Agrobased Industry
Introduction:
An atmosphere around us contains nearly 78% nitrogen which is in free form. Hence it is
not available to plants. At present, India produces around 190 million metric tonnes of
foodgrains for its growing population of 100 crores. In order to meet the food
requirements of ever increasing population, the nitrogen fertilizer requirement for crop
production by 2000 A.D.is roughly estimated to be 11.4x106 tonnes. Increased foodgrain
cannot be produced unless we carefully make use of biological nitrogen. Biological
nitrogen fixation is the key to sustain agricultural productivity through the application
of biofertilizers in the field . However, there is an urgent need to transfer this
technology on the field of a farmers and into an industry by producing these fertilisers
on large scale.
What is
biofertilizer?
It is
living fertilizer compound of microbial inoculants or groups of micro-organisms which are
able to fix atmospheric nitrogen or solubilize phosphorus, decompose organic material or
oxidize sulphur in the soil. On application, it enhances the growth of plants increase in
yield and also improve soil fertility and reduces pollution.
There are
variety of nitrogen fixing micro-organisms present in the nature. These are broadly
divided into three categories, viz.,
Symbiotic
micro-organism e.g. Legume Rhizobium, Symbiosis
Asymbiotic
or free living e.g.Azotobacter, blue green algae.
Associative
Symbiosis, e.g.Azospirillum
These
micro-organisms supply in addition to nitrogen, considerable amount of organic matter
enriching structure of soil. Inoculants of these micro-organisms have proved their
technical feasibility, economic viability and social acceptability. They are therefore
called as `biofertilizer. Hence the term `biofertilizer or microbial
inoculants may be defined as preparations containing living or latent cells of efficient
strains of nitrogen fixing, phosphorous solubilizing or cellulolytice micro-organism.
Need for
biofertilizers: Biofertilizers have definite advantage over chemical fertilizers. Chemical
fertilizers supply over nitrogen whereas biofertilisers provide in addition to nitrogen
certain growth promoting substances like harmones, vitamins , amino acids, etc., crops
have to be provided with chemical fertilizers repeatedly to replenish the loss of nitrogen
utilised for crop growth. On the other hand biofertilizers supply the nitrogen
continuously throughout the entire period of crop growth in the field under favourable
conditions. Continuous use of chemical fertilisers adversely affect the soil structure
whereas biofertilizers when applied to soil improve the soil structure. The deleterous
effects of chemical fertilizers are that they are toxic at higher doses. Biofertilizers,
however, have no toxic effects.
It may be
borne in mind that biofertilizers are no substitute for chemical fertilizers. At present,
the use of chemical fertilisers is far below the recommended level. Therefore, the aim and
object of spread of biofertilisers technology as a Industry has to build up efficiency in
use of chemical fertilizers supplemented by low cost inoculants to the extent possible.
Main
constraints in spread of biofertilizers as an Industry are production and supply of
efficient cultures of micro-organisms to farmers well before sowing. Secondly, Quality
control aspect and lack of publicity, etc. At present, in Maharashtra there are roughly 45
entrepreneurs located mostly in cities of which very few have qualified staff and
facilities for production of biofertilisers. In order to cover the vast areas of legumes,
pulses and oil seeds and cereals, horticultural crops we need more manufacturers who can
prepare the biofertilisers in particular locality and supply to farmers as per their need.
Besides,
whatever biofertilizers are prepared are not reached to farmers prior to sowing. At many
places they are given free of cost, which lowers down the importance of product and
farmers dont use them carefully. Sometimes, biofertilisers are supplied after expiry
date and hence expected results are not obtained.
A quality
control aspect is the most important in biofertilizers. Now-a days most of the
products sold in the market are below standard. A few entrepreneurs possess ISI mark for
their products. The government have no control over manufacturers of biofertilisers in any
of the states of India. There are no rules and regulations related to production and sale
of biofertilisers in Maharashtra. Hence farmers are confused about rates, quality and
expiry dates of biofertilisers. Similar is the case of prices; they are varied from place
to place.
Followings
are some of the important types of biofertilisers which can be considered for agrobased
industries.
Rhizobium
biofertilisers: Rhizobium bacteria in Association of legumunious plants fix atmospheric
nitrogen in nodules formed on the roots of plants. These nodules are considered as
miniature nitrogen production factories in the field. A pure and efficient strain of
Rhizobium can be multiplied in the laboratory on a suitable medium by using shake
technology or fermentation technology.
Azotobactor
biofertiliser: Azotobacter are free living micro,organisms, and they grow in the
rhizosphere and fix atmospheric nitrogen non-symbiotically and make it available to
particularly cereals. In addition, these bacteria produce growth promoting substances
thereby enhancing the plant growth and finally yield. A highly efficient strain of
Azotobacter is grown in the laboratory either as shake culture or using fermenter.
Azospirillum
Biofertilisers: They are called as associative endosymbiont on roots of grasses and
similar types of plants. They are also known to fix atmospheric nitrogen and benefit host
plants by supplying growth hormones and vitamins. These bacteria are commonly used for
preparation of commercial inoculants on a large scale using common technique.
Blue
green algal biofertilisers: Blue green algae are considered as an important group of
micro-organism capable of fixing atmospheric nitrogen non-symbiotically mostly in rice
fields in heterocysts cells specially known as sites of nitrogen fixation. There is
variation between species of blue green algae in fixation of nitrogen and other qualities
of biofertilizers. Efficient strains of blue green algae are used for multiplication on a
large scale. Production of inoculum in artificially controlled conditions is defined but
more expensive. On the other hand open air soil culture is most simple, less expensive and
easily adaptable by the farmers. This is based on use of starter culture that is
multistrain inoculum of Aulosira, Tolupothrix, Scytonema, Nostoc and Anabaena. This is
paying industry in rural areas and unskilled labour can also undertake the multiplication
of blue green algae.
Azolla
Biofertilisers: Azolla is a water fern inside which grows the nitrogen fixing blue green
algae Anbaena. It contans 2-3% nitrogen when wet and also produces organic matter in the
soil. This type of biofertiliser is used all over the world. This can be grown in a cooler
region. But there is a need to develop a strain tolerant to high temperature, tolerant to
salinity and strains resistant to pests and diseases. Production technology is very easy
and can be adopted by rice farmers. The only constraint in Azolla is that it has to be
kept always growing on water and water becomes limiting factory particularly in summer
since viability of Azolla seeds is very poor. Phosphorus-solubilizer (Biofertiliser) :
Phosphorus is one of the important elements required for plant growth and water yield.
This element is also essential for nodulation by Rhizobium. Phospho-micro organism are
most bacteria and fungi are used for commercial purposes mycorrizae have high potential of
phosphorus accummulation in plants. There are two types of mycorriza viz :endo and
ecto trophics. VA mycorrhiza are most popular and used for commercial purpose. In general,
it will be seen from above information that biofertiliser manufacturing is a budding
industry and need some more years to establish variable.
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Ag.
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