Biofertilizers in NE region
In NE India, Assam was the first state to realize the importance of biofertilizers during early seventies when a few kilogram of Rhizobium and blue green algae (BGA) inoculants were brought from other states and used in departmental demonstrations. Assam Agricultural University (AAU), Jorhat initiated the evaluation of various strains of Rhizobium and BGA and started producing little quantities in the late seventies. Combined efforts of AAU and Department of Agriculture, Assam have finally proved their positive potential and led to the establishment of two production units during 1980-81-1982-83, one under Assam Agro Industries Development Corporation Ltd at Khanapara, Guwahati, Assam and another at Department of Soil Science, AAU, Jorhat.Among other states in NE region of India, Arunachal Pradesh and Meghalaya introduced biofertilizers during 1984-85, followed by Manipur and Sikkim in 1978-88. Tripura introduced the biofertilizers for the first time in 1988-89. Mizoram and Nagaland had introduced the regular uses of biofertilizers after 1994-95.Having established the positive role of Rhizobium on improvement of pulses through systematic research, it was intended to produce Rhizobium biofertilizer for increasing the yield of pulses grown by the farmers of Assam. Research results were submitted to the North-Eastern Council (NEC) which later on funded a biofertilizer centre started at AAU in 1983 to cater to the need of bacterial biofertilizers for the entire NE region of India. Under the biofertilizer production programme few research works were carried out by post graduate students of AAU, Jorhat. Though few efficient strains were isolated and characterized, these strains could not be used for biofertilizer production due to termination of the financial assistance from NEC in 1991. This plant funded by NEC continued production of Rhizobium biofertilizer packet to meet demand of farmers of entire NE states until 1991. During the period of 1983 to 1991, the biofertilizer production centre produced total of 20,000 packets of Rhizobium cultures and earned revenue of rupees 15 lakhs (official record). In a post graduate research work leading to Ph.D. degree under this programme, 350 Rhizobium strains in root nodules of pulses such as green gram, black gram, arahar, pea, lentil, gram and legumes such as soybean grown under the seven agro-climatic zones of Assam were isolated. These isolates were screened through a series of laboratory and green house studies and finally a few top ranking isolates were selected for use as inoculums for seven pulse crops of the state. These isolates were MR27 and MR48 for green gram, BR5 and BR16 for black gram, AR26 for arahar and PR27 and PR12 for pea, LR17 for lentil, GR28 for gram and SR18 for soybean (Das, 1990).Screening and utilization of indigenous Azospirillum, phosphate solubilizg bacteria (PSB) and fluorescent pseudomonas started since 1998 under a Department of Biotechnology (DBT), GoI sponsored project from rice rhizosphere from the central Brahmaputra Valley Zone of Assam. Based on morphological and biochemical characters, the Azospirilla were tentatively identified A.lipoferum, A. brasilense and A. amazonense. Eight PSB were isolated based on thickness of clearing zone (0.97-3.10mm) in agar. Similarly, eleven Pseudomonads were isolated from rice rhizosphere soil. The Azospirillum, PSB and Pseudomonads were evaluated on ahu and sali rice during 2000.
Potential biofertilizer requirement in Assam and other north eastern states
In 1995 and 2001, efforts were made to eastimate the total potential requirements of biofertilizers in Assam and other north eastern states. As per Bhattacharya and Mishra (1995) if the entire cropped area of the region were to be inoculated with biofertilizers then the total requirement of the bacterial biofertilizers would be 7166 MT and of BGA biofertilizers would be 19187 MT. As per the estimates of Dwivedi and Motsara (2001), if only 50% of the total cropped area is brought under biofertilizer use then there will be a total requirement of 2540 MT of bacterial biofertilizers and 9901 MT of blue green algae (BGA) biofertilizers. In Assam alone total bacterial biofertilizers requirement is estimated to be of 5474.4 MT and 14319.4 MT of BGA biofertilizers for the entire cropped area. Likewise to inoculate the achievable 50% of total cropped area, 1798 MT of bacterial and 7510MT of BGA biofertilizers will be required for Assam.Compared to Indian averages, Assam and NE region have witnessed very slow decadal growth of biofertilizers production and their uses. In Assam, the solid biofertilizer produced during 2002-03 was only 57 MT which was increased to almost double at 130MT in ten years (2011-12). However, in next decade (2011-12 to 2022-23) the uses of biofertilizer increased by 228%. The total solid biofertilizer produced during 2022-23 was 427MT. The liquid biofertilizers produced at Assam was 3477KL (NCOF, 2022-23) which is only 0.62% of Indian total.In the vision document of Assam Aricultural University, it is projected that out of 17 lakh ha area under sali rice in the state, 10 lakh ha area is earmarked for high yielding varieties (HYV) and 2 lakh ha area under aromatic and other specialty rice in organic mode of production (Vision 2050). Similarly, 4 lakh ha is of summer/autumn rice earmarked for HYV. Considering 3.5kg of biofertilizer consortium as component of INM/organic mode of production, the total requirement of biofertilizer consortium for 16 lakh ha area would be 5600 MT/yr by 2050. In a phase wise conversion, if only 50 % of the area is brought under INM/organic mode of rice production, at present the total requirement of biofertilizers would be 2800MT/yr. Together for pulses and oilseeds, for an area of 4.31 lakh ha, the total requirement of biofertilizers would be 1508 MT/yr. In case of organic agriculture, University initially plans to convert 2.75 lakh ha exclusively under organic agriculture which would require 962MT of biofertilizers per year and projected to cover 9.63 lakh ha by 2050 requiring 3368MT of biofertilizers. To inoculate this achievable potential, the total requirement of biofertilizers would be 5270MT in each year against the present production of 427MT (8%) (NCOF, 2022-23 Annual Report). There is a huge gap between demand and supply of biofertilizers for Assam alone.The Indian biofertilizers market volume is worth $110.07 million in 2022 and is expected to grow to $243.61 million by 2029, exhibiting growth of 12.02%. Under this scenario, the contribution of biofertiizer production and uses in Assam is only 0.13% and 0.62% for solid and liquid biofertilizers respectively. From existing production of427 MT/yr and liquid biofertilizer of 3477KL/yr and anticipated potentiality (5270 MT/Yr) of biofertilizer use in Assam, there is tremendous scope to increase the production capacity of biofertilizers in public-private partnership (PPP) mode. With a production capacity of 100-150MT/yr, there is ample scope for setting up of 25-30 biofertilizer production units in the state for employment generation.
AINP on Soil Biodiversity-Biofertilizers
The AINP on Soil Biodiversity-Biofertilizers was implemented from November 2004 at Assam Agricultural University (AAU) with a mandate to exploit the beneficial microbes from the rhizosphere of different crops grown in the Assam and their uses in combinations with the existing available bio-resources at hand. The functioning of the project at AAU has strengthened the research and development on biofertilizers in the region and greatly expanded the horizon of biofertilizers. Some of the most important accomplishments are discussed below.The advent of biofertilizers including both carriers based and liquid biofertilizers have provided manifold solutions and have shown promising results in agricultural sustainability. On these perspectives, the AAU centre have effectively screened and evaluated the efficient biofertilizer microbes from the pristine ecosystems of the region.
Rhizobia Research: A detailed survey was undertaken in 5 agro-climatic zones of Assam to authenticate the areas where different pulse crops were cultivated. Altogether, 55 cultures of Rhizobia were isolated during the years 2004- 05,2005-06 and 2019-20 from the nodules of 7 pulse crops (Field pea, Lentil, Green gram, Black Gram, Cowpea, Rajmah and Lathyrus ) grown extensively in these areas.
Azotobacter Research: A Study was undertaken to exploit prospective Azotobacter from the crop rhizosphere of Assam. Based on the nitrogenase activity, twelve Azotobacter isolates representing rhizosphere samples from rice, toria and wheat were isolated in Burk’s media using classical technique. All the twelve isolates were shown to produce pigments, exopolysaccharides, IAA and GA at varying degrees. However, only seven isolates could produce siderophore and five of them could HCN. Five isolates (Azo03, Azo05, Azo08, Azo25 and Azo52) showing production of IAA, GA, siderophore and HCN were further evaluated for biochemical traits and intrinsic antibiotic resistance (IAR) potentials. The isolates differed specifically in assimilating different carbohydrates and IAR profiles. The isolates showed decarboxylase activity and ferment citrate as sole carbon source and therefore could established high activity in the rhizosphere.
Azospirillum Research: Eighteen Azospirillum cultures isolated from rhizosphere of rice were subjected to efficiency test. Ten cultures selected on the basis of ARA, IAA production including biochemical tests.
Phosphate Solubilizing Bacteria: An exhaustive study was undertaken to harness prospective phosphate solubilizing bacteria (PSB) from cropped rhizosphere of Assam. Overall 27 PSB isolates representing rhizosphere samples were isolated, screened and evaluated on Pikovskaya’s solid as well as in liquid media. The degree of tri-calcium phosphate (TCP) solubilization ranged from 7.33 to 59.66% among individual cultures. The isolated PSB63 from rice rhizosphere and PSB5W from toria rhizosphere were regarded as excellent P-solubilizer that recorded as high as 59.66% coupled with maximum drop of pH to 3.98 and 4.86 respectively from neutral. The isolates differed specifically in assimilating different carbohydrates. However the entire test isolates showed decarboxylase activity and could ferment citrate as sole carbon source and therefore established high activity in the rhizosphere. Subjecting individual isolates to six antibiotics with a range of concentration (50-1000ppm) also affirmed the possibility of strain variation amongst PSB isolates. Five phosphate solubilizing bacteria PSB5Y [MW301145; Bacillus circulans], PSB56 [MW301146; Bacillus circulans], PSB19 [MW301150; Bacillus proteolyticus, PSB25W [MW341420; Paraburkholderia tropica ] and PSB5W [MW341419: Paraburkholderia tropica] were identified using 16SrRNA gene amplification and sequence analysis.
Potassium Solubilizing Bacteria: The potash solubilizing bacteria isolated from crops rhizosphere of North Eastern region of India were identified by 16SrRNA (1500bp) sequencing as Serratia liquifaciens, Bacillus paramycoides , Bacillus proteolyticus Bacillus ceresus, Klebsiella variicola and Klebsiella spp. The primary mechanisms involved for K solubilization are drop of pH and release of polysaccharide were observed on inoculation of KSB in Aleksandrov broth (mica@0.5%) with reference to the control. The release of K from mica with drop of pH was ascertained by adjusting the media pH without inoculation of KSB.
Zinc Solubilizing Bacteria: The prospective Zn solubilising bacteria (ZSB) screened from Zn deficient paddy soils of Northeastern region of India to assess their ability to solubilize insoluble Zn compounds. Thirteen ZSB were recovered following the qualitative assay for clear halo formation and Zn solubilisation index (ZSI) in modified Pikovskaya’s solid plates containing ZnO (0.12%) and Zn3(PO4)2 2H2O (0.22%) separately. 16SrRNA gene amplification and sequence analysis were used to identify five bacterial isolates with a high capacity to solubilize ZnO. These isolates were identified as Bacillus subtilis, Pseudomonas putida, Pseudomonas aeruginosa, Paraburkholderia tropica and Bacillus circulans. The isolate Bacillus subtilis ZSBK95, in the present study illustrated significantly maximum clear halo (38 mm) formation, ZSI (4.22) and cumulative release of DTPA-Zn (205.56 µg mL-1) in the medium containing ZnO. A significant (p< 0.05) drop in pH (5.07-6.10) from the initial value (pH7.0) was observed in all ZSB isolates during the incubation period, along with a corresponding release of DTPA-Zn. Additionally, a strong negative correlation (-0.838, n=56, p≤0.01) was observed between the pH of the broth and Zn solubilization. The results indicate that the five identified ZSB isolates have a high potential for application as biofertilizers in Zn deficient paddy fields.
Actinobacteria Research: Culturable endophytic actinobacteria were isolated from different varieties of rice plants using specific Starch Casein Agar (SCA) media. Nine isolates showed antimicrobial activity against the pathogenic fungi viz. Fusarium oxysporum, Ralstonia solani, Curvolaria lunata and Sclerotinia sclerotiorum.Five isolates showed high inhibition against two important plant pathogenic bacteria Xanthomonas oryzae and Erwinia sp.The16SrDNA sequences of the efficient culturable endophytic actinobactrial isolates were related to Streptomyces longispororuber, Streptomyces rochei, Streptomyces parvulus, Streptomyces warraensis and Nocardiopsis alba.
Bacillus thuringiensis: The study under the project (DBT Twinning) indicated the presence of Bacillus thuringiensis in both agro ecosystem as well as forest ecosystem of surveyed districts of north eastern region. The frequency of B. thuringiensis colonies recovered on nutrient agar solid media ranged from 13.04 to 37.03% distributed across varied ecosystems on an average of 21.96%. Out of total 186 native Bt strains, 13 strains were shortlisted for Spodoptera litura and 18 strains for Helicoverpa armigera on the basis of single dose feeding bioassays against neonates of these test insects. The reference strains Bt kurstaki (HD-1) shown very high LC50 (320 µg g-1 of diet), against S. litura as compared to H. armigera (LC50=4.3 µg g-1 of diet), Till date there is no commercial Bt formulation found to be effective against S. litura as compared to H. armigera. In this project three native Bt strains J11C5 (LC50=21 µg g-1 of diet), G20W (LC50=26 µg g-1 of diet) and S5C3 (LC50=29 µg g-1 of diet) showing potential for developing biopesticide formulation for S. litura. On the basis of LC50 values, S5C3, S25C1 and J11C5 found to be effective against both S. litura and H. armigera. Some of the Bt strains isolated from forest ecosystem was found to be as effective as strains isolated from rice ecosystem and tea ecosystem in terms of insecticidal activity as they ≥ 50% mortality against neonates of B. dorsalis. The PCR based characterization of the putative Bacillus thuringiensis illustrated the presence of cry genes. Of the 167 isolates examined exhibited the existence of cry2, cry3, cry4 and cry9 genes. Few isolates also displayed the presence of multiple cry genes. The isolates J7C5, Soil20WR, Soil18C4, J11C5, J10C3, J11C3, J2R2, D4C1, S6C3, J11C1, J7W and J6C4 exhibited the presence of Cry proteins to the tune of 42-158kDa.
Pink Pigmented Facultative Methylotrophs: In the exploratory work, pink pigmented facultative methylotrophs (PPFM) were screened from phyllosphere of different crops of NE, India. PPFM under genus Methylobacterium colonize leaf surface and exhibits plant growth promoting (PGP) characteristics. In the study, leaf imprinting and serial dilution technique were used for isolation of PPFM from common vegetables and rice. A total of 45 PPFM isolates were screened, out of which 11 isolates were selected based on the quantitative estimation of nitrogenase enzyme activity and indole acetic acid (IAA) production. The selected PPFM isolates exhibited in vitro nitrogenase enzyme activity in the range of 0.59-1.30η moles of C2H4 mg-1 protein h-1, IAA in the range of 3.47-18.66µgmL-1 of culture filtrate, gibberellic acid (GA) in the range of 8.47- 20.57 µgmL-1. Five isolates, viz., PPFM4, PPFM6, PPFM9, PPFM10 and PPFM11 showed siderophore activity, while four isolates-PPFM3, PPFM4, PPFM10 and PPFM11 showed hydrocyanic acid production. All PPFM isolates showed varying response to common antibiotics and few could solubilize insoluble phosphorus and zinc. The selected isolates responded differently to all the biochemical tests like casein hydrolysis, nitrate reduction, urease, citrate utilization and starch hydrolysis. The research work showcased the existence of wide array of PPFM as leaf inhabitants of different vegetable crops and rice which exhibited varied PGP traits, and thus could be utilized for formulation of microbial inoculants after crop validation.
Microbes from Polluted Sites: Twenty-six bacteria isolated from coal, petroleum oil, brick, cement and paper mill polluted sites were identified through sequencing of 16S rRNA gene [using the bacterial primers (8F and 1406R)] and utilized for bioremediation of the particular polluted sites as microbial consortia formulation.
Collemboan Research: The pristine soils of NE India had the highest population of collembolan (4783 no sqm-1) followed by fallow land (3192 no/sqm) which decreased substantially in agro ecosystems (2418 no/sqm).The highest percent survival rate of mass multiplied collembolan was recorded in farm yard manure (84.25%).
Arbuscular Mycorrhizal Research: Associations of arbuscular mycorrhizal fungi (AMF) in the rhizospheres of seven rice varieties widely grown in Assam were assessed. The results exhibited the occurrence of AMF spores in the rhizosphere of wet land rice varieties in between 209.00 and 397.00 100/g soil of which highest value observed in Joha rhizosphere (397.00 100/g).
Liquid Formulation: The liquid biofertilizers formulated with 1.0% additive (PVP), 0.1% adjuvant and 0.025% surfactant extended and stabilized the shelf life of Rhizobium (10.11Log cfu/mL), Azospirillum (9.56 Log cfu/mL), phosphate solubilizing bacteria (9.76 Log cfu/mL) Potassium solubilizing bacteria(8.23 Log cfu/mL), Zinc solubilizing bacteria (10.56 Log cfu/mL) and Azotobacter (7.23 Log cfu/mL) upto 10 months.
Solid Formulation: Similarly, Rhizobium, Azotobacter, Azospirillum, Phosphate solubilizing bacteria, Potassium solubilizing bacteria and Zinc solubilizing bacteria having shelf life of six months in compost+charcoal as carrier materials were developed in solid formulation.
Consortia Group: (a)Three different consortia were developed using three nitrogen (N) fixing bacteria consisting of symbiotic N-fixing Rhizobium sp, microaerophilic Azospirillum brasilense and aerobic Azotobacter chrococcum. Bacillus subtilis a phosphate solubilizing bacterium (PSB), Burkholderia ambifaria a zinc solubilizing bacteria (ZSB) and Serratia liquifaciens a potash solubilizing bacteria (KSB) were also used while preparation of consortia. All the PGPR utilized for preparation of consortia had undergone prior screening and molecular characterization. The prospective PGPR isolates were then cryo-preserved under the All India Network Project on Soil Biodiversity-Biofertilizers, Department of Soil Science, AAU, Jorhat.(b)The rationale behind the selection of N-fixing bacteria was that, Rhizobium plays role of symbiotic N-fixer, Azospirillum acts as microaerophillic N-fixer and Azotobacter functions as aerobic N-fixer. All of these N fixers have different mode of action in different soil types and used as per crop requirement. As such three different consortia viz: (i) Rhizobium with PSB+KSB, (ii) Azospirillum with PSB+KSB and (iii) Azotobacter with PSB+KSB were formulated. Prior to development of consortia, the individual cultures were enumerated in specific media at one month interval to understand the status of viable counts for three consecutive months. Zinc solubilizing bacteria in consortia mode is prepared as customised, particularly for Zn deficient (< 0.6ppm DTPA-Zn)sites.
Enriched compost: Normal farm compost around 30:1 C:N ratio could be converted into a superior bio-enriched compost by amending with 1%P as rock phosphate (RP) together with inoculating N-Fixers (108-109 cfu /g or mL) , Phosphate Solubilizing Bacteria (PSB) (108-109 cfu / g or mL) and Potassium solubilizing bacteria(108-109 cfu / g or mL), each and subsequently curing for about 20 to 25 days in shade at 25% moisture level. To maintain the moisture during curing materials should be covered with a polythene sheet / gunny bags.Quality improvement of the final product results because of the change of following characteristics over normal farm compost:-
(1)Stabilization of C:N ratio around 10.0 to12:1
(2) PH stabilizes around neutral (7 to7.5).
(3)CEC of final product increases above 25%.
(4)MBC increases more than 100 times.
(5)Viable population of N-fixer, KSB and PSB 20-30 increase times.
(6)The NPK content of the Enriched Compost [ N%-1.85-1.97, P%-1.03-1.15% and K%-0.81-0.91%]
Development of organic nutrient package for rice: The pooled analysis among the organic inputs (compost, enriched compost, Azolla dual culture and biofertilizers) showed that the application of Azolla (0.5t/ha) with biofertilizer exhibited highest grain yield (3.41t/ha) which was at par with the application of enriched compost @ 5 t/ ha (3.37t/ ha) or compost @ 5 t/ ha with biofertilizers (3.34 t/ ha).
Evaluation of biofertilizerse for Hot Chilli: The pooled analysis of data for four years recorded significantly highest fresh yield of hot chilli (2180 kg/ ha) on application of enriched compost @10t/ha (contained Azospirillum and PSB @ 1.0% and rock phosphate @1.0% as P).
Development of biofertilizer package for Fibre Crop (Jute):The pooled analysis of three years result exhibited that the INM treatment consisted of 50% NP (15 and 13 kg/ha) and 100%K (25kg/ha) with biofertilizer consortia (Azospirillum, Azotobacter and PSB) as seed treatment produced highest (2760 kg/ha) fibre yield which was comparable with the 100% chemical fertilizers (2660 kg/ ha).
Performance of Zn solubilizing bacteria for Zn nutrition in rice: The Zn solubilizing isolate (ZSBS1) from rice rhizosphere could increase significantly higher concentration of Zn (33.14 mg/ kg) in rice grain compared to application of ZnSO4 (29.18 mg/kg). Compared to the control, the DTPA-Zn after harvest of rice was significantly higher either in inoculation (1.33-1.41ppm) or application of ZnSO4 (1.75ppm).
Performance of potassium solubilizing bacteria for reduction of MOP in sali rice: Application of microbial consortia of KSB (Bacillus proteolyticus +Bacillus serratia) could substantially reduce potassic fertilizers (by 20kg/ha) and maintained the comparable paddy yield (4.16t/ha) with inorganic fertilizers (4.28 t/ha) through N:P: K@ 60:20:40 kg/ha).
Long term INM in rice: In long term integrated nutrient management for ten years, the application of enriched compost (2t/ha) amid reduction of 75% nitrogenous and phosphatic fertilizers improved the soil quality index (1.00) and sustainable yield index (0.88) with rice production of 4.12 t/ha.
Enriched compost as component of INM in potato grown by TPS tuberlet: By supplementation of 50 % (60 kg/ha) of recommended N (120.0 kg/ ha) through enriched compost (EC) and vermicompost (VC) for two years, significantly highest tuber yield (26.63t/ha) was recorded compared to the application of 100% N (19.46t/ha).
Microbial consortium and organic inputs on the performance of cauliflower and knolkhol: Microbial consortium (Azotobacter, Azospirillum and PSB) and enriched compost (@5.0t/ha) could resulted the curd yield of 20.90t/ha.In case of knolkhol,microbial consortium (Azotobacter, Azospirillum and PSB) and enriched compost (@5.0t/ha) could resulted the knob yield of 169.73t/ha.
Growth and cutflower production of Gerbera (Cv. Red Gem) through organic inputs: Three years experiments on the use of biofertilizer and organic sources on the cut flower production of Gerbera illustrated the performance of enriched compost @10t/ha in increasing the number of flower (38.19/plant), size of flower (9.53cm), self-life (21.12days) and vase life(10 days).
Cultivation of cabbage using organic sources of nutrients: The application of Biofertilizer (Azotobacter+PSB) @3.5kg each as seedling root dip treatment and RP(as per rate of SSP 60kg/ha)mixingwith vermicompost (5t/ha) recorded the highest yield of 17.94t/ha.
Cultivation of carrot through organic sources of nutrients: The application of enriched compost (5t/ha) with biofertilizer (AzotobacterandPSB) @400gm each as seed treatment and rock phosphate(as per rate of SSP 60kg/ha) recorded highest yield of 21.44 t/ha.
Organic rice cultivation: Several options of organic nutrients are available depending on the availability at different locations. i) Enriched Compost (@ 5 t/ha) + Biofertilizer (Azospirillum, PSB and KSB mix @ 4.0 kg/ha as seedling root dip). ii) Fresh Azolla @ 400-450 kg/ha as dual crop + Biofertilizers (Azospirillum, PSB and KSB mix @ 4.0 kg/ha as seedling root dip).
Organic cultivation of hot chilli: Enriched compost @10t/ha (contained 1% each of Azospirillum and PSB with rock phosphate @1.0% as P) or enriched compost @5.0t/ha+biofertilizers consortia [(Azospirillum+PSB+KSB) (as seedling root dip @ 500mL for seedlings of 1.ha area] recommended as organic nutrient for hot chilli cultivation in NE region. Apply Azotobacter 5g, PSB 5g and Biofor pf 100g per pit within 7 days of transplanting
Integrated nutrient management for Jute: The treatment consisted of 50% N and P (15 and 13 kg/ ha) and 100%K (25kg/ ha) with biofertilizer consortia (Azospirillum and PSB @ 300g each for 10kg seed) as seed treatment recommended as INM for cultivation of Jute.
Zinc solubilizing biofertilizer: Based on the performance, the Zinc solubilizing bacteria(ZSB) @ 3.5kg/ha as seedling root dip treatment, is recommended for Zn nutrition in rice with recommended dose of chemical fertilizers in Zn deficient soils.
Potassium solubilizing bacteria: Recommended potash solubilizing bacteria (Bacillus proteolyticus+ Serratia liquifaciens) @3.5kg as seedling root dip treatment with NPK@60:20:20(kg/ha) for transplanted sali rice. Application of KSB can reduce the potassic fertilizer by 20kg/ha.
Integrated nutrient management in rice: Option I: Half (50%) recommended dose of nitrogenous and phosphatic fertilizers along with full dose (100%) potassic fertilizer and biofertilizers [(Azospirillum + phosphate solubilizing bacteria (PSB)] @3.5kg/ha each (as seedling root dip method). Option II: Half (50%) recommended dose of nitrogenous and phosphatic fertilizers along with full dose (100%) potassic fertilizer and enriched compost @1.0t/ha [In PoP, APART,2019].
Rice based cropping system for organic production in Assam: The biofertilizers (Azospirillum, Azotobacter, Rhizobium, PSB, KSB developed under the project uses for the development of organic nutrient package of (a)Winter rice-potato-lady’s finger sequence and (b)Winter rice-toria-black gram sequence.
Organic package for rapeseed: Seed inoculation: The seed should be moistened with clean water with care so as to avoid excessive wetting. Azotobacter and Phosphate solubilizing bacteria (PSB) should be mixed with @ 50 g each /kg seed.
Organic sesame, Blackgram, Greengram and Lentil: Biofertilizers (Rhizobium and PSB) were utilized for organic package.
Organic cauliflower: Seedlings roots are dipped in a slurry of Azotobacter (AZB) and Phosphorus Solubilizing Bacteria (PSB) mixture for 30 minutes (Slurry is prepared by mixing 75 g AZB and 75 g PSB for 1000 Nos. of seedlings. Manure: Before planting of seedlings in the main field, microbial consortium (Azotobacter, PSB and KSB) is mixed with 2.5 t compost at a ratio of 1 : 100 (1.0% consortia in 100kg compost) for preparation of enriched compost.
Organic carrot : Application of manure and biofertilizers: Rock phosphate @ 30 kg/ha and Enriched compost @ 5 t/ha should be applied before sowing of seed. If enriched compost is not available well decomposed FYM @ 10t/ha also can be used. Seed treatment: Prior to sowing the seed should be well rubbed to remove the fine hairs. The seeds should be treated with a mixture of Azotobacter (AZB) and PSB @ 7.5 g each with 100 g seeds.
Organic turmeric: Treatment of rhizome with microbial consortia (Azospirillum + PSB + KSB) as slurry @ 40 g consortia/ kg at planting for Turmeric along with application of FYM 10 t/ha at the time of final land preparation. As such for one hectare area 500 kg of cowdung and 20 kg microbial consortia will be required.
Organic cabbage: Seedlings are to be transplanted to the main field after 25-30 days of sowing. Before transplanting seedling, roots are dipped in a slurry of Azotobacter (AZB) and Phosphorus Solubilizing Bacteria (PSB) mixture for 30 minutes (Slurry is prepared by mixing 75 g AZB and 75 g PSB for 1000 Nos. of seedlings.
Organic Okra: Seed treatment: Pre-soaking of seeds in water for 24 hrs enhances germination. Floater seeds should be removed and seeds are treated with a mixture of Azotobacter and PSB @ 7.5 g each with 100 g of seeds.
First CAFT: ICAR sponsored 21 days CAFT training on “Culturing Techniques for Biofertilizers and Biopesticides” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 7-27 November, 2017. Course Director: Dr.R.M.Karmakar, HoD, Department of Soil Science; Course Coordinator: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR, Department of Soil Science
Second CAFT: ICAR sponsored 21 days CAFT training on “ Recent Developments in Organic Production Systems” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 7-27 February, 2018. Course Director: Dr.R.M.Karmakar, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR Department of Soil Science.
Third CAFT: ICAR sponsored 21 days CAFT training on “Techniques in Biofertilizers and Biopesticides Production for Organic Agriculture” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 14th November- 4th December, 2018. Course Director: Dr.R.M.Karmakar, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Dr. R. Baruah, Professor, Department of Soil Science.
Fourth CAFT: ICAR sponsored 21 days CAFT training on “Developments in Organic Agriculture” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 6th February- 26th February, 2018. Course Director: Dr.R.M.Karmakar, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Dr. R. Baruah, Professor, Department of Soil Science.
Fifth CAFT: ICAR sponsored 21 days CAFT training on “ Exploitation of Beneficial Microbes in Organic Agriculture” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 4th September- 24th September, 2019. Course Director: Dr.R.M.Karmakar, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Dr. R. Baruah, Professor, Department of Soil Science.
Sixth CAFT: ICAR sponsored 21 days CAFT training on “Organic Agriculture and Soil Health” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 20th February- 11th March, 2020. Course Director: Dr. D. Bhattacharyya, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Dr. R. Baruah, Professor, Department of Soil Science.
Seventh CAFT: ICAR sponsored 10 days CAFT training on “Natural Farming: Way Forward for Sustainable Farming and Ecological Balance” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 13-22, December 2022. Course Director: Dr. D.K.Patgiri, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Dr. Anjuma Gayan, Assistant Professor, Department of Soil Science.
Eight CAFT: ICAR sponsored 10 days CAFT training on “Problems and prospects of natural farming for sustainable ecological balance” was organized by Centre of Advanced Faculty Training (CAFT) in Organic Farming, Department of Soil Science, Faculty of Agriculture, Assam Agricultural University, Jorhat during 13-22, December 2023. Course Director: Dr. D.K.Patgiri, HoD, Department of Soil Science; Course Coordinators: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Dr. Anjuma Gayan, Assistant Professor, Department of Soil Science.
First AAU-ODL: A six month certificate course on the topic “Production of Biofertilizers and Entrepreneurship Development” was conducted by the Department of Soil Science, under AAU-ODL programme, w.e.f March-September, 2023. Course Director: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Course Coordinator: Dr. Anjuma Gayan, Assistant Professor, Department of Soil Science.
Second AAU-ODL: A six month certificate course on the topic “Production of Biofertilizers and Entrepreneurship Development” was conducted by the Department of Soil Science, under AAU-ODL programme, w.e.f May-November, 2024. Course Director: Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR and Course Coordinator: Dr. Anjuma Gayan, Assistant Professor, Department of Soil Science.
Third AAU-ODL: A 15 days AAU-ODL-HRD Programme on “Organic agriculture in NEH Region: A viable commercial venture” was conducted for the Subject Matter Specialists under ATARI Zone VII, 9-22nd November, 2024. Course Director: Dr. Nilay Borah and Course Coordinator, Dr. Dhruba Jyoti Nath, Pr. Scientist, DoR.
Supply of biofertilizers for all India trial: Rhizobium based consortia containing PSB+KSA and ZSB were supplied for all India trial under AICRP on kharif pulses during 2023.
OFT of Integrated Nutrient Management (INM) in rice-toria sequence: Result indicated the average yield of 3.26t/ha in INM [50% NP+RDK+biofertilizers+ compost @1t/ha [RD of NPK for rice is 40:20:20 and for toria 40:35:15(kg/ha)] against the farmers practice of 2.80 with corresponding B:C ratio of 1.56 and 1.38. In toria the INM produces 7.35qt/ha against meagre 5.0qt/ha in farmers practice with B: C ratio of 1.48 and 1.31 respectively.
OFT of nutrient package in organic rice at different KVKs:The treatment consisted of enriched compost (5.0 t/ha) and/or Azolla (0.5 t/ha) with biofertilizers exhibited an average yield of organic rice to the tune of 3.53-4.75t/ha under different KVKs.
OFT of hot chilli under organic inputs: The on farm trials (OFT) with application of EC(10t/ ha) at three sites showed an average fresh yield of hot chilli of 2110 kg/ ha.
OFT of INM in jute:The INM treatment consisted of NPK @ 15:13:25(kg/ha) + Biofertilizer (Azospirillum + PSB, 3.5kg each) as seed coating in Jute in the Jute growing region of Assam illustrated the average fibre yield 2.64 t/ha compared to 2.14t/ha in farmers practice.
OFT of Zn solubilizing bacteria on Zn nutrition in rice:The OFT with the treatment consisted of Zn solubilizing bacteria (@3.5kg/ha, as seedling root dip) + NPK@40:20:20kg/ha exhibited the comparable performances of ZSB with that of inorganic Zn sources (ZnSO4 @ 25kg/ha). The average rice yield (4.24t/ha), Zn concentration in grain(31.13 mg/kg) and the Zn status in the rhizosphere (0.81ppm) after harvest of rice illustrated the importance of ZSB instead of ZnSO4 in Zn deficient (<0.6ppm) soils.
OFT of potassium solubilizing bacteria on in reduction of potassic fertilizers on sali paddy: The treatment consisted of NPK @ 60: 20: 20 (kg/ha)+ Microbial Consortia of KSB (3.5kg/ha) was tested in two KVKs viz: Udalguri and Sibsagar of Assam during 2021-22 (Fig 2). The results showed the range of an average yield between 4.70t/ha and 4.82t/ha at different locations compared to farmers practice (4.40- 4.65t/ha) on application of recommended NPK@ 60:20:40 kg/ha, which was considered as farmers practice in the soil of 131-137kg of available K.
On farm trial results of zinc solubilizing bacteria in reduction of ZnSO4.7H2O in Lentil:The zinc solubilizing bacteria in lentil were tested (2021-22) in five KVK to reduce the ZnSO4.7H2O. Two treatments consisting of T1: Inoculation of seeds with ZSB @ 50 g/kg and basal application of 15 kg ZnSO4/ha and T2: Basal application of 20 kg ZnSO4/ha. Inoculation of seeds with Rhizobium-PSB consortia @ 50 g/kg and basal dose of 10 kg N, 26 kg P2O5, 15 kg K2O/ha are common to both the treatments. The results showed that the seed inoculation of ZSB @50g/kg, could increase the lentil yield by 7.3% while reduced the ZnSO4.7H2O by 5 kg/ ha.
