Biofertilizers organic farming

biofertilizers and their uses

1. BIOFERTILIZERS Presented by, M.Uma Maheshwari , M.Phil Botany

2. ORGANIC FARMING Organic agriculture excludes the use of synthetic compounds It mainly rely on usage of organic substances Organic farming is thus considered as the movement directed towards the philosophy of “Back to nature” It emerged as a priority area for growing demand, long term sustainability and concerns on environmental pollution.

3. Bio fertilizers Bio fertilizers or microbial inoculants are carrier based ready to use live bacterial or fungal formulations, which on application to plants, soil or composting pits, help in mobilization of various nutrients by their biological activity. They are the best modern tool for agriculture. Bio fertilizers contain living micro organisms which promote adequate supply of nutrients

4. Essential component of organic faming Preparation consists of efficient strains of Nitrogen fixing, phosphate solubilizing or cellulolytic micro organisms used for application to seed, soil or composting areas Play a significant role in improving soil fertility by fixing atmospheric nitrogen, with or without plant roots. Solubilizes insoluble phosphates and promote plant growth.

5. Need for bio fertilizers Use of chemical fertilizers leads to the pollution and contamination of soil Demand is much higher than the availability Energy crisis and increasing cost of fertilizers Bio fertilizers are economical, eco-friendly, more efficient, productive and accessible to marginal and small farmers

6. Characteristic features of some bio fertilizers Nitrogen fixers Rhizobium Azospirillum Azotobacter Blue Green Algae (BGA) Phosphate solubilizers Phosphate absorbers Zinc solubilizers

7. Rhizobium Rhizobium belongs to the family Rhizobiaceae Useful for pulse legumes Fix nitrogen 50-100 kg/ha in association with legumes only Nodulation depends on availability of compatible strain for a particular legume.

8. Rhizobium Rhizobium has the ability to fix nitrogen in symbiotic association with legumes and non-legume like Parasponia It coloniizes the root and produces the nodules, which acts as a factories of ammonia production Artificial seed inoculation is needed to restore the population of effective strains of Rhizobium near the rhizosphere to hasten N-fixation Each legume requires a specific species of Rhizobium to form effective nodules

9. Azospirillum It belongs to Spirilinaceae , heterophytic and associative in nature Fix nitrogen about 20 – 40 kg/ha Many species A. amazonense A. halopraeferens A. brasilense But A. lipoferum , A. brasilense are worldwide distribution

10. It has symbiotic association with plants having C4-dicarboxylic acid cycle They grow and fix nitrogen on salts of organic acids Mainly recommended for maize, sugarcane, pearl millet, Sorghum , etc., They colonize the roots not only on root surface but also penetrates into the root tissues They do not produce any visible nodules

11. Azotobacter Belongs to the family Azotobacetriaceae , aerobic, living and heterotrophic in nature Many species A. vinelandii , A. baijerinckii , A. insignis and A. macrocytogenes . A. chroococcum is the most commonly occurring spp. The number of Azotobacter exceeds 105/g soil due to lack of organic matter and presence of antagonistic organisms

12. The bacterium produces anti-fungal antibiotics- inhibits pathogenic fungus Preventing seedling mortality The population is very low in rhizosphere and uncultivated lands Mainly reported in crop plants like rice, maize, sugarcane, bajra , vegetables and plantation crops

13. Blue Green Algae Belongs to eight different families Phototrophic in nature and produces auxin , gibberllic acid and Indole Acetic Acid Fix 20-30 kg/ha nitrogen Abundant in paddy fields so called ‘paddy organisms’ Forms symbotic association with fungi, liverworts, ferns and flowering plants

14. The most common association had been found between floating aquatic fern Azolla , Anabaena azollae (BGA). Important character is that it decomposes quickly The most common species found in India is Azolla pinnata The fern forms a green mat with a branched stem, deeply bilobed leaves and roots India has recently introduced some species of Azolla for their large biomass production A. caroliniana A. microphylla A. filiculoides A. mexicana

15. Phosphate solubilzers Several reports have reported that bacterial spp. Can solubilize insoluble inorganic phosphates Genera like Bacillus, Burkholderia , Achromobacter , Agrobacterium , Microccous , Aerobacter , Flavobacterium and Erwinia Only considerable populations are seen on the rhizosphere The soil bacteria belonging to Bacillus and Pseudomonas are common

16. Phosphate absorbers Mycorrhiza – fungus root Symbiotic association between host plants and certain group of fungi The fungal partner is benefited by obtaining carbon requirements Host is benefited by getting nutrients They are mainly associated with agricultural crops excepts members of Polygalaceae , Cyperaceae , Amaranthaceae , Caryophyllaceae , Chenopodiaceae , Juncaceae and Brassicaceae

17. Zinc solubilizers Nitrogen fixers like Rhizobium , Azospirillum , Azotobacter , BGA and phosphate solubilizing bateria like Bacillus magaterium , Pseudomonas striata and phosphate mobilizing Mycorrhiza can only supply major nutrients to host plants. Zinc can be solubilized by Bacillus subtilis , Thiobacillus thioxidans and Saccharomyces spp. Bacillus subtilis can be used as a biofertilizer in soil where native zinc is in higher concentration

18. Uses of biofertilizers Renewable source of nutrients Sustain soil health Supplement chemical fertilizers. Replace 25-30% chemical fertilizers Increase the grain yields by 10-40%. Decompose plant residues, and stabilize C:N ratio of soil Improve texture, structure and water holding capacity of soil No adverse effect on plant growth and soil fertility. Stimulates plant growth by secreting growth hormones. Secrete fungistatic and antibiotic like substances Solubilize and mobilize nutrients Eco-friendly, non-pollutants and cost effective method

19. Conclusion Biofertilizers are essential components in maintaining long term fertility and sustainablity by fixing atmospheric nitrogen, mobilizing fixed macro and micro nutrients thereby increasing their efficiency and availability Organic manures would be a viable option for farmers to increase productivity per unit area. Therefore reducing pollution and increasing sustainability.

20. Thank you