Technology

Economically viable technologies developed

1. Mixed bioinoculant - Azophos
2. Sugarcane biofertilizer – Gluconacetobacter diazotrophicus
3. Liquid biofertilizers
4. Arbuscular mycorrhizal biofertilizer production by rural women
5. Quality standards for AM biofertilizers
6. Microbial consortium for vegetable crops
7. PPFM

1. Mixed bioinoculant - Azophos

Azospirillum and phosphobacteria are the most popular and effective biofertilizers widely applied to all the agricultural and horticultural crops.  Azospirillum is able to colonize the roots of the crops and fix the atmospheric nitrogen to the tune of about 25-30 kg N per ha.  Similarly, phosphobacteria can able to solubilize the insoluble form of phosphates to soluble forms and make available to crops to the tune of 15-20 kg per ha per season.  Both these biofertilizers are applied as combined inoculant to the crops as seed treatment, seedling dipping and soil application and nursery treatment to supplement/support nitrogen and phosphorus respectively   Instead of two different packets of these biofertilizers mixed at the time of application, single inoculant packet containing both these organisms as mixed inoculant was developed and named as Azophos.

 Advantage

The main advantage of Azophos is to ensure the application of both the important inoculants without missing any one of them.

 Method of application

Five or ten packets (1 to 2 kg) of Azophos for seed treatment (depending on the seed size) and seedling dip; Twenty packets (4 kg) for nursery application and main field application are recommended for one acre.   For tree crops, 100 g of Azophos is recommended once in six months.

 Impact of this technology / Adoption

• After release of this technology, several front line demonstration trials were conducted at Coimbatore, Erode and Salem districts.  The results revealed that Azophos application registered 20% yield increase over the fertilizer control, which satisfied the farmers to adopt this technology.
• Azophos mixed biofertilizer sale in the Department of Agrl. Microbiology has been increased gradually since its release.

Coverage was calculated based on average biofertilizer application at 4 kg/ha

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• The farmers of Coimbatore, Erode and Salem, approaching the Department of Agrl. Microbiology are presently supplied with Azophos instead of two separate biofertilizers.  The farmers belong to Palani, Coimbatore, Madurai, Salem, Erode districts purchased Azophos for variety of crops like rice, maize, tomato, coconut, brinjal, flower crops etc.
• The KVKs of TNAU like Yethapur, Thindivanam, Madurai are presently distributing Azophos for their farmers as input.

2.   Sugarcane biofertilizer - Gluconacetobacter diazotrophicus

In general, Azospirillum is the common biofertilizer recommended for N nutrition which could colonize the roots of sugarcane and fix atmospheric nitrogen to the tune of about 50 to 75 kg nitrogen per ha per year.  Recently, another endophytic nitrogen fixing bacterium, Gluconacetobacter diazotrophicus isolated from sugarcane can able to fix more nitrogen than Azospirillum.  It colonizes throughout the sugarcane and increases the total N content.  In soil, it can also colonize the roots and able to solubilize the phosphate, iron and Zn.  It can also enhance the crop growth, yield of sugarcane and Sugar content of the juice. Since it is more efficient than Azospirillum, this new organism was test-verified in various centres and released as new biofertilizer Gluconacetobacter diazotrophicus – TNAU Biofert-I.

Advantages

This biofertilizer is more effective than Azospirillum for sugarcane.  It can able to solubilize many macro and micronutrients like P, Zn, Fe etc.  It also showed antogonisitic activity against soil pathogenic fungi.

Method of application

Ten packets (2000 g) per ha of Gluconacetobacter diazotrophicus prepared as slurry with water can be used for sett treatment.  Twelve packets (2400 g) per ha is recommended for soil application each at 30^th, 60^th and 90^th day after planting.

Impact of this technology / Adoption

• Gluconacetobacter biofertilizer is being popularized among the sugarcane farmers by Front line demonstration trials were conducted at Erode, Coimbatore, Vellore and Tirunelveli districts.  An average yield increase of 8 to 10 % over fertilizer control was noticed.  Further, sugar mills producing and supplying biofertilizers to their farmers were advised to use these efficient mother cultures. Accordingly seven sugar mills and private agencies bought the mother cultures from TNAU for and mass producing Gluconacetobacter biofertilizer and distribution to their farmers.  Further, Pondicheery Co-operative Sugar Mills, are regularly purchasing inoculant packets from this department and distributing to their contact farmers. 
• The firms got the mother cultures of Gluconacetobacter from TNAU:
  • M/S Bannari Amman Sugar mills, Sathi
  • Indian Tobacco Corporations, Hyderabad
  • KCP sugars & Industries, Krishna
  • Amaravathy Co-operative Sugar mills, Udumalai
  • Rajashree Sugars Ltd, Theni
  • Natural Agri World, Paramathi vellur
  • Ioliage Chemicals, Chennai

• Carrier based Gluconacetobacter sale in the Department of Agrl. Microbiology and various sugar industries have been increased gradually since its release.

Coverage was calculated based on average Gluconacetobacter biofertilizer application at 5 kg/ha

3.  Liquid formulation of biofertilizers

Presently, biofertilizers are prepared as carrier based formulations and lignite is the most widely used carrier material.  The improper sterilization of carrier material and handling while mixing the bacteria with carrier and packing serve as source of contaminations.  Because of this, the inoculant pocket could not hold desired biofertilizer organism for long time, which reduced the shelf-life of the biofertilizers.  Further, the quality of the biofertilizer gets deteriorated.  Because of these reasons, biofertilizer application could not able to give viable results in the fields.  To avoid these and to increase the quality and shelf-life of bioinoculants, liquid formulation of Azospirillum and phosphobacteria was developed.  Preservatives were added with the bacterial cultures and packed in quality PP bottles.  The shelf-life of liquid inoculants is one year, which can hold the cell count of more than 10⁸ per ml without any contaminants. 

Advantages

The liquid inoculants have higher quality, longer shelf-life without contaminants than carrier based inoculants.  The performance of liquid inoculants in the field is on par with conventional carrier based inoculants. 

Method of application

Seed treatment – 250 ml each Azospirillum and Phosphobacteria per ha seeds; Seedling dip – 500 ml each Azospirillum and Phosphobacteria per ha seedlings; Soil application - 500 ml each Azospirillum and Phosphobacteria per ha seedlings; Tree crops – 100 ml each Azospirillum and Phosphobacteria per tree once in six months.

 Impact of this technology / Adoption

• Liquid formulations of Azospirillum and phosphobacteria were mass produced in large quantity and supplied to farmers of Coimbatore district through National Horticulture Mission.  The major beneficiaries are farmers growing Goose berry, chillies, turmeric, and mango like horticultural crops.
• The liquid biofertilizers produced and supplied last year by TNAU are tabulated below:

            Coverage was calculated based on average application at 500 ml/ha

4.      Arbuscular mycorrhizal biofertilizer production by rural women

Arbuscular mycorrhiza (popularly called as VAM) is an important fungal biofertilizer for nursery and horticultural crops.  They are obligatory symbiotic organism, colonize the roots and form symbiotic structures in the roots of all the plant species.  Application of AM enhances the mobilization of P and uptake and also induces the resistance to the crops against fungal pathogens.  As large quantity of inoculum is required, AM biofertilizer is not recommended for direct sowing.  AM is highly suitable for nursery based crops like vegetables, ornamental seedlings and also for tree crops.  Presently, AM biofertilizer is mass multiplied in vermiculite based maize and sorghum root.  The AM colonized root bits, spores and other infective propagules are mixed with vermiculite carrier and supplied to the farmers with a keeping quality of 1 year.  This simple mass production technique developed by TNAU is amenable for multiplication by farmers themselves for their own use.  Since the AM biofertilizer requirement is huge and more over TNAU and few private companies are the only producers in Tamil Nadu, there is a wide scope for the women self help groups to take up this venture for economic benefits.  Hence farm women groups in various districts were given intensive training on the production of this biofertilizers.

 Advantages

With adequate knowledge, AM biofertilizer can be produced by the rural women and made available for their village farmers.  It also increases the net income of the rural families (Fixed cost - Rs. 7500; Working capital – 10,000/year; Net benefit – 10,000 for I year; 20,000 from II year on words.  

Impact of this training / Adoption

• Awareness of AM biofertilizer was created among the farm women and self help groups.
• About 819 women of Coimbatore district were benefited for the last three years due to intensive trainings on AM biofertilizer.
• A total of 15 successful AM biofertilizer production units are in operation after the training with the average production outlet of 1600 – 2000 kg per year.
• Income generation of Rs. 24,000 – 30,000 per year from a AM biofertilizer unit is achieved.
• Linkage with NGOs like Santhi Ashram, NERD society, AME foundation, M/S Swaminathan Research Foundations, MYRADA were developed for AM mass production training which widen the spread of this technology.
• The mass production of AM biofertilizer at TNAU also boosted due to this awareness and generated high income. 

Coverage was calculated based on average application at 10 kg/ha

5.  Development of mycorrhizal biofertilizer quality standards

Mycorrhizal biofertilizers are presently multiplied in vermiculite based inoculum containing infective propagules produced in maize roots.  Since AM biofertilizer is multiplied in maize beds, developing quality standards under this condition is essential to serve as biofertilizer.  For this, two quality standards assessed as follows:

• AM Infected root bits – A minimum of 75% AM infected root bits should be observed from sample
• Spore load – A minimum of 30 spores per 100 g of sample (by wet-sieving and decanting method)

6.  Methylobacterium biofertilizer

Methylobacterium is a plant-associated bacterium, popularly called Pink-Pigmented Facultative Methylotrophs (PPFMs) present in the phyllosphere and rhizosphere of most of the crop plants.  The association of Methylobacterium species with plants seems to rely on a symbiotic relationship between the bacterium and host plants. Most common niche for synergism between Methylobacterium and plant is the phyllosphere, where they utilize methanol evolved from leaves as the sole source of carbon and energy and in response, methylobacteria produce phytohormones like cytokinin and auxins.  Hence, this plant associated beneficial bacteria was test verified as bioinoculant in several crops proved to enhance the crop growth and yield.  This growth hormone producing bacterium combined with Azospirillum and Phosphobacteria, a microbial consortium is prepared and designated as Azophosmet.  This biofertilizer technology was adopted in Crop Scientist Meet-2009.