biochar. It is also believed that adding biochar to composts and manures can reduce odors. Another organic fertilizer made by Japan as bokashi, that is a fertilizer combining “effective” microbes, molasses, biochar, bran, and animal manure with water, and incubating under anaerobic or partially anaerobic conditions. Rice hull biochar is often used due to the availability of rice hulls in many regions. However, great care must be exercised while carbonizing rice hulls, as high process temperatures can lead to the production of carcinogenic compounds. Potential Health Issues of Biochar Application Health risks from biochar relate to possible soil and thus food contamination, and to the effects of breathing in small biochar particles. Contamination can come either from contaminated biomass or from the pyrolysis process. For example, trees absorb heavy metals and other air pollutants and when wood is burnt or pyrolysed, those become concentrated in the ash, which forms part of the biochar. The ash retained after burning wood from forests well away from any sources of pollution contained so many heavy metals that some of it should have qualified as toxic waste. Depending on the pyrolysis temperature and the original biomass, there is a risk of particles called Polycyclic Aromatic Hydrocarbons (PAHs) forming, some of which are known to cause cancer and birth defects. All of this can be avoided by testing different batches of biochar before they are used. Breathing in small charcoal particles can cause ‘black lung disease’ or pneumoconiosis. Furthermore, breathing in ash residues from charred rice husks is linked to a risk of the lung disease silicosis. Both are potentially fatal lung diseases. These risks can be significantly reduced if people who handle and apply biochar wear adequate masks. Conclusion Biochar has a both positive as well as negative impact on crop growth, yield and human health. This technology involves a large biomass demand for production as well as fine biochar particles are causing severe health hazards thus, it is critical that we address this issue with caution. However, application of biochar to damaged soils of low fertility seems promising and has a high potential for mitigating climate change and helping to raise soil fertility but not a silver bullet to improve nutrient economy in farming, or to increase crop yields. We need to investigate and utilise Popular Kheti ISSN: 2321-0001 47 Joshi et al., 2013, Pop. Kheti, 1(1):41-48
it to reduce our emissions and sustain soils, but we cannot rely on it for solving our emerging problems. References Cheng CH, Lehmann J, Thies JE and Burton SD. 2008. Stability of black carbon in soils across a climatic gradient. Journal of Geophysical Research-Biogeosciences,113,G02027. (Available online at http://www.css.cornell.edu/faculty/lehmann/publ/JGeophysRes%20113,%20G02027,%202008%20Cheng.pdf ) Liang B, Lehmann J, Solomon D, Sohi S, Thies JE, Skjemstad JO, Luizao FJ, Engelhard MH, Neves EG and Wirick S. 2008. Stability of biomass derived black carbon in soils. Geochimica et Cosmochimica Acta72:6096–6078. (Available online at http://www.css.cornell.edu/faculty/lehmann/publ/GeochimCosmochimActa%2072,%206096-6078,%202008%20Liang.pdf ) Woolf, D., Amonette, J. E., Street-Perrott, F. A., Lehmann, J. and Joseph. S. 2010. Sustainable biochar to mitigate global climate change. Nature Communications 1, Article number: 56 (Available online at www.nature.com/ncomms/journal/v1/n5/full/ncomms1053.html.) Popular Kheti ISSN: 2321-0001 48 Joshi et al., 2013, Pop. Kheti, 1(1):41-48
Earthworms in Agroecosystem: Soil Engineer for Favorable Rhizosphere R. K. Meena , Y. V. Singh , R. S. Bana and Vijay Pooniya 12 1*11Division of Agronomy; Center for Conservation and Utilisation of Blue Green Algae, 2Indian Agricultural Research Institute, New Delhi -110012 *Corresponding author email: [email protected] Long before the invention of agricultural implements, earthworms ploughed the soil, mixing, tilling and building topsoil as they burrowed through the earth. Earthworms are such important biological resources that play a major role in the proper functioning of the soil ecosystem at no cost and so referred as farmer’s friend even though most people pay little attention to this productive and beneficial animal. An agro-ecosystem which is a subset of a conventional ecosystem, earthworms have tremendous potential therein acting as scavenger, helping in recycling of dead and decayed plant material by feeding on them and thus significantly affecting organic matter dynamics in soil and promoting plant growth. An acre of soil may hold up to eight million of earthworms adapted to a wide range of soil and ecosystems habitats throughout the world. Introduction An ecosystem is a natural system that is formed by dynamic interactions between biotic and a-biotic elements in a defined area. Biotic elements include plants, insects (pests, natural enemies, decomposers), microbes and other living organisms, and a-biotic elements comprise weather components such as temperature, relative humidity, wind, sunshine, rain and soil. Each element has its special characteristics and role in the system that, as a function of time and place influences the distribution and population of living organisms. Globally agro-ecosystem covers nearly 40% of terrestrial surface of the earth. An agro-ecosystem can be viewed as a subset of a conventional ecosystem. As the name implies, at the core of an agro-ecosystem, lays the human activity of agriculture. While nature works slowly often over centuries for the production of topsoil, man, through poor agricultural practices, may deplete this valuable resource within an individual's lifetime. In the absence of a rich population of soil animals, 500 to 1000 years may be required to create an inch of topsoil. However, under favourable conditions, earthworms which are considered as lowly creatures to many people can speed up this process to only five years. As agriculture and ultimately civilization, depend on the maintenance of fertile top soil. It is in our best interest to encourage earthworms in Popular Kheti Volume -1, Issue-1 (January-March), 2013 Available online at www.popularkheti.com© 2013 popularkheti.com ISSN:2321-0001 Popular Kheti ISSN:2321-0001 49
their soil building activities. Long before the invention of agricultural implements, earthworms ploughed the soil, mixing, tilling and building topsoil as they burrowed through the earth. Their importance has been clearly recognized for nearly 200 years, and even in the Fourth Century B.C., Aristotle, it is said, aptly referred to earthworms as \"the intestines of the earth\" though he may well have been referring to their appearance rather than to their function. Earthworms (folk names, include dew worm, rain worms, night crawler, angle worm, and Kechua) are important biological resources that have a tremendous potential in agro-ecosystems because they significantly affect soil physical structures and organic matter dynamics and promote plant growth. India is a diverse country harbouring a very high diversity of earthworms, mostly concentrated in Western Ghats and Eastern Himalayas both of which are recognized as biodiversity ‘hot spots’. The Indian earthworm fauna is predominantly composed of native species, which constitute about 89% of total earthworm diversity in the country. Earthworm plays a major role in the proper functioning of the soil ecosystem. It acts as scavenger and helps in recycling of dead and decayed plant material by feeding on them. Earthworm increases the soil fertility and is often referred to as a farmer's friend. It burrows the soil and ingests soil particles coming on its way. Both these processes aerate the soil and help in mixing the soil particles between the upper and underlying layer. The earthworm resembles a cylindrical tube with average length of about 25 cm. Common earthworm can live up to 6 years in captivity. Ecological Groups of Earthworms 1. Litter and surface dwelling species (Epigeic – ‘upon the earth’) 2. Soil dwelling or upper soil surface (Endogeic – ‘within the earth’) 3. Deep burrowing species (Anecic – ‘out of earth’) Comparison of Groups of Earthworms Epigeic Endogeic Anecic Litter feeder Litter dweller Top soil dweller Pigmented No burrows Small size Eg.Eisenia foetidaRich soil feeder No pigmentation Horizontal burrows Extensive Small size Eg.Allolobophora chloroticaLitter + soil feeder Soil dweller Dorsally pigmented vertical burrows large size Eg.Lumbricus terrestrisSource: Eisenhauer, (2010) Fig. 1 Habitat of earthworm’s speciesSource: Eisenhauer, (2010) Meena et al., 2013, Pop. Kheti, 1(1):49-55 Popular Kheti ISSN:2321-0001 50
The Main Biological Mechanisms through Which Earthworms Affect Plant Growth 1.Dispersal and changes in populations and activities of beneficial microorganisms: Large populations of beneficial plant growth promoting (PGP) micro-organisms such as saphrophytic and mycorrhizal fungi, actinomycetes (e.g., Frankia), bacteria and micro-invertebrates such as protozoa and microbivore (fungivorous, bacteriophagous, predatory omnivorous and entomophathogenic) nematodes inhabit the soil. However, they have limited ability to disperse within the soil and have environmental and nutritional limitations in soil for their activities. Invertebrate activities, such as earthworm burrowing and casting, promote soil mixing and bring micro-organisms into contact with inaccessible soil resources, stimulating both their populations and their activity. The earthworm gut also provides an ideal environment for enhanced activity levels or multiplication of some micro-organisms others may be digested or their activity levels reduced by passage through the earthworm gut. The complex resulting effects of earthworms on microbial communities in soils (activity, populations, diversity) depend on the reactions of micro-organisms to passage through the earthworm gut and directly, by feeding and digestive processes or indirectly by burrowing and casting activities, which change root growth and development and the soil environment both superficially (on the earthworm body) or via ingestion-egestion (in casts). The ability of earthworms to disperse micro-organisms or stimulate microbial activity and increase microbial populations depends greatly on the earthworms spatial range of activity, food sources and requirements, litter feeding and behaviour (Brown et al., 2004). 2.Changes in populations and impacts of plant pests, parasites and pathogens: As with beneficial micro-organisms, earthworm feeding, burrowing, casting, and dispersing activities can alter the distribution of populations of plant pathogens such as viruses, bacteria, fungi, parasitic nematodes, or insect pests in soils. Furthermore, by making plants more or less susceptible to these pests, parasites, and pathogens, earthworms can affect root health. These relationships in plant root growth and development are shown as a function of the interactions between a favourable environment for Popular Kheti ISSN:2321-0001 51 Meena et al., 2013, Pop. Kheti, 1(1):49-55
both roots and pathogens and the presence or activity of virulent of infective plant pathogens. The result of these interactions (i.e., plant health status) may therefore be influenced directly or indirectly by earthworm activities. Earthworms are known to transport and consume a wide variety of plant pathogenic fungi and bacteria and plant-parasitic nematodes. If populations of these organisms are reduced either directly by transit through the earthworm gut or indirectly via changes in the soil environment, then the indirect consequences to plant growth may be important, particularly when disease or nematode pressure is reducing crop yields. 3.Earthworms and plant growth-regulating and growth-influencing substances: Earthworms might produce plant growth regulators (PGRs). This was supported by the first report of the presence of PGR substances in the tissues of Aporrectodea caliginosa, Lumbricus rubellus, and Eisenia fetida by Nielson (1965), who extracted indole substances from earthworms and reported increase in the growth of peas because of them. PGR substances he obtained were from micro-organisms living in the earthworm guts and tissues. 4.Root abrasion and ingestion of living plant parts by earthworm: Abrasion may affect plant roots negatively, particularly the small, fine roots or the root tips, which have not yet produced a protective cortex and are more susceptible to physical disturbance. This abrasion may also break up the mycorrhizal hyphal network decreasing root colonization and the many potential benefits of these fungi to plants. 5. Interactions of earthworms with seeds: From the moment a seed germinates, it comes into contact with the soil, a physicochemical environment and a wide range of soil organisms, all of which may have variable degrees of influence on its growth and success as a plant. Moreover, even before a seed germinates, some of these factors may already be influencing its fate. For example, some earthworm species (e.g., Lumbricus terrestris) appear to show a preference for ingesting the seeds of certain plant species, depending on their size, shape, texture, and taste. Moreover, seed germination may be slower or more rapid in egested earthworm castings than in surrounding soils (Piearce et al., 1994).Popular Kheti ISSN:2321-0001 52 Meena et al., 2013, Pop. Kheti, 1(1):49-55
Physical Mechanisms through Which Earthworms Affect Plant Growth The activities of earthworms in the physical engineering of soils can modify (mostly by casting) a wide range of processes, thereby affecting soil physical functions important for root growth and penetration. Casting affects mainly the meso and micro porosity which is important for infiltration and water holding capacity (Brown et al., 2004). Earthworm burrowing creates mostly chemical and biological properties and processes influenced by soil structure. Soil aggregate stability is directly linked with soil erodibility and thus, with soil erosion. Earthworms are known to influence these parameters. Hence earthworms have potential effects of on soil erosion (Fig. 3). Firstly, earthworms are able to modify soil roughness by depositing casts at the soil surface. Secondly, soil aggregate stability which depends on particle size distribution and organic matter content is modified by earthworms. Fig. 2. Diagrammatic representation of ways by which earthworms can affect plant growth via physical changes in the soil environment by burrowing and casting. (Source: Brown et al. (2004))Fig. 3. Potential effects of earthworms on soil erosion. (Source: Blanchart et al. (2004))Popular Kheti ISSN:2321-0001 53 Meena et al., 2013, Pop. Kheti, 1(1):49-55
Chemical Mechanisms through Which Earthworms Affect Plant Growth 1. Changes in nutrient spatiotemporal availability caused by earthworms: The availability of many essential plant nutrients has been shown to increase in structures and burrow walls. This greater nutrient availability is mainly a result of the selective feeding of earthworms on the soil rich in organic matter, clay and nutrients. Such processes include the grinding action of the gizzard, the priming of microbial activity in the gut and the greater populations and activity of micro-organisms in the earthworm casts and burrows that induce chemical changes in earthworm-worked soil. These nutrient enrichment processes differgreatly according to the earthworm species involved, their ecological categories and the feedinghabits, particularly the amounts of plant litter they ingest. The type and placement of the earthwormcasts are also important, affecting the spatiotemporal availability of the nutrients they contain. Surface earthworm casts dry out much more quickly, harden, and if compact arelikely to limit root penetration, thereby reducing the ability of plant roots to obtain the nutrient (Brussaard, 1999). Belowground earthworm casts remain fresh and moist for much longer periods of time and if they are of the decompact types (with more meso and macropores and macro aggregates), allow roots to penetrate more easily and profit from the greater nutrient contents available to plants.2. Earthworm assisted bioremediation of organic contaminants: Application of earthworms (Aporrectodea longa) at a rate of 5 individuals per 2 kg of soils contaminated with non-extractable pesticide (14C-isoproturon, 14C-dicamba and 14C-atrazine) residues for 28 days showed greater release of bound pesticide residue in comparison to the without-earthworm treatments (Gevao et al. 2001). Further when the study was applied to freshly added pesticides, it was noted that the formation of non-extractable residues of 14C-isoproturon, 14C-dicamba and 14C-atrazine were higher by factors of 2, 2 and 4, respectively, in the without-earthworm treatments. Thus, not only did earthworms limit the formation of the bound fraction, they also promoted the release and mineralisation of bound residues (Gevao et al., 2001). Conclusion Earthworms maintain and enhance quality of environment by utilizing and Popular Kheti ISSN:2321-0001 54 Meena et al., 2013, Pop. Kheti, 1(1):49-55
converting agricultural and other wastes into nutrient rich organic compounds which otherwise as such create pollution. Earthworms maintain soil health by improving physical, chemical and biological properties of soil due to which there is a good agro-ecosystem. It helps in effectively harness the beneficial soil micro flora, destroy soil pathogen and convert organic wastes in to vitamins, enzymes, antibiotics, plant growth hormones, protein rich products and others organic compounds. Thus earthworms are extremely useful creatures for better health of agricultural ecosystem. References Brown GG, Edwards CA and Brussaard L. 2004. How earthworms effect plant growth: burrowing into the mechanisms. In: Edwards CA (ed) Earthworm ecology: 13-49.Blanchart E, Albrecht A, Brown G, Decaens T, Duboisset A, Lavelle P, Mariani L and Roose E. 2004. Effects of tropical endogeic earthworms on soil erosion. Agriculture Ecosystems and Environment104: 303-315. Brussaard L. 1999. On the mechanisms of interactions between earthworms and plants, Pedobiologia43: 880-885. Eisenhauer N. 2010. The action of an animal ecosystem engineer: Identification of the main mechanisms of earthworm impacts on soil micro arthropods Pedobiologia53: 343-352.Gevao B, Mordaunt C, Semple KT, Piearce TG and Jones KC. 2001. Bioavailability of nonextractable (bound) pesticide residues to earthworms, Environment Science Technology35: 501–507. Nielson RL. 1965. Presence of plant growth substances in earthworms demonstrated by paper chromatography and the Went pea test, Nature (London)208: 1113-1114. Piearce TG, Roggero N and Tipping R. 1994. Earthworms and seeds. Journal of Biological Education 28:195-202. Popular Kheti ISSN:2321-0001 55 Meena et al., 2013, Pop. Kheti, 1(1):49-55
Biofertilizers and Their Role in Agriculture Rachna Rana , Ramesh and Pooja Kapoor123 1&2 Department of Agronomy, Forages and Grassland Management, Department of Plant Pathology, 3CSK HPKV Palampur-176061, Himachal Pradesh, India Corresponding author email: [email protected] have emerged as a potential environment friendly inputs that are supplemented for proper plant growth. They hold vast potential in meeting plant nutrient requirements while minimizing the use of chemical fertilizers. Biofertilizers are defined as preparations containing living cells or latent cells of efficient strains of microorganisms that help crop plants in uptake of nutrients by their interactions in the rhizosphere. They accelerate certain microbial processes in the soil which augment the extent of availability of nutrients in a form easily assimilated by plants. They help in restoring soil health and thus provide a cost effective way to manage crop yield along with balancing the environment. Biofertilizers Biofertilizer are low cost, renewable sources s of plant nutrients which supplement chemical fertilizers. Biofertilizer is one of the best modern tools for agriculture. Use of Biofertilizer is one of the important components of integrated nutrient management, as they are cost effective and renewable sources of plant nutrients to supplement the chemical fertilizers for sustainable agriculture. The beneficial effect of legumes in improving soil fertility was known since ancient times. The commercial history of Biofertilizers began with the launch of ‘Nitragin’ by Nobbe and Hiltner, a laboratory culture of Rhizobia in 1895, followed by the discovery of Azotobacter and then the blue green algae and a host of other micro-organisms. Azospirillumand Vesicular- Arbuscular Micorrhizae (VAM) are fairly recent discoveries. In India the first study on legume Rhizobium symbiosis was conducted by N. V. Joshi and the first commercial production started as early as 1956. Commonly explored Biofertilizers in India are mentioned below along with some salient features. Different Types of Biofertilizers Rhizobium: Rhizobium belongs to bacterial group and is symbiotic nitrogen fixer. They are the most efficient Biofertilizer as per the quantity of nitrogen fixed concerned. The Popular Kheti Volume -1, Issue-1 (January-March), 2013 Available online at www.popularkheti.com© 2013 popularkheti.com ISSN:2321-0001 Popular Kheti ISSN:2321-0001 56
bacteria infect the legume root and form root nodules within which they reduce molecular nitrogen to ammonia which is utilized by the plant to produce valuable proteins, vitamins and other nitrogen containing compounds. It has been estimated that 40-250 kg N/ha/year is fixed by different legume crops by the microbial activities of Rhizobium (Table 1). Table 1. Quantity of Biological N fixed by Liquid Rhizobium in different crops Host Group Rhizobium Species Crops N fix kg/ha Pea group Rhizobium leguminosarum Green pea, 62- Lentil 132 Soybean group R.japonicum Soybean 57-105 Lupini Group R. lupine orinthopus Lupinus 70- 90 Alfafa grp.Group R.melliloti Melilotus 100- 150 Beans group R. phaseoli Phaseoli 80- 110 Clover group R. trifoli Trifolium 130 Cowpea group R. species Moong, Redgram, 105 Cowpea, Groundnut 57- Cicer group R. species Bengal gram 75- 117 (Source:http://agritech.tnau.ac.in/org_farm/orgfarm_biofertilizertechnology.html) Azotobacter: It is important and well known free living nitrogen fixing aerobic bacterium. It is used as a Bio-Fertilizer for all non leguminous plants especially rice, cotton, vegetables etc. Of the several species of Azotobacter A. chroococcum, happens to be the dominant inhabitant in arable soils capable of fixing N (2-15 mg N fixed/g of carbon) in 22culture media. The lack of organic matter in the soil is a limiting factor for the proliferation of Azotobacter in the soil.Azospirillum :It belongs to bacteria and fix the considerable quantity of nitrogen in the range of 20- 40 kg N/ha in the rhizosphere in non-leguminous plants such as cereals, millets, oilseeds, cotton etc. The organism proliferates under both anaerobic and aerobic conditions. It do not form root nodules and live inside plant roots. It stimulates for the production of growth promoting substance (IAA), disease resistance and drought tolerance. Cyanobacteria: These are free-living as well as symbiotic cyanobacteria (blue green algae) and described by a group of one-celled to many-celled aquatic organisms. These can be brown, purple or red in colour, found in wet and marshy conditions, only used for rice cultivation and do not survive in acidic conditions. Azolla: Azolla is a free-floating water fern that floats in water and fixes atmospheric nitrogen in association with nitrogen fixing blue green alga Anabaena azollae Azolla. is used as biofertilizer for wetland rice and it is known to contribute 40-60 kg N/ha per rice crop. Popular Kheti ISSN:2321-0001 57 Rana et al., 2013, Pop. Kheti, 1(1):56-61
Besides its cultivation as a green manure, Azolla has been used as a sustainable feed substitute for livestock especially dairy cattle, poultry, piggery and fish. Phosphate solubilizing microorganisms (PSM): The species of Pseudomonas, Bacillus, Aspergillus etc. secrete organic acids and lower the pH in their vicinity to bring about dissolution of bound phosphates in soil. AM fungi: An arbuscular mycorrhiza (AM fungi) is a type of mycorrhiza in which the fungus penetrates the cortical cells of the roots of a vascular plant.Silicate solubilizing bacteria (SSB):During the metabolism of microbes several organic acids are produced and these have a dual role in silicate weathering. They supply H ions to +the medium and promote hydrolysis and the organic acids like citric, oxalic acid, Keto acids and hydroxy carboxylic acids which from complexes with cations, promote their removal and retention in the medium in a dissolved state.Plant Growth Promoting Rhizobacteria (PGPR): This group of bacteria colonize roots or rhizosphere soil. These PGPR are referred to as biostimulants and the phytohormones as they produce indole-acetic acid, cytokinins, gibberellins and inhibitors of ethylene production. Liquid Biofertilizers: Biofertilizers such as Rhizobium, Azospirillum and Phosphobacteria are be effectively utilized for rice, pulses, millets, cotton, sugarcane, vegetable and other horticulture crops as liquid formulations. As an alternative, liquid formulation technology has been developed in the Department of Agricultural Microbiology, TNAU, Coimbatore which has more advantages than the carrier inoculants. The advantages of Liquid bio-fertilizer over conventional carrier based Bio-fertilizers are longer shelf life of 12-24 months, no contamination, no loss of properties due to storage upto 45º c, greater potentials to fight with native population, high populations can be maintained, easy identification by typical fermented smell, quality control protocols are easy and quick, better survival on seeds and soil, easy to use by the farmer, dosages is 10 time less than carrier based powder bio-fertilizers, high export potential and very high enzymatic activity since contamination is nil.Application of BiofertilizersSeed treatment: The seeds are uniformly mixed in the slurry of inoculant and then shade dried for 30 minutes. The shade dried seeds Popular Kheti ISSN:2321-0001 58 Rana et al., 2013, Pop. Kheti, 1(1):56-61
are to be sown within 24 hours. One packet of the inoculant (200 g) is sufficient to treat 10 kg of seeds.Seedling root dip: This method is used for transplanted crops. Two packets of the inoculant are mixed in 40 litres of water. The root portion of the seedlings is dipped in the mixture for 5 to 10 minutes and then transplanted.Main field application: Four packets of the inoculant are mixed with 20 kgs of dried and powdered farm yard manure and then broadcasted in the main field just before transplanting. Set treatment: This method is recommended generally for treating the sets of sugarcane, cut pieces of potato and the base of banana suckers. Culture suspension is prepared by mixing 1 kg (5 packets) of bio-fertilizer in 40-50 litres of water and cut pieces of planting material are kept immersed in the suspension for 30 minutes. The cut pieces are dried in shade for some time before planting. For set treatment, the ratio of bio-fertilizer to water is approximately 1:50.Potential Role of Biofertilizers in Agriculture Nitrogen-fixers (NF) and Phosphate solubilizers (PSBs): The incorporation of bio-fertilizers (N fixers) plays major role in improving soil fertility, yield attributing characters and thereby final yield. In addition, their application in soil improves soil biota and minimizes the sole use of chemical fertilizers (Subashini et al. , 2007). It is an established fact that the efficiency of phosphatic fertilizers is very low (15-20%) due to its fixation in acidic and alkaline soils and unfortunately both soil types are predominating in India. Therefore, the inoculations with PSB and other useful microbial inoculants in these soils become mandatory to restore and maintain the effective microbial populations for solubilization of chemically fixed phosphorus and availability of other macro and micronutrients to harvest good sustainable yield of various crops. Mycorrhizae: The fungi that are probably most abundant in agricultural soils are arbuscular mycorrhizal (AM) fungi. They account for 5– 50% of the biomass of soil microbes. Potential Role of AM) fungi in Agriculture are as follows: Improved nutrient uptake (macro and micronutrients): The improvement of P nutrition of plants has been the most recognized beneficial effect of mycorrhizas. It is also reported that the AM- fungi also Popular Kheti ISSN:2321-0001 59 Rana et al., 2013, Pop. Kheti, 1(1):56-61
increases the uptake of K and efficiency of micronutrients like Zn, Cu, Fe etc. By secreting the enzymes, organic acids which makes fixed macro and micronutrients mobile and as such are available for the plant. Better water relation and drought tolerance: AM fungi play an important role in the water economy of plants. Their association improves the hydraulic conductivity of the root at lower soil water potentials and this improvement is one of the factors contributing towards better uptake of water by plants. Soil structure (A physical quality):Mycorrhizal fungi contribute to soil structure by growth of external hyphae into the soil to create a skeletal structure that holds soil particles together, creation of conditions by external hyphae that are conducive for the formation of micro-aggregates, enmeshment of micro aggregates to form macro aggregates and directly tapping carbon resources of the plant to the soils. Enhanced phytohormone activity:The activity of phytohormones like cytokinin and indole acetic acid is significantly higher in plants inoculated with AM. Higher hormone production results in better growth and development of the plant. Crop protection (interaction with soil pathogens) : AM-inoculation considerably increases production and activity of phenolic and phytoalexien compounds due to which the defense mechanism of plant becomes stronger there by imparts the resistance to plants. Constraints in Biofertilizer UseProduction level constraints: Unavailability of appropriate and efficient strains, unavailability of suitable carrier, mutation during fermentation. Market level constraints: Lack of awareness of farmers, inadequate and inexperienced staff, lack of quality assurance, seasonal and unassured demand. Resource constraint: Limited resource generation for Biofertilizer production.Field level constraints: Soil and climatic factors, native microbial population, etc. ConclusionApplication of organic manures particularly Biofertilizers is the only option to improve the soil organic carbon for sustainance of soil quality and future agricultural productivity (Ramesh 2008). Biofertilizer have an important role to play in improving nutrient supplies and their crop availability in the years to come. They are of environment friendly Popular Kheti ISSN:2321-0001 60 Rana et al., 2013, Pop. Kheti, 1(1):56-61
non-bulky and low cost agricultural inputs. A biofertilizer is an organic product containing a specific micro-organism in concentrated form which is derived either from the plant roots or from the soil of root zone (Rhizozsphere). Among the biofertilizers Azotobacter, Azospirillum, Acetobacter are the important for nitrogen fixation, Bacillus sp. and Aspergillus sp. are important for phosphate solubilisation and other soil mineral nutrients. References Ramesh P. 2008. Organic farming research in M.P. Organic farming in rainfed agriculture: Central institute for dry land agriculture, Hyderabad, pp-13-17Sabashini HD, Malarvannan S and Kumar P. 2007. Effect of Biofertilizers on yield of rice cultivars in Pondicherry, India. Asian Journal of Agriculture Research 1(3): 146-150 Sheraz S Mahdi, GI Hassan, SA Samoon, HA Rather, Showkat A Dar and B Zehra.2010. Bio-fertilizers in Organic Agriculture. Journal of Phytology 2(10): 42-54 Popular Kheti ISSN:2321-0001 61 Rana et al., 2013, Pop. Kheti, 1(1):56-61
Compatibility of Bio-agents with Chemical Pesticides: An Innovative Approach in Insect-Pest Management Shanker Lal Sirvi , A. L. Jat , H. R. Choudhary , Narendra Jat , V. K. Tiwari and Nahar Singh 1* 112221Institute of Agricultural Sciences, Banaras Hindu University, Varanasi- 221005, Uttar Pradesh, India 2Rajastahan College of Agriculture, Maharana Pratap University of Agriculture & Technology, Udaipur-313001, Rajasthan, India *Corresponding author email: [email protected] article focuses on compatibility of bio-agents with chemical pesticides as a component of the Integrated Pest Management System in Indian agriculture. So far, use of synthetic chemical pesticides had been the widely used approach for reducing the estimated 45% gross crop loss due to pests and diseases, amounting to around Rs. 290 billion per annum. More and more quantities of chemicals are used for agricultural intensification to feed an ever growing population. In fact, the pest induced loss is on the rise despite increasing usage of pesticides. Biopesticides could play a crucial role in IPM strategies although they cover only about 4% of the global pesticide market. Compatibility is the ability to mix different pesticides without physical or chemical interactions which lead to enhance biological efficiency or reduce phytotoxicity. Compatibility of bio-agents with chemical pesticides is very important for effective pest management. Introduction In the majority of cropping systems today, emphasis is still placed on single technology aspects such as the use of pesticides, host plant resistance and bio-control, etc., consideration rarely being given to their interaction. However, an important approach that could be taken in integrated pest management (IPM) programs is the use of biological pesticides together with a rational use of chemical pesticides. In fact, when a range of pests is present, or when only one method is not efficient, there may often be economic and environmental advantages in combining two or more control methods. Such methods need to be compatible with each other, as incompatibility can lead to loss in effectiveness, increased toxicity to humans and other non target organisms, the development of pesticide resistance, major product loss, and crop injury. Some information on the selectivity of most pesticides to natural enemies of pests is already known, but data on the compatibility of chemical and specific biopesticides are often limited and are sometimes conflicting. IPM has been Popular Kheti Volume -1, Issue-1 (January-March), 2013 Available online at www.popularkheti.com© 2013 popularkheti.com ISSN:2321-0001 Popular Kheti ISSN:2321-0001 62
promoted as a combination of techniques without giving due consideration to the compatibility of each component. Biopesticides could play a crucial role in IPM strategies although they cover only about 4 per cent of the global pesticide market. Biopesticides have high compatibility with other pest management techniques such as natural enemies, resistant varieties etc. Integrating biopesticides with pesticides could enhance performance of IPM strategies What is Compatibility of a Pesticide? Compatibility is the ability to mix different pesticides without physical or chemical interactions which lead to enhance biological efficiency or reduce phytotoxicity. Why Compatibility of Bio-insecticides with Pesticides? After the continued use of an array of chemical pesticides over the decades, many of their limitations have been understood. However, nonselective chemical pesticides can eliminate natural enemies of pests and induce other problems such as secondary pest outbreaks and pest resurgence. Intensive use of most pesticides will often lead to pesticide resistance in target pests. Increasing problems with chemical pesticides have stimulated the search for alternative control measures, such as the use of biological pesticides including viruses, bacteria, fungi, protozoans and nematodes. A common advantage of biological pesticides is that they target a narrow range of pests, and therefore minimize unintended adverse effects on beneficial organisms. Moreover some biological pesticides work better in controlled environments such as greenhouses where consistent results are more likely than in exposed field environments. As the target for biological pesticides is quite narrow, there are still many situations for which they are not available. The use of chemical control agents is still probably the most frequently used and wide spread means of achieving effective and reliable pest reduction. Importance of Compatibility Compatibility of bio-agents with chemical pesticides is very important for effective pest management. Enhanced effectiveness can be achieved by joint action of pathogens and chemical pesticides which ultimately reduce the amount of total chemical insecticides used in crop protection. Microbial insecticides in combination with chemicals insecticides not only reduce the use of sole chemical Sirvi et al., 2013, Pop. Kheti, 1(1):62-67 Popular Kheti ISSN:2321-0001 63
insecticides to an extent but also increase the effectiveness of pesticides. Besides, both in combination would be economically viable reducing cost and risk by improving B:C ratio. Compatibility of bio-agents with chemical pesticides is very important to reduce the chances of development of resistances to newer chemical insecticides. Practices to Promote Compatibility of Chemical and Biological Pesticides 1. Use physiologically selective chemical pesticides to support biological pesticides. 2. Evaluate the probable effect of secondary compounds. 3. Reduce dosages of pesticides. 4. Reduce the area of applying chemical pesticide (e.g. treatments in alternate rows). 5. Reduce the contact between chemical and biological pesticides (e.g. applications in strips or inside traps). 6. The application time of pesticides considering the least amount of interference possible if they are not totally compatible. 7. Avoid the periods of greatest susceptibility of organisms composing the biological pesticides. 8. Use and eventually create through biotechnology pesticide-resistant organisms for biological pesticides. Incompatibility Incompatibility is the inability of a pesticide to mix with other pesticides without producing undesirable effects. Effects of Incompatibility Biological and chemical pesticides can be incompatible as chemical compounds can severely reduce the activity of the live organisms used in biological pesticides, induced mortality, low reproduction rates, reduced infection capacity and changes in host searching behavior. Type of Incompatibility Chemical incompatibility: This is mostly affected by temperature, tank pH and length of time that we hold a spray mixture in the tank before use. Physical ncompatibilitiesi usually involve the inert ingredients of a formulation. The mixture may become unstable, forming crystals, flakes or sludge that may clog spray equipment. Mechanism of Synergistic ActionAll the synergists appear to work by preventing the detoxification of the insecticides with which they are applied. Most of the synergists are microsomal inhibitors or reduce the activity of microsomal enzyme as a result the rate of detoxification of the insecticides by this enzyme is reduced. Popular Kheti ISSN:2321-0001 64 Sirvi et al., 2013, Pop. Kheti, 1(1):62-67
Compatibility of Bio-insecticides Biological control or the use of natural enemies such as parasitoids, predator and/or beneficial bacteria, fungi, virus, and nematodes is an alternative strategy to manage agriculture crop pests. However, the sole use of biological control may not always be sufficient to control plant-feeding insect or mite populations in agriculture pest. As a result, research within the last 5 to 10 years has investigated the possibility of using so-called “bio rational” or “reduced risk” insecticides in conjunction with biological control agents (natural enemies) to determine if there is compatibility when both management strategies are implemented together. Those insecticides that are classified as bio rational or reduced risk include insect growth regulators, insecticidal soaps and horticultural oil and microbial organisms including beneficial bacteria and fungi and related compounds. Bacteria: Microbial pesticides based on the soil-borne bacterium Bacillus thuringiensis(Bt) are among the most widely used groups of biopesticides. Formulations based on Bt sub sp. kurstaki and Bt sub sp. aizawai have been found to be effective against several lepidopteran pests either alone or in combination with pesticides, other biopesticides or biocontrol agents on insect pest. Example of Bacillus thuringiensis var. kurstaki B.t.k. () in combination with plant oil viz B.t.k.. 0.2% + Neem oil 5% and B.t.k. 0.2% + Citronella oil 5%. Virus: Entomopathogenic viruses, especially nucleopolyhedrovirus (NPV) and granulovirus (GV) also are known to be effective against various insect pests. Helicoverpa armigeraNPV (HaNPV), Spodoptera litura NPV (SlNPV) and S. exigua NPV (SeNPV) already have been commercialized and are widely used against tomato fruit worm (Helicoverpa armigera), common army worm (Spodoptera litura) and beet army worm (S. exigua), respectively. The higher larval mortality of H. armigera was found in chickpea at 72 hrs and 1 week after spraying of endosulfan 0.035 per cent + HaNPV 250 LE/ha. (Bhatt and Patel, 2002). Example of viral based pesticides combination viz. NPV + Fenvalerate (0.005%), NPV + Monocrotophos (0.035%), NPV + B.t. and HNPV + NSKE (Neem Seed Kernel Extract) 2.5%. Fungi: Entomopathogenic fungi play a vital role in managing the insect pests in humid tropics, Beauveria bassiana and Metarhizium anisopliae constitute about 68 per cent of the Popular Kheti ISSN:2321-0001 65 Sirvi et al., 2013, Pop. Kheti, 1(1):62-67
entomopathogenic fungi based microbial pesticides (Faria and Wraight, 2007). Temperature and humidity are important factors determining the effectiveness of entomopathogenic fungi. Some example of fungi based pesticides combination viz. Deltamethrin + Beauveria bassiana, Dimethoate 0.015% + Beauveria bassiana and Acetameprite 0.004% + Beauveria bassiana.Nematodes entomopathogens: Parasitism by entomogenous nematodes can have various deleterious effects on their host including sterility, reduced fitness and delayed development and in some cases, rapid mortality. The per cent grub mortality was found relatively higher in combination of nematode and fungus than when applied individually against H. consanguinea. A high mortality of grub (96.7 %) was found in treatment of N 2000 IJs (infective juveniles) + F 1X 10 spores whereas 86.7 per cent 9mortality was observed in nematode alone and 20.0 per cent in fungus alone after 11 days of exposure. (Jat and Choudhary, 2006). Some example of nematodes based pesticides combination viz. Chlorpyriphos- methyl + Hetrorhabtis gyeongsan. Conclusion Effectiveness of insect-pests control can be enhanced with combined use of compatible bio-agents with chemical pesticides. Most of bio-agents have indicating their selective use in IPM. Bacterial pathogens are more compatible with pesticides than fungal and viral entomopathogens. These features of microbial agents help us in their exploitation for eco-friendly and less harmful strategies in modern agriculture and also for reducing pesticide load growing on our agro-ecosystem. Future Thrusts 1. More laboratory and field studies on compatibility of microbial agents with newer and emerging pesticides are required in India. 2. Encouragements for production of bioinsecticides and compatible chemicals as combo products, which should be promoted in future. 3.Krishi Vigyan Kendra’s and NGO’s should also be oriented along with Govt. agencies to give more emphasis on demonstration and timely use of bioinsecticides with compatible chemical pesticides for farmer’s awareness and benefits.Popular Kheti ISSN:2321-0001 66 Sirvi et al., 2013, Pop. Kheti, 1(1):62-67
References Bhatt NJ and Patel RK. 2002. Bioefficacy of various insecticides against Helicoverpa armigera on chickpea. Indian Journal of Entomology64(1):27-34. Faria MR and Wraight de MP. 2007. Mycoinsecticides and mycoacaricides: a comprehensive list with worldwide coverage and international classification of formulation types. Biological Control 43: 237-256. Jat BL and Choudhary RK. 2006. Bioefficacy and compatibility of the insect parasitic nematode, Hetrrorhabditis bacteriophoraand the insect pathogenic fungus, Metarrhizium anisopliae Against the White grub, Holotrichia consanguinea. Indian Journalof Plant Protection, 34 (1): 113-115.Popular Kheti ISSN:2321-0001 67 Sirvi et al., 2013, Pop. Kheti, 1(1):62-67
Jatropha as a Crop of Wastelands in RajasthanSubhash Chandra , Kailash Chand Bairwa , Abimanyu Jhajhria and Dasharath Prasad 1*2341Agricultural Economist-Research Associate, International Maize and Wheat Improvement Centre (CIMMYT), New Delhi-110012, India. 2&3Ph.D. Research Scholar, Division of Agricultural Economics, Indian Agricultural Research Institute (IARI), New Delhi-110 012, India. 4Assistant Professor (Agronomy), Agricultural Research Station, Swami Keshwanand Rajasthan Agricultural University, Sriganganagar-335001, Rajasthan, India. *Corresponding author email: [email protected] known as Jangli Arandi in the State of Rajasthan, Jatropha (Jatropha curcas L.) has very promising scope for cultivation on wastelands because of its various benefits like wasteland reclamation and reforestation, soil improvement, income generation from unusable areas and providing opportunities for sustainable and renewable land resources management etc. Rajasthan is the leading state in Jatropha cultivation covering 90% of total area in the country. Rajasthan government is promoting its production on waste lands through various central government schemes.Introduction The plant Jatropha, also known as Ratanjot, Ho-ho-ba, Jojoba, etc. is most commonly known as Jangli Arandi in the State of Rajasthan. Jatropha plant which belongs to family Euphorbiaceae, bearing botanical name as Jatropha curcas L. is a native plant of South America (the Sonora desert of Arizona, California and New Mexico). Jatropha is naturally a dioecious desert plant. Due to its great ability to withstand hot weather with water scarce low fertile soil, it has very promising scope for cultivation on wastelands even in hot deserts. It also has an ability to withstand high salt concentration in soil. The tribal belt of Kumbalgarh (Udaipur) and Banswara are the leading Jatropha growing area because of the most suitable climate for its commercial plantation in these areas. Status of Jatropha Farming in Rajasthan Rajasthan is the leading state in Jatropha cultivation. Jatropha in the country is now being grown in about 4, 97, 881 hectares of area with the production potential around 25 million tonne per year. About 90 per cent of the Jatropha cultivation is in Rajasthan. Rajasthan government is promoting its production on waste lands. Recently Rajasthan government has allotted 110 hectare of wastelands including 70 hectares at Fatehpur area (Sikar) and 40 hectares at Dhand area (Jaipur) for Jatropha plantation. Popular Kheti Volume -1, Issue-1 (January-March), 2013 Available online at www.popularkheti.com© 2013 popularkheti.com ISSN:2321-0001 Popular Kheti ISSN:2321-0001 68
Jatropha plant starts yielding 3 year after rdplanting and yield increases over the year. ‘Society for Rural Initiatives for Promotion of Herbals’ is the major society for promoting Jatropha cultivation. Schemes for Promoting Jatropha Cultivation in Rajasthan Initially Jojoba plantation project was formulated by Rajasthan government (with the help of central government) in 1995 for a period of five years but later it was extended for few years. Jatropha planting in India has various support mechanisms under the National Employment Guarantee Schemes which includes Comprehensive Land Development Program (CLDP); Drought Prone Area Program (DPAP); Watershed Development Fund (WDF), and National Food for Work Programme (NFWP) etc. Jatropha plantation in Udaipur district of Rajasthan (Source:http://www.nri.org/projects/jatropha/) Benefit(s) of Jatropha Farming Most of the state governments in the country promoting Jatropha cultivation because it has great potential to integrate the rural poor into the bio-fuel value chain while rehabilitating waste lands. Jatropha is a promising crop for Rajasthan as it has various benefits like wasteland reclamation and reforestation, soil preparation, income generation from previously unusable areas, reducing increased demand for employment by providing opportunities for livelihood and sustainable & renewable land resources management. Various industries like bio-fuel industry, cosmetic industries, pharmaceutical industries, food industries, lubricants industries, etc could use Jatropha. Scale of Jatropha Cultivation in India A study was conducted by the Global Exchange for Social Investment (GEXSI) during 2008 which is known as “Global Market Study on Jatropha”. In this study it was assumed that India has great cultivation potential and an estimate was drawn which is shown in Table 1. According to the GEXSI results, 60% of the projects on cultivation of Jatropha are partially or totally on waste lands which are not suitable for agricultural production and 92% of the projects include out-grower schemes. Chandra et al., 2013, Pop. Kheti, 1(1):68-70 Popular Kheti ISSN:2321-0001 69
Table: 1. Estimated Area (for 2010 and 2015) under Jatropha Cultivation Year Expert estimate (ha) 2008 (actual area) 497881 2010 1179760 2015 5479765 The government pursues a policy of guaranteed prices for seed. The seeds under the considered projects were sold at higher prices and seeds were sold mostly to research projects or nurseries. Constraints in Jatropha Cultivation Perceived by Farmers Meena and Sharma (2007) identified various constraints faced by the farmers in the Udaipur district of Rajasthan are as follows i.Lack of technical guidance and information ii.Inadequate training facilities for acquiring skills about its cultivation technology iii.Lack of suitable plantation schedule iv.Long gestation period of Jatropha v.Adverse climatic and edaphic factors for the survival of plants vi.Lack of knowledge about scientific cultivation of Jatropha vii.Lack of awareness of economic value of Jatropha seeds According to this study, lack of technical guidance and information, non-availability of improved varieties of Jatropha plants and lack of marketing facility for sale of produce were perceived as major constraints by tribal and non-tribal Jatropha growers. Furthermore, tribal respondents perceived more constraints than non-tribal farmers in cultivation of Jatropha plants. Conclusion Jatropha has multi-dimensional impacts not only on livelihood of farmers but also on environment. On one hand it protects wastelands through reforestation while on the other it provides a source of income to the family. A policy by government which includes introduction of high-yielding varieties, input(s) at subsidized prices, and promotion of Jatropha based industries can lead to the success of Jatropha promoting projects. References Sharma SC and Bangarva GS. 1999. Constraints in tree plantation and their survival perceived by the farmers, forest and extension personnel and local leaders. Rural India, 62:109-113. Meena HR and Sharma FL. 2007. Constraints in Jatropha cultivation perceived by farmers in Udaipur district of Rajasthan. Wastelands News, 22(4):36-37. The Global Exchange for Social Investment (GEXSI) (2008). Global market study on jatropha: Final report prepared for the World Wide Fund for Nature (WWF). Popular Kheti ISSN:2321-0001 70 Chandra et al., 2013, Pop. Kheti, 1(1):68-70
Aconitum ferox Wall. ex Ser.- An Important Medicinal Plant of Sikkim Chandan Singh Purohit Botanical Survey of India, Sikkim Himalayan Regional Centre, Gangtok, Sikkim-737103 Email: [email protected] [email protected]; Introduction About 3000 plants are known in India for their medicinal use and about 6000 plant are used as traditional, folk and herbal medicine. The country has about 2500-3000 species of medicinal plants and our dependence on medicinal plants has in no way minimized by the use of modern systems of synthetic drug whose use are not without side-effects. Phytochemical contents of the genus Aconitum have been bestowed with the number of medicinal compassion which includes antibacterial, antioxidant anti-proliferative, enzyme inhibition activities, etc. Its tuberous roots are 5-8 cm long and conical. They are first sweet in taste and then bitter and with tingling effects. India receives its supply mostly from Nepal (Sheokand et al., 2012; Sarkar et al., 2012).In the tenth century, the Persian physician Alheroo described the plant under the name bish. Europeans first became aware of Aconitum ferox in the nineteenth century during journeys to Nepal. During the nineteenth century, there was a thriving trade in the root tubers of Aconitum ferox, which were brought from Lhasa via Le (Mustang) to Ladakh. Aconitum ferox Wall. ex Ser. Family: Ranunculaceae Synonym: Aconitum atrox Walp.; Aconitum atrox (Bruhl) Mukerjee; Aconitum virosumDon., Aconitum napellus var. rigidum Hook.f. Meaning of Aconitum L. Gr. Akonitonderived from akon, an arrow. In ancient times the juice of the roots of Aconitum was used as an arrow poison. According to Pliny Aconitum ferox is referred to as \"vatsanabha\" in the Shushrutasamhita. It is used in treatment of cough, asthma, leprosy, fever, muscular rheumatism as well as against snake bite, neuralgia, skin disease, acute gout, etc. Because of its over exploited in Himalayan region for medicinal use, it has become present day an endangered plant of Sikkim. Recently its population is very scanty in nature, so its ex-situ and in-situ conservation is necessary. One another plant Aconitum chasmanthum is an alternative source of this plant and it is usually sold under the name \"vatsanabha\". Popular Kheti ISSN:2321-0001 71 Popular Kheti Volume -1, Issue-1 (January-March), 2013 Available online at www.popularkheti.com© 2013 popularkheti.com ISSN:2321-0001
the plant was abundant in Acone, a harbor in Heraclea in Bithynia near Black Sea and hence the generic name, supposed to be derived from it. In Greek mythology the name Aconitum was derived from the Mount Aconitus where Hercules had a fight with Cerberus a mad dog, progeny of Typhon and the serpent woman Echidna. It was believed that this plant originated from the deadly saliva of Cerberus (Nayar, 1985). Vernacular name- Bhutia: Bikh, Bikhma Nepali: Akphale, Bikh, Bish, niloBikh Lepcha: Nyine English: Aconite, Monkdhood, Wolf’s bane, Indian aconite Sanskrit: Vatsanabha, Visa Hindi: Bish, Mahoor Gujarati: Vachang Marathi: Vachang Tamil: Vasnumbi Telugu: Vasnabhi Common name: Indian Aconite, Bishnag Trade name: Bish Ayurvedic: Garala, Vajraanga, Visha, Vatsanaabha, Sthaavaravisha, Vatsanaagaka, Shrangikavisha, Amrita Unani: Bish, Bishnaag Siddha: Vasanaavi, Karunaabhi Folk: Bish, Mithaa Zahar, TeliaVisha, BacchanaagHabit- Perennial plant Frequency- common around 10,000-14000 ft altitude. Habitat range- The plant is a common sight at lower alpine region during July-August. In the Sikkim Himalaya, it is found at the North-eastern Sikkim, Nathula region, Singalela ridges and the Dzongri area. Distribution- Temperate Alpine Himalayas of Sikkim at 10,000 to 14,000 ft altitude in Kishong-La, Thangu at North Sikkim. It is the second most used species and distributed from Nepal to Arunachal Pradesh. Plant Description- Perennial erect herb growing up to 2 m in height; roots look like the navel of children (Plate-1). Root- Caudex carrot-shaped or fusiform, small, 0.7–1.6 cm.Stem- 5.5–38 cm tall, simple or basally branched, basally glabrous, apically sparsely retrorse and appressed pubescent. Leaf- Basal leaves long petiolate; petiole 2–14 cm, glabrous, base without distinctsheath; leaf blade reniform-pentagonal or reniform, 1–2×1.3–3.2 cm, abaxially glabrous, adaxially sparsely pubescent, 3-parted nearly to middle; central lobe rhombic-obtrapezoid; lateral lobes obliquely flabellate, unequally 2-fid nearly to middle. Cauline leaves 1–3, shortly petiolate. Inflorescence 1–5-flowered; rachis and pedicels retrorse Purohit CS, 2013, Pop. Kheti, 1(1): 71-75 Popular Kheti ISSN:2321-0001 72
Plate-1. Different plant parts of Aconitum ferox Wall. ex Ser.Purohit CS, 2013, Pop. Kheti, 1(1): 71-75 Popular Kheti ISSN:2321-0001 73
pubescent; proximal bracts leaf like, others linear. Inflorescence- Proximal pedicels 2.4–6.5 cm, distal ones 1.5-2 cm, with 2 distal bracteoles orbordering flower, bracteoles linear, 5.5–6.5 × 0.6–1.2 mm. Calyx- Sepals violet or purple, abaxially sparsely pubescent; lower sepals 0.8-1 cm; lateral sepals 1.4-1.8 cm; upper sepal navicular, 1.4-1.8 cm from base to beak, lowermargin slightly concave or sub-erect. Corolla- Petals glabrous; claw slender; limb small, 2-3 mm; lip 1-2 mm, slightly concave. Androecium- Stamens sparsely pubescent; filaments sparsely pubescent, entire or 2-denticulate. Gynoecium- Carpels 5, sparsely pubescent. Fruit- Follicles 1–1.4 cm. Seed sub-pyramidal, 1.5-2.5 mm (Grierson & Long, 1984). Phenology- Its budding starts from June last week. First flower open usually in July second week to third weed. September month is most blooming time and after it, flower fall starts and at the end of month of August, all flowers fall and fruits initiate. When the winter time starts (November to December), all fruits reach to maturity. Specimen examined: Sikkim- Kishong La, North Sikkim 18.9.1996, 4000m, SK Jana, col.no-18304 (BHSC-30774). Associated vegetation- Meconopsis paniculata, Podophyllum hexandrum, Pedicularis longiflora and many species of GenusRhodiola, Carex, Eragrostis, Potentilla, Aster, Gnephalium etc. Constituents: The tuber of Vatsanabha contains 0.4–0.8% diterpene alkaloids and the concentrations of aconite in fresh plant are between 0.3% and 2.0% in tubers and 0.2% and 1.2% in the leaves. The highest concentration of aconite is found during winter. The major alkaloids are aconitine, pseudaconitine, bikhaconitine, diacetylpseudaconitine, aconine, picro-aconine, veratrypseudaconitine, chamaconitine, veratrylgamaaconine and di-Ac–Y-aconitine. Parts used- Tuberous root. Medicinal uses- It is medicinally important plant and its major uses are as follow:- ·Root is used as an antidote for lethal poisons of local origin. The root powder is used to relieve severe body pain, diabetes, debility, asthma, ear and nose discharge, leprosy, paralysis, rheumatism, and typhoid. It is also considered to be diaphoretic, diuretic, expectorant, febrifuge, and dyspepsia (Gurung, 2002). It is extremely poisonous and used against snake bite, neuralgia, skin disease, acute gout, etc. Purohit CS, 2013, Pop. Kheti, 1(1): 71-75 Popular Kheti ISSN:2321-0001 74
·Aconitum ferox is also known as smanchen, \"great medicine\"; the crushed roots, mixed with bezoar stones, are used as a universal antidote. The root is also used to treat malignant tumors. In Nepalese folk medicine, blue aconite is used to treat leprosy, cholera, and rheumatism. ·The root is also used as an antidote to hartal, believed to be a lethal poison of local origin. The root finds use in cold, neuralgia and inflammation, fever, indigestion, and stimulation of bile secretion. Conclusion: Aconitum ferox is an important medicinal plant used to cure various diseases like leprosy, paralysis, rheumatism, diabetes, debility etc. Because of it’s over exploitation for medicinal use, its population continues to decline in nature. So it needs to conserve for future use. ReferencesGrierson AJC and Long DG 1984. Flora of Bhutan including a record of plants from Sikkim. 1(2) – 319. Nayar MP 1985. Meaning of Indian flowering plant names, Bishen Singh Mahendra Pal Singh, Dehradun; page-20-21. Sarkar PK, Prajapati PK, Pillai APG and Chauhan MG 2012.Pharmacognosy of aconite sold under the name Vatsanabha in Indian market. Indian J. Trad. Knowledge 11(4) – 685-696. Sheokand A, Sharma A and Gothecha VK 2012.Vatsanabha (Acontiumferox): From Visha to Amrita. Int. J. Ayur. Her. Medicine 2(3) - 423-426. Gurung BJ 2002. The medicinal plants of the Sikkim Himalaya. Mapples- west Sikkim; p-8. Purohit CS, 2013, Pop. Kheti, 1(1): 71-75 Popular Kheti ISSN:2321-0001 75
Salinisation: Causes and Prevention 1Manoj Kumar*, Ekta Joshi and Aanandi Lal Jat 121Indian Agricultural Research Institute, New Delhi-110012 2Department of Agronomy, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi- 221005 *Corresponding author email: [email protected] The term 'salinity' strikes fear into the hearts of many farmers. Some call it the white death because it conjures up images of lifeless, shining deserts studded with dead trees. Fears of the 'white death' seem justified. It threatens agricultural productivity in 77 m ha of agricultural land of which only 45 m ha (20% of irrigated area) is irrigated. Salinity affects the growth, development and productivity of crops worldwide. In India, more than 8.6 m ha of lands are salt affected and poses problem to productivity of crops. Wheat, the second important staple food crop of India, faces salinization problem resulting in decrease in average yield by more than 50%, due to which stable supply of food becomes a question mark in light of increasing global population which is expected to touch 9 billion in 2050. Introduction A worldwide phenomenon of accumulation of excess salts in the root zone results in a partial or complete loss of soil productivity. The problem of soil salinity is widespread in arid and semi-arid regions though salt affected soils are also found extensively in sub-humid and humid climates, particularly in the coastal regions where the ingress of sea water through estuaries & rivers causes large-scale salinization. Soil salinity is also a serious problem in areas where groundwater of high salt content is used for irrigation. The most serious salinity problems are being faced in those arid and semi-arid regions of the world where irrigation is essential to increase agricultural production to satisfy food requirements. Irrigation in these areas requires skilled management. Failure to apply principles of efficient water management may result in wastage of water. Over-watering and inadequate drainage results in waterlogging, loss of cultivable land and salinity problems which reduce the soil productivity. Nearly 50 percent of the irrigated land in the arid and semi-arid regions has some degree of soil salinization problems. This shows the magnitude of the problem that must be tackled in order to meet future global food needs. It is generally agreed that the future food needs of increasing population will be met by Popular Kheti Volume -1, Issue-1 (January-March), 2013 Available online at www.popularkheti.com© 2013 popularkheti.com ISSN:2321-0001 Popular Kheti ISSN:2321-0001 76
directing the efforts of all concerned towards improving the level of management of soils already under cultivation, and by bringing under plough the potentially arable soils which are presently uncultivated. Soil salinity is a major impediment in achieving potential crop yields. Measures to combat desertification, preventing and controlling water logging, salinization and sodication by modifying farming techniques in a regular and sustained way using an integrated approach is need of present day agriculture. The problems of salt-affected soils are old but their magnitude and intensity have been increasing fast due to large-scale efforts to bring additional areas under irrigation in recent decades. The problems have been made worse by development of irrigation systems without adequate provision for drainage and are being aggravated by poor water management practices and unsound reclamation procedures. Origin of Salts The presence of excess salts on the soil surface and in the root zone characterizes all saline soils. The main source of all salts in the soil is the primary minerals in the exposed layer of the earth’s crust. During the process of chemical weathering which involves hydrolysis, hydration, solution, oxidation, carbonation and other processes, the salt constituents are gradually released and made soluble. The released salts are transported away from their source of origin through surface or groundwater streams. The salts in the groundwater stream are gradually concentrated as the water with dissolved salts moves from the more humid to the less humid and relatively arid areas. The predominant ions near the site of weathering in the presence of carbon dioxide will be carbonates and hydrogen-carbonates of calcium, magnesium, potassium and sodium; their concentrations, however, are low. As the water with dissolved solutes moves from the more humid to the arid regions, the salts are concentrated and the concentration may become high enough to result in precipitation of salts of low solubility. Salinity and Plant Growth Excess soil salinity causes poor and spotty stands of crops, uneven and stunted growth (Fig. 1) and poor yields, the extent depending on the degree of salinity. Fig.1. Salt tolerant v/s salt sensitive (Source: http://www.growflow.com.au/soil-salinity-reduction/) Popular Kheti ISSN:2321-0001 77 Kumar et al., 2013, Pop. Kheti, 1(1): 76-79
The primary effect of excess salinity is that it renders less water available to plants although some is still present in the root zone. This is because the osmotic pressure of the soil solution increases as the salt concentration increases. Reclamation and Management of Salt Affected Soils1. Salt leaching 2. Drainage 1. Salt Leaching The amount of crop yield reduction depends on such factors as crop growth, the salt content of the soil, climatic conditions, etc. In extreme cases where the concentration of salts in the root zone is very high, crop growth may be entirely prevented. To improve crop growth in such soils the excess salts must be removed from the root zone. The term reclamation of saline soils refers to the methods used to remove soluble salts from the root zone. Methods commonly adopted or proposed to accomplish this include the following: ·Scraping: Removing the salts that have accumulated on the soil surface by mechanical means has had only a limited success although many farmers have resorted to this procedure. Although this method might temporarily improve crop growth, the ultimate disposal of salts still poses a major problem. ·Flushing: Washing away the surface accumulated salts by flushing water over the surface is sometimes used to desalinize soils having surface salt crusts. Because the amount of salts that can be flushed from a soil is rather small, this method does not have much practical significance. ·Leaching: This is by far the most effective procedure for removing salts from the root zone of soils. Leaching is most often accomplished by ponding fresh water on the soil surface and allowing it to infiltrate. Leaching is effective when the salty drainage water is discharged through subsurface drains that carry the leached salts out of the area under reclamation. 2. DrainageProvision of adequate drainage measures is the only way to control the groundwater table. ·Surface drainage: In surface drainage, ditches are provided so that excess water will run off before it enters the soil. However the water intake rates of soils should be kept as high as possible so that water which could be stored will not be drained off. Field ditches empty into collecting ditches built to follow a natural water course. A natural grade or fall is Popular Kheti ISSN:2321-0001 78 Kumar et al., 2013, Pop. Kheti, 1(1): 76-79
needed to carry the water away from the area to be drained. ·Subsurface drainage: If the natural subsurface drainage is insufficient to carry the excess water and dissolved salts away from an area without the groundwater table rising to a point where root aeration is affected adversely and the groundwater contributes appreciably to soil salinization, it may be necessary to install an artificial drainage system for the control of the groundwater table at a specified safe depth. ·Filter materials: These are sometimes placed around subsurface drains primarily to prevent the inflow of soil into the drains which may cause failure, and/or to increase the effective diameter or area of openings in the drains which increases inflow rate. Two types of materials are generally used: 1. Thin sheets such as of fibre glass or spun nylon and 2. Sand and gravel envelopes or other porous granular materials ·Pump drainage: The chief drawback of gravity drainage systems is their inability to lower the water table to an adequate depth. Pumping groundwater in areas where a suitable permanent aquifer exists is often an effective means of lowering the water table. Maintenance of Drainage SystemsA subsurface drainage system normally requires little maintenance if it is properly designed and installed. The outlet ditch should be kept free of the sediment and the tile outlet should be protected against erosion and undermining. If a drain line becomes filled with sediment or roots the line should be uncovered at some point downstream to locate the obstruction. Roots of nearby trees can also block subsurface drains. For this reason shrubs and trees growing adjacent to a tile line should be removed. Weed growth must be controlled and the caving in of the sides requires continuous attention in order that the entire drainage system continues to work efficiently. Conclusion Salt in soils comes from basic fertilizers, salty irrigation water and naturally-occurring salts. Salt build up is the result of a lack of effective leaching of salts through soils. Salt management in soil is a major challenge for growers. The challenge is to effectively manage soil salinity and sodium (Na) in a cost-effective manner, using appropriate combinations of irrigation management, soil management, and soil amendments. Popular Kheti ISSN:2321-0001 79 Kumar et al., 2013, Pop. Kheti, 1(1): 76-79
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