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 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.,

  1. Symbiotic micro-organism e.g. Legume –Rhizobium, Symbiosis

  2. Asymbiotic or free living e.g.Azotobacter, blue green algae.

  3. 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 don’t 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.