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Microbes as Biofertilizers and their Production Technology © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Microbes as Biofertilizers and their Production Technology Prof. S. G. Borkar WOODHEAD PUBLISHING INDIA PVT LTD New Delhi, India © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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CRC Press Woodhead Publishing India Pvt. Ltd. Taylor & Francis Group 303, Vardaan House, 7/28, Ansari Road 6000 Broken Sound Parkway NW, Suite 300 Daryaganj, New Delhi – 110002, India Boca Raton, FL 33487-2742 © 2015 by Woodhead Publishing India Pvt. Ltd. Exclusive worldwide distribution by CRC Press an imprint of Taylor & Francis Group, an Informa business No claim to original U.S. Government works Version Date: 20150519 International Standard Book Number-13: 978-93-80308-14-2 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources. Reason- able efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use. The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained. If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint. Except as permitted under U.S. Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers. For permission to photocopy or use material electronically from this work, please access www. copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc. (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400. CCC is a not-for-profit organiza- tion that provides licenses and registration for a variety of users. For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged. Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com For information about WPI Publishing visit their website at http://www.woodheadpublishingindia.com © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Contents Preface xiii Foreword xv 1 Introduction 1 2 Microbes as biofertilizers, their types and importance 7 2.1 What are biofertilizers? 7 2.2 Types of biofertilizers 7 2.2.1 Nitrogen-fixing biofertilizers 8 2.2.2 Phosphate solubilizing biofertilizers 39 2.2.3 Vesicular arbascular mycorrhizae 43 2.2.4 Potassium solubilizing biofertilizer 46 2.2.5 Sulfur oxidizing biofertilizer 50 2.2.6 Silicate solubilizing biofertilizer 54 2.2.7 Silica solubilizing bacillus sp. 58 2.2.8 Decomposting cultures 59 3 Rhizobium 63 3.1 Introduction 63 3.2 Isolation of Rhizobium 63 3.2.1 Materials 64 3.2.2 Procedure 65 3.2.3 Observations 66 3.3 Cultural tests to distinguish Rhizobia from contaminants 67 3.4 Estimation of ‘N’ fixing effi ciency of Rhizobium cultures 68 3.4.1 Apparatus 69 3.4.2 Procedure 70 3.4.3 Calculation 70 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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vi Contents 4 Azotobacter 73 4.1 Introduction 73 4.2 Isolation of Azotobacter from soil on selective Jonsen’s agar medium 73 4.2.1 By soil dilution and pour plate technique 73 4.2.2 By enrichment culture technique 75 4.3 Cultural test to distinguish Azotobacter from contaminant 76 4.4 Test for Nitrogen fi xation in pure culture of Azotobacter 77 4.4.1 Pure culture medium 77 5 Azospirillum 79 5.1 Introduction 79 5.2 Isolation of Azospirillum from soil 79 5.2.1 Procedure 79 5.3 Cultural test to distinguish Azospirillium from contaminant 80 5.4 Test for Nitrogen fi xation in pure culture of Azospirillum 80 5.4.1 Pure culture medium 81 6 Acetobacter diazotrophicus 83 6.1 Isolation of Acetobacter diazotrophicus 83 6.1.1 Materials 83 6.1.2 Procedure 84 6.1.3 Observations 84 6.2 Cultural tests to distinguish Acetobacter diazotrophicus from contaminatns 85 6.3 Test for nitrogen fi xation in pure culture of Acetobacter diazotrophicus 86 7 Blue-green algae 87 7.1 Isolation of blue-green algae from soil 87 7.2 Cultural tests to distinguish blue-green algae from contaminants 88 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Contents vii 7.3 Test for nitrogen fi xation in pure culture of blue-green algae 89 8 Azolla 91 8.1 Introduction 91 8.2 Isolation of Azolla 91 8.3 Factors influencing the biomass production of Azolla 93 8.3.1 Water 93 8.3.2 Temperature 94 8.3.3 Humidity 94 8.3.4 Light intensity 94 8.3.5 Wind 95 8.3.6 Soil pH 95 9 Frankia: N -fixing endophytes 97 2 9.1 Isolation of Frankia from actinorhizal nodules 97 9.2 Cultural test to differentiate Frankia from contaminats 98 9.3 Estimation of ‘N’ fixing effi ciency of Frankia 98 10 Phosphate solubilizing microorganism 99 10.1 Isolation of phosphate solubilizing microorganism 99 10.1.1 Materials 99 10.1.2 Pikovskaya’s medium 99 10.1.3 Procedure 100 10.1.4 Observation 100 10.2 Estimation of phosphate solubilizing ability of phospho solubilizer 100 10.3 Quantification of soluble phosphorus released by phosphosolubilizer 101 10.3.1 By using ammonium molybdate reagent 101 10.3.2 By using ascorbic acid reagents 101 11 Vesicular arbuscular mycorrhizae 103 11.1 Introduction 103 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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viii Contents 11.2 Isolation of arbuscular mycorrhizal fungal spores 103 11.3 Identification of VAM fungi 104 11.3.1 Spore morphology of VAM fungi 104 11.4 Inoculum production 105 11.5 Mycorrhizal dependency 106 11.6 Screening for effective isolates 107 11.7 Application of inoculum 107 11.8 Arbuscular mycorrhizal fungal colonization 107 11.9 Estimation of infectious propagule per gram of soil 108 12 Sulphur oxidizing microorganism 109 12.1 Isolations of sulphur oxidizing bacteria 109 12.2 Purification of sulphur oxidizing bacteria from enriched medium 109 12.3 Isolations, purification and maintenance of sulphur oxidizing fungi and actinomycetes 110 12.4 Screening of isolates for sulphur oxidizing efficacy 110 13 Silicate solubilizing biofertilizers 113 13.1 Introduction 113 13.2 Isolation and enumeration 113 13.2.1 Modified bunt and rovira medium 113 13.3 Testing of silicate solubilization potential 114 13.3.1 Basal medium 114 13.4 Estimation of available silica (Saxena 1989) 114 13.4.1 Reagents 114 13.4.2 Procedure 115 14 Potassium solubilizing biofertilizers 117 14.1 Isolation of potassium solubilizing microorganisms 117 14.1.1 Media composition 117 14.2 Testing of effective strains of KSM 117 14.3 Quantitative estimation of k released from insoluble k 118 14.3.1 Preparation of standard curve 118 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Contents ix 15 Composting culture 119 15.1 Isolation and maintenance of decomposting cultures 119 15.1.1 Materials 119 15.1.2 Procedure 119 15.1.3 Observations 120 16 Production technology of biofertilizers 123 16.1 Design for biofertilizer production unit 123 16.1.1 Laboratory 123 16.1.2 Fermentor room 124 16.1.3 Mixing and curing room 124 16.1.4 Packaging room 124 16.1.5 Storage room 125 16.2 Production technology 125 16.2.1 Materials 125 16.2.2 Procedure 125 16.3 Carrier-based biofertilizers 126 16.3.1 Preparation of carrier 126 16.3.2 Preparation of inoculants in powder form 126 16.4 Liquid biofertilizer 128 16.4.1 Production technology of liquid biofertilizers 128 16.4.2 Composition of liquid biofertilizer media 128 16.4.3 Procedure for liquid biofertilizer production 130 16.5 Production technology for blue-green algae132 16.5.1 Mass production of BGA 132 16.5.2 Recommendation for field application 134 16.5.3 Importance of Algal biofertilizers 135 16.6 Production technology of Azolla 136 16.7 On-farm production of arbuscular mycorrhizal fungi 136 16.8 Production technology of decomposting culture 137 16.8.1 Materials 137 16.8.2 Procedure 137 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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x Contents 16.9 Production of compost 138 16.9.1 Materials 138 16.9.2 Procedure 138 16.9.3 Precautions 139 17 Assessment of quality standards of biofertilizers 141 17.1 Introduction 141 17.2 Quality standards of Rhizobium and Azotobacter 141 17.3 Quality control measures (as per ISI specification) 143 18 Application technology of biofertilizers 145 18.1 Use of carrier-based biofertilzers 145 18.1.1 Seed treatment 145 18.1.2 Seedling treatment 145 18.1.3 Soil treatment 146 18.2 Use of liquid biofertilizer 146 18.2.1 Seed Treatment 146 18.2.2 Sett inoculation 146 18.2.3 Seedling treatment 147 18.2.4 Soil treatment 147 18.2.5 Soil broadcasting 147 18.2.6 Seed pelleting 147 18.2.7 Foliar spray 147 18.28 Drip irrigation 147 19 Advantages, limitations and constraints 149 19.1 Advantages of biofertilizers 149 19.2 Limitations 150 19.3 Constraints in biofertilizer production technology 150 19.3.1 Physical and environmental constraints 150 19.3.2 Chemical constraints 151 19.3.3 Biological constraints 151 19.3.4 Technical constraints 151 19.3.5 Infrastructure constraints 152 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Contents xi 19.3.6 Human constraints 152 Glossary 155 List of Medium 159 References 165 Subject index 195 Author index 197 © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Preface Agriculture plays a crucial role in Indian economy, accounting close to 17% of gross domestic product. More importantly, about 60% of India’s work force is dependent on agriculture and allied activities for their livelihood. Successive Five Year Plans on self-sufficiency and self-reliance in food grain production have resulted in substantial increase in agricultural production and productivity. The use of chemical fertilizers has played a vital role in the success of India’s green revolution and consequent self-reliance in food grain production. To achieve this, the fertilizer consumption in India increased from less than 1 kg/hector in 1951–1952 to 143.130 kg/hector in 2011–2012. The indigenous capacity of fertilizer production which was around 27 lakh metric tonnes during 2011–2012 in nutrient terms, remained almost stagnant for over more than one decade; and therefore, the government had to increase the import during 2013–2014 which was estimated to be around 80 lakh metric tonnes (80 LMT). Around 25% of our fertilizer requirements are met through this import. This increasing dependence on imports had serious implication on the economy. This dependence on inorganic fertilizers can be reduced by using the organic fertilizers like farmyard manure, compost, green manure, slurries, and more importantly biofertilizers. Biofertilizers can be used almost in all the crop plants, i.e. hydrophytes like paddy and sugarcane, mesophytes like most of the cereal, pulses, vegetables, and fruit crops, and zerophytes like pearl millet and medicinal plants. The research findings available show that the biofertilizers like Acetobacter can save up to 50% of nitrogen application in sugarcane, while in several other crops it can saves 20% nitrogenous application and increase the yield by 20%. When we considered the estimated import of nitrogenous fertilizers urea of 80 LMT, at least by application of biofertilizers, the import of 16 LMT of nitrogenous fertilizer can be reduced. Similarly with the use of P solubilzer, K mineralizer, and S oxidizer, the requirement of these nutrients can be accomplished. With the use of organic © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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sources like compost and biofertilizers, not only the nutrient supplements can be made available in soil but also the structure, texture, and soil health can be improved which has long implication on soil health and productivity. In the present day scenario, with continuous use of inorganic fertilizers, the soil fertility is eroded with changed physical/chemical structures and textures, accumulation of toxicants in soil, degraded soil biota and soil health with stagnant soil productivity. Therefore, the need of the day is to have integrated nutrient source system which includes inorganic, organic, and biofertilizers in all the crop production systems. As biofertilizers are cost effective, ready to use, and sustainable in soil ecological systems, their use should be encouraged in all the crop production systems to produce more healthy and organic food. Prof. S. G. Borkar © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Foreword The year 2015 has been declared by the United Nations as the International Year of the Soil. This is in recognition of the important role soil fertility and productivity play in meeting the Zero Hunger Challenge of the United Nations. When I was the chairman of the FAOs Food Security Committee, I got a Global Soil Partnership organised on the lines of the already existing Global Water Partnership. In our country, land is a shrinking resource for agriculture. Therefore, we have no option except to produce more from diminishing per capita availability of arable land. Soil hunger leads to crop hunger and thereby to human hunger. To provide all the nutrients needed for our crops through mineral fertilisers, we will require nearly 30 million metric tonnes of fertilisers. Such a large quantity will both be difficult to obtain and also ecologically not desirable. Therefore, we should promote integrated nutrient supply systems consisting of a mixture of organic manures like compost and cow dung manures, green manures, biofertilizers, and the minimum essential mineral fertilizers. It is in this context that the present book by Prof. S. G. Borkar and Dr. M. H. Shete of the Department of Agricultural Microbiology of Mahatma Phule Agriculture University is a timely contribution. Efficient microorganisms (also known as EM technology) are well known to be the main instruments for achieving an evergreen revolution leading to increase in productivity in perpetuity without ecological harm. I hope this book will be widely read and used. Biofertilizers and agricultural microbiology should occupy an important place in the programmes for the international year of soil. We thank Dr. Borkar and Dr. Shete for this labour of love in the cause of sustainable food security in our country. M. S. Swaminathan © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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1 Introduction A large proportion of humanity depends for its sustenance on the food production to which increase is brought about through the application of fertilizers to the crops. Fertilizers contribute to both the quantity and quality of the food produce when used in the right way; applying the right source at right rate, time and place and to the right crops (http://www.fertilizer.org). Fertilizers are as important as the seed; as evident in the green revolution (Tomich et. al. 1995), contributing as much as 50% of the yield growth in Asia (Hopper 1993 and FAO 1998). Others have found that one third of cereal production worldwide was due to the use of fertilizers and related factors of production (Bumb 1995). The global fertilizer industry produces some 170 million tonnes of fertilizer nutrients annually. These are used in every corner of the globe to support agricultural production and it is an essential ingredient in the drive towards food security (IFA 2014). Plants require three major and thirteen minor nutrients for their growth. Nitrogen, phosphorus and potassium are the three major plant nutrients and are supplied through inorganic fertilizers to the plants. It is estimated that annually 25.1 million tonnes of nutrients are removed from the soil, whereas only 15.0 million tonnes are supplied to soil including organics. The total demand of fertilizers as plant nutrient by the whole country cannot be made due to their unavailability. Import of fertilizers in India was about 2 million tonnes in early parts of the year 2000, which increased to 10.2 million tonnes in 2008–2009. India has the second largest fertilizer consumption in the world after China, consuming about 26.5 million tonnes every year. However, the average intensity of fertilizer use in India remains much lower than most countries in the world (Jaga and Patel 2012). The fertilizer consumption in India has increased from less than 1 kg per hector in 1951–1952 to 143.130 kg in 2011–2012. The indigenous capacity of fertilizer production which is presently 27 lakh metric tonnes in nutrient terms remained almost stagnant for more than one decade. The fertilizer production in our country does not fulfill the required demand (Table 1). © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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2 Microbes as biofertilizers and their production technology Table 1 Status of fertilizer requirements and production in India (million tonnes) Year 1996 2000 2011 2031 2051 Requirement 16.0 19.0 20.2 27.3 31.3 Production 12.8 14.9 15.8 20.9 23.9 And therefore, the government is increasing the import every year to meet the domestic requirement. Globally, the consumption of fertilizer-N increased from 8 to 17 kg per hector of agricultural land in the 15 years period from 1973 to 1988 (FAO 1990). Significant growth in fertilizer-N usage has occurred in both developed and developing countries (Peoples et. al. 1995). Import of urea as fertilizer-N in 2013–2014 is estimated to be around 80 lakh metric tonnes, roughly 25% of our requirement of urea alone. Around 90% of P and 100% of K requirements are met through import. Increasing dependence on import has serious implication on our economy. The requirement for fertilizer-N are predicated to increase further in the future (Subba-Rao 1980); however, with the current technology for fertilizer production and the inefficient methods employed for fertilizer application, both the economic and ecological cost of fertilizer usage will eventually become prohibitive. The problems associated with the use of chemical fertilizers are the adverse effects on the long term soil fertility, soil productivity and environmental safety (Kannaiyan 2000). Under these circumstances, alternate sources of fertilizers are to be explored. The atmosphere contains 78% of free nitrogen which accounts for about 1015 tonnes of N gas and the nitrogen cycle involves the transformation of 2 some 3 × 109 tonnes of N per year on a global basis (Postgate 1982). However, 2 transformations (N fixation) are not exclusively biological. World production 2 of nitrogen from dinitrogen for chemical fertilizers accounts for about 25% of the earth’s newly fixed N , and biological processes account for about 60%. 2 For more than 100 years, biological nitrogen fixation (BNF) has commanded the attention of the scientists concerned with plant mineral nutrition, and it has been exploited extensively in agricultural practice (Burris 1994; Dixon and wheeler 1986). However, its importance as a primary source of N for agriculture has diminished in the recent decades as increasing amounts of fertilizer N have been used for production of food and cash crop (Peoples et. al. 1995). However, international emphasis on environmentally sustainable development with the use of renewable resources is likely to focus attention on the potential role of BNF in supplying N for agriculture (Burris 1994; Peoples et. al. 1995). Currently, the subject of BNF is of great practical importance because the use of nitrogenous fertilizers has resulted in unacceptable levels of water pollution (increasing concentrations of toxic nitrates in drinking water © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Introduction 3 supplies) and the eutrophication of lakes and rivers (Al-Sherif 1998; Sprent and Sprent 1990). Further, it is usually applied in a few large doses and up to 50% of which may be leached (Sprent and Sprent 1990). This not only wastes energy and money but also leads to serious pollution problems, particularly in water supplies. To fill this gap, alternate sources of nutrients have to be looked for. Organic wastes and biofertilizers are the alternate sources to meet the nutrient requirement of crops and to bridge the future gaps. Further knowing the deleterious effects of using only chemical fertilizers on soil health, the use of chemical fertilizers along with organic wastes and biofertilizers will be an environment friendly approach for nutrient management and ecosystem maintenance. Such integrated approach will help to maintain the soil health and productivity, and thus should be advocated and popularized among the farming community. The availability and utilization of the crop nutrients is more important for the crop plants. The crops assimilate their requirement mainly through soil reserve, fertilizers and manure, precipitation and irrigation water and biological nitrogen fixation involving a number of divers groups of microorganisms. Biological nitrogen fixation offers an economically attractive and ecologically sound route for augmenting nutrient supply with the aid of microorganisms. Thus, Rhizobium for legumes; BGA and Azolla for several crops; P solubilizers, sulphur oxidizers, phosphate absorbers like vesicular arbuscular mycorrhiza (VAM) and organic decomposers plays a significant role in agriculture. All these are based on renewable energy sources and are eco-friendly. But one needs to be clear about the idea that biofertilizers alone can’t meet the total nutrient requirement of agriculture and in fact, it is one of the inputs that is to be used along with other inputs. Biofertilizer is a large population of a specific or a group of beneficial micro-organisms; millions and billions of them are incorporated aseptically into sterile carrier materials such as peat, lignite, or charcoal. Such material is thereafter packed and sold to the farmers as biofertilizers for enhancing productivity of soil, either by fixing atmospheric nitrogen or by solubilising soil phosphorous or by stimulating plant growth through synthesis of growth promoting substances. Biofertilisers are the low-cost source of plant nutrients, eco-friendly and have supplementary role with chemical fertilizers. The biofertilizers are bacteria, algae and fungi and may broadly be classified into two categories, viz. nitrogen fixing like Rhizobium, Azotobactor, Azospirilum, Acetobacter, blue- green algae and Azolla and phosphorous solubilizers/mobilisers like PSM and mycorrizae. Recently, the potash mobilisers like Frateuria aurentia zinc and sulphur solubilisers likeThiobacillusspecies and manganese solubiliser fungal © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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4 Microbes as biofertilizers and their production technology culture like Pencillium citrinum have also been identified for commercial operations. These new strains would also address the issue of “Fertilizer Use Efficiency” and would also enhance the efficacy of biofertilizers. The biofertilizers were initially identified by a Dutch scientist in 1888 and thereafter “Nobbe and Hiltner” produced the first biofertilizer under the trade name “Nitragin” in 1895 in The United States. The role of biofertilizers in agriculture production assumes special significance, particularly in the present context of very high cost of chemical fertilizers. In simple term, biofertilizers are the fertilizers prepared from bioagents containing live cells of bacteria or cyanobacteria or fungi which efficiently either fix atmospheric nitrogen, solubilize insoluble phosphate in soil, or decompose organic wastes. “Biological nitrogen fixation” is a reduction of molecular nitrogen to ammonia mediated by enzyme nitrogenase. It offers an economically attractive and ecologically sound route for augmenting nutrient supply with the aid of microorganisms. The biofertilizer production, in general, involves the selection of efficient strain of biofertilizer agent, growing it on a large scale in suitable nutrient medium, incorporating it in sterilized carrier and packing it in biofertilizer packets under strict aseptic conditions. There are over 100 biofertilizer units operational in the country. These units produced about 20,040 MT biofertilizers against the installed capacity of over 86,000 MT during 2009–2010. The year-wise capacity, production and sales trend of biofertilizers are given in the Table 2. Table 2 All India production and sales trend of biofertilizers (MT) Year Production Sales 2000–2001 6242.6 6138.6 2001–2002 7390.0 6876.1 2002–2003 8643.0 7000.0 2003–2004 10500.0 8500.0 2004–2005 10479.0 10428.0 2005–2006 11752.0 11358.0 2006–2007 15871.0 15745.0 2007–2008 20111.0 20100.0 2008–2009 25065.0 25000.0 2009–2010 20040.3 20000.0 Source: Specialty Fertilizer Statistics, FAI (2011), MOA and NCOF, Ghaziabad. © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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Introduction 5 The present day requirement of biofertilizers based on crop area for India is 5,50,000 metric tonnes; however, the total production in our country is hardly 20,000 metric tonnes. This necessitates the increase in biofertilizer production. The Government of India is encouraging the biofertilizer industry by providing subsidies to a maximum of 20 lakh rupees and awarding a national productivity award to the efficient biofertilizer production unit. Many state governments have also started self-employment oriented biofertilizer production training programmes. In future, it is hoped that the sufficient production of biofertilizers may be achieved through private, public sectors, and government institutes to meet the requirements. In contrast to the inorganic fertilizers, biofertllizers are applied to the seed and seedling and hence they are more effective. They secrete auxins and hormones thereby increasing the germination. Once the biofertilizers are applied, they cannot be leached out, evaporate, or be lost; but the biofertilizer microbes increase in number. Biofertilizer agents also exhibit fungicidal action. Application of biofertilizers does not affect the texture of soil, but improves the structure and texture. Biofertilizers increase nitrogen fixation, phosphate solubilization, sulphur oxidation and helps to supply other macro and micro nutrients to the plants for their growth and are essential for balanced nutrient supply. Similarly they increase vegetative growth, total dry-matter production, yield, and quality of the product. Biofertilizers are the essential soil inputs used in farming that help to develop and sustain soil texture and soil fertility. They are easy to use and can be used for all types of fruits, cereals, pulses, cash crops, vegetables, lawns, ornamental plants, and home-garden plants. The farmers all over the world are turning more and more towards biological agriculture, as they increasingly encounter the hazardous effects of chemical fertilizers and their prohibitive costs. Biological farming aims at preserving the natural and ecological balance according to the environmental standards. Therefore, biofertilizer is a most important component in agriculture farming system. © 2015 by Woodhead Publishing India Pvt. Ltd. ThiNganHang.com
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