango (Mangifera indica-family Meliaceae) – The wood is strong, slightly lighter and gray or grayish-brown in colour. It is used for door and window frames, packing cases and tea boxes.

BEVERAGES :

(1)  Tea (Thea sinensis or Camellia sinensis-family Theaceae) : It is the most popular beverage ; Prepared from the dried leaves of this plant. The plant is now cultivated in China, India, Pakistan, Japan, Ceylon, England and Indonesia. The tea plant is a shrub of 3-4 feet high. The tea leaves are picked by hand which are processed for obtaining different grades of tea leaves.

(2)  Coffee (Coffea Arabica and C.robusta-family Rubiaceae) : Seeds of these plants are the sources of  coffee. The seeds are dried in sun or by artificial heat and then roasted to develop flavour, aroma and colour. Coffee plant is a shrub or small tree 16 to 25 feet high. Main coffee plantations are in the hill slopes of South India – Karnataka, Kerala and Tamil Nadu. It is the favourite drink all over India particularly south India.

(3)  Cocoa (Theobroma cocoa-family Sterculiaceae) – It is prepared from the seeds of this plant. The beans roasted in iron drums at a temperature of 125ºC to 140ºC. The seeds are finally ground to and oily paste to form the bitter chocolate. Sweet chocolate is made by adding sugar to the bitter chocolate. Cocoa tree is a native of tropical Central and South America.

RUBBER :

Rubber is obtained from the latex of Hevea brasiliensis-family Euphorbiaceae, which is the main source of commercial rubber. The latex is collected by tapping the bark, which is processed for obtaining final rubber. It is used as tyres, tubes, rubber sheets, insulation of electric wires etc. The majority of rubber plantations are in Kerala,Tamil Nadu and Karnataka.

ECONOMIC BOTANY-AT A GLANCE……

• Basmati rice is mainly cultivated in U.P. and Haryana in India.
• The millets were the first cereals to be domesticated.
• Highest cultivation and production of cotton takes place in China, 2^nd → USA, 3^rd → India. In India it is max cultivated in Gujarat.
• Highest cultivation and production of jute fibre is in West Bengal of India. India is the largest producer of jute.
• Brazil is the largest producer country of sugar cane. 2^nd → India
• About 80% of sugarcane of India is grown in North India (mainly in U.P.)
• India produces about 90% of gram (Chick pea) of the world.
• China is largest producer of groundnut (China > India)
• Richest plant food-Soyabean [36.5% protein, 17.5% fat]
• Largest wheat producing country is European Union.
• Botanical name of Pop-corn- Zea mays var. everta.
• Indian Grassland and Fodder Research Institute is located at Jhansi.
• The principal cereal crop in India is-Rice.
• Botanical name of Indian rye-Brassica juncea.
• Centre of origin of rice-India. [South-East Asia.]
• RR-21 is high yielding variety of wheat.
• Cereals are major source of carbohydrate.
• Margarine' is prepared from Groundnut.
• Sugarcane Breeding Research Institute (SBRI) is situated at coimbatore.
• Fish net is prepared from Linum usitatissimum.
• The largest fibre crop of East India is-Jute.
• Jute Agriculture research institute (JARI) is situated at Barrackpore (west bengal)
• Commercial jute is morphologically bast fibre.
• Largest newspaper industry is situated at Nepanagar.
• Long fibres of cotton seeds are known as lint.
• The coir industry in India is concentrated in Kerala.
• ‘Gingelly oil’ or ‘Til oil’ is obtained from the seeds of Sesamum indicum.
• In ground nut (Arachis hypogea), oil is stored in cotyledons.
• Essential oils are those which are used in perfumes
• Highest sugarcane crop is grown in the world in Brazil. 2^nd → India.
• Industrial toxicology research centre situated at Lucknow.
• ‘Metha Jahar’ which is useful in rheumatism is obtained from Aconitum napellus.
• Chhattisgarh is also known as ‘Dhann Ka Katora’.
• Central Drug Research Institute is situated at Lucknow.   
• Isbgol is obtained from seeds of Plantago ovata.
• LSD is obtained from Claviceps.
• IARI, New Delhi is main centre of wheat breeding and research in India.
• Centre of origin of arhar/pigeon pea (Cajanus cajan) is south-east Asia.
• Centre of origin of groundnut is Brazil.
• Rabi crops are those, which grows in winter eg-wheat, Gram, Barley.
• Kharif crops are those, which grows in summer eg-Maize, Bajra, Moong.   
• 95% of the world crop of red gram (pigeon pea) is produced in India.
• India is the largest producer of cardamon.
• Oat (Avena sativa) is the most nutritious among all cereals, because of their high fat, protein and mineral contents.
• Russian federation > Canada > USA leads the world in production of oats.
• Urease enzyme is obtained from arhar/pigeon pea/ red gram/Cajanus cajan is used in estimation of urea in urine and blood.
• India is the largest exporter of jute and jute products. 
• Jute is a bast fibre and obtained from the secondary phloem.
• Max. Production of Tea-China > India.
• Essential oils or volatile oils are those, which evaporate in contact with air and have a pleasant fragnance.
• Banana (Musa paradisiaca sub sp-sapientum, fam-musaceae) : It is one of the oldest fruit called ‘Adam's fig’ and ‘apple of paradise’. Banana is the cheapest energy rich fruit having high content of carbohydrates, some fats and proteins.
• Mango (Mangifera indica, fam-Anacardiaceae) : It is good source of vitamin A, C and K.

COAL & PETROLEUM PLANTS :

Chemically petroleum is a liquid of varying composition. Kerosene, gasoline, benzene and paraffin are some important petroleum products. Melvin Calvin was first to identify few petroleum plants - the plants whose products can be used in place of petrol and oil. Most of such plants belongs to families-asclepiadaceae, euphorbiaceae, and apocynaceae. These plants are able to convert a substantial amount of hydrocarbon into latex. Euphorbia lathyrus contains a mixture like terpene, which can be converted into gasoline.