eChapters

Abstract

Potassium is a very essential nutrient element that is required for proper health, growth, functioning and productivity of plants. However, up to 98% of this very important mineral is held up in insoluble, unavailable forms in the soil and with only approximately 2% soluble form available for plant use. Biofertilizers add nutrients to the soil for plant use by some mechanisms like the breakdown of phosphorus, potassium, fixing nitrogen, and also synthesizing some substances which in turn enhance plant growth. These processes take place naturally. Microorganisms that solubilize potassium have demonstrated an increased potassium uptake by plants when added as bio-inoculants consequently resulting in increased yield by these plants. This article reviewed the methods of isolation of potassium solubilizing bacteria and fungi and their use as biofertilizers. Data are presented showing summary of researches conducted on potassium solubilizing microorganisms and their findings. Figures on production efforts of biofertilizers in India per year and by states are also added.

Abstract

Nitrogen (N₂) is an essential nutrient for every organisms. It is the building block of many biological molecules. Atmosphere contains 79% of N₂ gas which cannot be used by plants directly as it is chemically inert. Many diazotrophs like bacteria and cyanobacteria have the capability to convert atmospheric dinitrogen into a usable form by means of Biological nitrogen fixation (BNF). N₂ fixation is generally three types i.e. Asymbiotic, Associative and Symbiotic. Asymbiotic N₂-fixation also known as free living N₂-fixation is under taken by some bacteria and cyanobacteria. In associative N₂-fixation, some bacteria fix nitrogen in association with root of some grasses and cereal plants. In symbiotic nitrogen fixation, Rhizobium form root nodule in legumes and fix atmospheric N₂ and convert it into the ammonia (NH₃) by the help of Nitrogenase enzyme. This oxygen sensitive enzyme consist of two components i.e. di-nitrogenase (MoFe protein) and di-nitrogenase reductase (Fe protein) which are highly conserve in sequence and structure. The N₂ fixing genes e.g. nod gene (nodulation gene) and the nif gene (nitrogen-fixing gene) are located in the plasmid which is also called mega plasmid. Symbiotic association between legume and rhizobium have agronomic importantance and reduce the use of N-fertilizers or even avoided. The long term use of the nitrogenous biofertilizer in the agricultural field is a promising approach to develop and fulfil N₂ demand of the growing crop without causing any environmental hazard.

Abstract

Sustainable agriculture is vital in today’s world as it offers the potential to meet our agricultural needs, something that conventional agriculture fails to do. Current soil management strategies are mainly dependent on inorganic chemical fertilizers, which caused a serious threat to human health and environment. To overcome the ecological problems resulting from the loss of plant nutrients and to increase crop yields in the absence of resources for obtaining costly fertilizers, microscopic organisms that allow more efficient nutrient use or increase nutrient availability can provide sustainable solutions for the present and future agricultural practices. Microbial populations are instrumental to fundamental processes that drive stability and productivity of agro-ecosystems. Several investigations addressed at improving understanding of the diversity, dynamics and importance of soil microbial communities and their beneficial and cooperative roles in agricultural productivity. Thus the technique, which uses microscopic organism as biofertilizer, is environment friendly and ensures safe and healthy agricultural products. In this chapter we aim to provide a brief overview of potential use of biofertilizer for attaining sustainability of agro-ecosystem.

Abstract

In recent years, significant studies have been carried out on Plant growth promoting rizhobacteria (PGPR) to replace the usage of pesticides and fertilizers to improve the plant health. Plant growth promoting rizhobacteria (PGPR) is a group of rhizosphere bacteria, which are symbionts to plants and influence their growth by providing plant growth promoting substances. Different bacterial genera act as plant growth promoting rizhobacteria (PGPR): Pseudomonas sp., Rhizobium sp., Azotobacter sp., Bacillus sp. Pseudomonads are gram negative rods, aerobic, fluorescent, motile and are able to produce siderophores which influence plant growth. There are multiple potential traits offered to the plants by plant growth promoting (PGP) Pseudomonas sp. are (1) Biocontrol agent against plant pathogens (2) Induced systemic resistance, which is a defense mechanisms in plants preceding to pathogenic attack (3) Influence of plant growth promoting (PGP) Pseudomonas sp.on agricultural crops (4) Siderophores, which are low molecular, high affinity iron chelating compounds which benefits the plants to acquire iron molecules (5) Nitrogen fixation (6) Phytoremediation of heavy metals (7) Solubilization of inorganic phosphates (8) Secretion of plant hormones (9) Bacteriocins(10) Antifungal factors (11) Antibiosis traits and (12) Endophytic PGP Pseudomonas sp.

Abstract

Soil salinity is one of the major environmental stresses affecting crop productivity and soil health drastically, particularly in arid and semi-arid areas. Most of the vegetable crops being salt sensitive, grow poorly in saline and alkaline soils. Soil salinity affects crops mainly due to the osmotic stress and excessive accumulation of toxic ions (Na⁺, Cl^-, and SO₄ ^2-), whereas alkali soils are generally characterized by poor physical conditions due to high concentrations of bicarbonate (HCO₃ ^-) and carbonate (CO₃ ^2-) as well as high exchangeable Na⁺. Excessive concentrations of sodium chloride (NaCl) in soil or irrigation water can induce several morphological, physiological, and biochemical responses in plants leading to stunted growth and yield. This is due to osmotic (i.e., water deficit) and ionic (i.e., Na⁺ and Cl^-) effects on nutrient uptake/translocation and metabolic processes such as nitrogen assimilation, photosynthesis, and protein synthesis. Plant growth promoting microbes (PGPMs) are considered as promising tools to overcome the limitations of salinity on crop growth and productivity. Many PGPMs can enhance tolerance of crops to salt stress by increasing nutrient uptake through better solubilization of nutrients like phosphorus and zinc, and also by production of small peptides, volatiles and metabolites with hormone activities such as indole-3-acetic acid or auxin analogs in the rhizosphere. This chapter discusses the benefits of PGPMs in plant adaptations to salt stress conditions.

Abstract

Agriculture is one of the most important factors contributing to the economic growth of India. Out of the 329 million hectares of India’s geographical area, about 114 million hectares are under cultivation. There are 17 essential elements required for proper plant growth. Of the mineral elements, the primary macronutrients (nitrogen, phosphorous, and potassium) are needed in the greatest quantities and are most likely to be in short supply in agricultural soils. Secondary macronutrients are needed in smaller quantities, and are typically found in sufficient quantities in agricultural soil, and therefore do not often limit crop growth. Micronutrients, or trace nutrients, are needed in very small amounts and can be toxic to plants in excess. Silicon (Si) and sodium (Na) are sometimes considered essential plant nutrients, due to their ubiquitous presence in soils.

The economy of India thrives on agriculture, the most practiced occupation in the country. Agricultural fertilizers are essential to enhance proper growth of plants and crop yield. Recently, farmers have been using chemical fertilizers for quicker and better yield. But these fertilizers endanger ecosystems, soil, plants, human and animal lives. In contrast, naturally grown biofertilizers not only give a better yield, but are also harmless to humans. This chapter aims to study the biofertilizers play a key role for enhancing economic development of sustainable agriculture (EDSA) in comparison to chemical fertilizers. Biofertilizers improve the crop yields, plant resistance, soil health, profit to farmers, and the benefit to cost ratio of biofertilizers were higher than chemical fertilizer, proved that the biofertilizers would lead to better sustainable economic development for the farmers and their country.

Abstract

The concern of global food security is growing day by day as the agriculturally available land is reducing each day with the expansion of industrialization and urbanization. During the course of urban and industrial development, crop production is greatly affected by global warming, contamination of hazardous materials, salinity and drought. To combat against such adversities, scientists have taken several additives measurement like development of transgenic crops, application of indigenous plant growth promoting microbes etc. for sustainable agriculture. Use of plant growth promoting microbes is getting popular day-by-day as they occupy a privilege niche with the autochthonous flora of specific environment. For the expanse of food and shelter, the microbes supply a wide range of plant regulators (e.g. auxins, cytokinins, gibberellins, ABA, phenols, NH₃ etc.), antibiotics, alkaloids, steroids, terpenoids, diterpenes, enzymes (e.g. cellulases, lipases, proteinase, esterases etc.) etc. for overall development of the plant. Apart from growth promotion, it also protects the plants against pathogenic invasion creating a competition with pathogens for nutrition and habitat. In near future, formulation of different plant growth promoting bacteria (like alpha- Azorhizobium, Azospirillum, Ancylobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Novosphingobium sp., beta- Burkholderia sp., gamma- Acinetobacter, Aeromonas, Azotobacter, Enterobacter, Klebsiella, Pantoea, Pseudomonas, Stenotrophomonas sp. Proteobacteria, Bacillus sp., Paenibacillus sp. and Actinobacteria- Microbacterium sp. etc.) and fungus (Aspergillus, Trichoderma, Penicillium etc.) may reduce the use of pesticides and chemical fertilizer to promote greener ways of crop production.

Abstract

Microbes are ubiquitously found in the environment. Their interaction with other living organisms could either be pathogenic or beneficial in nature. Soil as a rich source of microbes, researchers have extensively studied the plant-microbe interactions. The soil microbes supply the nutrients deficit plants with essential growth elements such as nitrogen, phosphorous, potassium, etc. and improve the texture and quality of the soil. Due to the destructive nature of chemical fertilizers to soil and environment, it was required to generate a more ecofriendly means of increasing the soil fertility. This led to the development of microbes based biofertilizers. The primary benefit of biofertilizers is to promote a healthy soil environment along with supplying essential nutrients to the plant. Again, biofertilizers can be tailor-made according to the specific plant or the climatic conditions. Fungal and bacteria based biofertilizers, either alone or in combinations are formulated for the plants. Lately, liquid fertilizers are increasingly finding their use in the biofertilizer industry due to their ease in manufacture and prolonged effect on plant growth. The scope of this chapter lays on the currently popular biofertilizers and recent trends in the biofertilizer industry.

The Fertilizer (Control) Order

The Fertilizer (Control) Order (FCO) is a set of legally enforceable executive orders issued by the Govt. of India under the Essential Commodities Act, 1955 passed by the Parliament. This order came into force in 1957, essentially to regulate the sale, price and quality of fertilizers in India. Amendments are made from time to time as per the exigencies and need of the hour and therefore a large number of amendments were made over a period of time. Consequently, after an overall review of the various provisions of the order, a revised Fertilizer (Control) Order 1985, was issued, which came into effect on September 25, 1985. The FCO consists of five Schedules comprising of different activities as mentioned in Figure 8.1, besides forms of registrations and appendices.

Schedule I comprises Part A and B. While Part A contains the specifications of different fertilizers (e.g. minimum nutrient content, maximum moisture content, range of physical parameters, maximum levels of impurities/ contaminants, etc.), that can be marketed in India (no material not performs the specifications as in the FCO cannot be sold as fertilizer), Part B lists the tolerance limits in plant nutrients and physical parameters for various fertilizers. Schedule II encompasses again two parts, with Part A describing the procedures for drawal of samples of fertilizers, and Part B describing detailed methods of analysis of fertilizers.

Schedule III encompasses four parts namely, Part-A, Part-B, Part-C and Part-D. While Part-A contains specifications of different biofertilizers, Part-B contains tolerance limits of biofertilizers, Part-C describes the procedures for drawal of sample of biofertilizers, Part-D describes the methods of analysis of biofertilizers. Schedule IV also encompasses four parts. Part-A contains specifications of organic fertilizers, Part-B contains tolerance limits of organic fertilizers, Part-C describes the procedures for drawal of sample of organic fertilizers, and Part-D describes the methods of analysis of organic fertilizers. Schedule V also contains of four parts. Part-A contains specifications of non-edible de-oiled cake fertilizers, Part-B contains tolerance limits of non-edible de-oiled cake fertilizers, Part-C describes the procedures for drawal of sample of non-edible de-oiled cake fertilizers, and Part-D describes the methods of analysis of non-edible de-oiled cake fertilizers.

Fertilizers have played a pivotal role in enhancing food grain production in India especially after the introduction of high yielding and fertilizer responsive crop varieties during the green revolution era. However, there are certain problems associated with fertilizers because of their relatively low nutrient use efficiency (NUE) or nutrient uptake by crops. The fertilizer use efficiency is 30-50% for N, 15-20% for P, 70-80% for K and 8-10% for S. In case of micronutrients, the use efficiency is only 1-2%. The low NUE is typically the result of higher release rate of fertilizers than the absorption rate by plants, and/or transformation of fertilizers/ nutrients to forms that are not bioavailable to crops.

Application of N and P fertilizers at levels exceeding plant requirements due to low acquisition efficiency leads to significant environmental consequences in many parts of the world due to losses, such as nitrate (NO₃^-) leaching, NH₃ volatilization, and nitrous oxide (N₂O) emission. Excessive use of fertilizer N affects the groundwater. Similarly, excessive use of N and P fertilizers leads to surface runoff which in turn causes eutrophication in aquatic ecosystems. These negative environmental consequences associated with fertilizer inputs further emphasize the need of technological approaches to improve nutrient management in modern agriculture. As such, there is great need in developing innovative fertilizers to minimize the losses of nutrients and increase their efficiencies.

In addition, current agricultural activities contribute up to 20-30% to the annual atmospheric emissions of greenhouse gases (GHGs), such as methane (CH₄) and carbon dioxide (CO₂). Even higher contribution is being noted for N₂O (about 60%), which is a potent GHG and catalyst for stratospheric ozone depletion, with more than 300 times the global warming potential than CO₂. Its emission is closely related to mineral fertilizer input. High fertilization rates lead to N and P losses with negative impacts on atmospheric GHGs concentrations and water quality.

There is an urgent need to improve NUE in agricultural systems, and to manage biogeochemical cycles in a sustainable way. This includes the development and application of modern technology as alternatives to conventional fertilization. There is a need to reduce the use of fertilizers/nutrients in agricultural systems by increasing NUE. The recent development in smart fertilizer delivery systems including nanofertilizers or the new generation fertilizers is a good alternative to commercially available fertilizers to improve the NUE and enhance resource utilization. Smart fertilizers may be a solution to enhance food production and environmental quality.

Iron (Fe), zinc (Zn), copper (Cu), manganese (Mn), nickel (Ni), boron (B), molybdenum (Mo) and chloride (Cl) elements are known as micronutrients. The micronutrients are also called as trace elements or minor elements as they are required very small quantities by plants. The elements Fe, Zn, Cu, Mn and Ni are known as micronutrient cations and B, Mo and Cl are known as micronutrient anions and they behave accordingly in soils. Among these elements, Fe content in soil as well as plant is the highest and sometimes higher than phosphorus (P) and sulphur (S). In plant, the concentration of micronutrients often found up to 100 mg kg^-1, except that of Fe and Mn which may go up to 500 mg kg^-1 (dry weight basis). Another element, cobalt (Co) is also regarded to be essential for the growth of certain higher plants and animals, and likely to be included in the list of micronutrients. The importance of micronutrients has been realized during the past four decades when micronutrient deficiencies were observed in most of the soils in our country, where intensive agriculture is practiced.

5.1. Importance of Secondary Nutrients in Agriculture

Secondary nutrients such as sulphur (S), calcium (Ca) and magnesium (Mg) are the macronutrients that are required in relatively large amounts for crop growth. Among the secondary nutrients, Ca is the 5^th most abundant element in the earth’s crust while, Mg and S are ranked 8^th and 13^th, respectively. The average S content of the earth’s crust ranges from 0.06 to 0.10%; whereas, Ca in soil solution of temperate region soils is 30 to 300 ppm and soils of tropical areas is 8 to 45 ppm (Tisdale et al., 1997). In case of Mg, its’ concentration ranges from 5-50 in temperate region and 120-2400 ppm in tropical region. The Ca and Mg are the most abundant cations occupying the exchange sites of the soil colloids. Thus, most soils with the possible exception of highly weathered, leached acid soils, contain enough Ca and Mg for crop growth. In soils, occurrence and reactions of S are different from those of Ca and Mg. The plant available S is SO₄^2- ion which is relatively mobile in soil solution. Like nitrogen (N), S is also subjected to chemical and biological oxidation-reduction reactions. On the other hand, Ca and Mg are much more stable and they exist in soil as Ca²⁺ and Mg²⁺ cations and present in association with soil colloidal fraction similar to that of K. In general, Ca and Mg are the most abundant cations occupying in the exchange site.

Secondary nutrients in soils may be lost due to several reasons such as (i) crop removal, (ii) leaching, (iii) erosion, and (iv) volatilization. The amount of Ca and Mg attain importance in areas where soils are either strongly alkaline or acidic. These soils are often deficient in Ca and Mg. The Ca deficiency is most widespread in acidic soils. The alluvial soils of the Indo-Gangetic Plains (IGP), being neutral to moderately alkaline in reaction, have sufficient bases on their exchange complex and Ca deficiency is, therefore, rarely found in these soils. However, alkali soils may contain inadequate quantities of Ca due to dominance of Na⁺ on the exchange complex. Magnesium deficiency is found in sandy soils with low exchangeable Mg²⁺, acid soils and those with high in native or applied K. Alkali soils have high exchangeable Na⁺. The Ca²⁺ is a suitable ion to replace this Na⁺ from the exchange complex when Ca²⁺ is supplied through gypsum (CaSO₄.2H₂O). The replaced Na⁺ forms Na₂SO₄ which is then leached down to remove the salt away from the root zone of the crops. Gypsum also reacts with Na₂CO₃ to form CaCO₃ and Na₂SO₄ which is leached down the profile. A thorough leaching of the soil with irrigation water should be done after application of gypsum to free it from Na₂SO₄.

Potassium is the third important essential nutrient element after nitrogen (N) and phosphorus (P) required by all living organisms, including plants and animals. Potassium is essential for many metabolic activities like carbohydrate metabolism, nitrogen metabolism. It is required for the activation of over 60 enzymes in plants. It controls/regulates the activities of various essential nutrients. It is vital to photosynthesis, and synthesis of carbohydrates, starch and proteins in plants. It plays vital role in controlling the opening and closing of stomata in photosynthesis. It also helps in controlling water use by plants by regulating the osmotic pressure of guard cells during transpiration. It plays a major role in transport of water and nutrients throughout the plant in xylem. Potassium improves crop yield and quality of flowers, fruits, vegetables and other field crops in terms of size, shape, colour, taste, shelf-life, and fibre quality. Potassium stimulates the growth of strong stems and provides strength to the plant against some disease by promoting thickness of the outer cell walls. It is required for translocation of assimilates. Under reduced K supply, translocation of NO₃^-, PO₄^3-, Ca²⁺, Mg²⁺ and amino acids is hampered. It also imparts resistance against environmental stresses such as drought, cold and frost. Adequate K can reduce moisture loss from growing plants, thereby giving some drought resistance. It reduces lodging of crops and enhances their winter-hardiness.

It is taken up by the plants as K⁺. Being a basic element, it takes part in neutralization of the acidity in plants caused by several organic acids produced. It does not form organic compounds in the plant system. It is the most mobile element in the plant. Thus, it can move through all the plant system due to osmotic pressure. When any plant sample is dipped into water, some K comes out. This shows that it is highly mobile.

Potassium is also required for animal nutrition and human beings. Potassium is essential for many metabolic functions. It maintains salt balance between cells and body fluids. Adequate K is essential for nerve function and preventing muscle cramps. It is routinely added to many animal feeds. Since K⁺ is not stored in the human body, dietary replacement is required on a regular basis. Government agencies state that diets containing foods that are good sources of K and low in Na may reduce the risk of high blood pressure and stroke.

Phosphorus (P) is the second most important essential nutrient limiting crop/ plant growth, next only to nitrogen (N). Phosphorus is an important component of nucleic acid like deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is needed for energy storage and transfer, which is the single most important essential function of P. Phosphate compounds act as “energy currency” within plants. The most important common P energy currency is adenosine diphosphate (ADP) and adenosine triphosphate (ATP). The ATP transfers energy for synthesis of ADP. Life is not possible without P. It is the source of energy that powers practically all energy-requiring biological processes in plants. Phosphorus is present in plant as phospholipid such as lecithin and cephalin which appears to be involved in the structural framework of protoplasm. Phosphorus is involved in many important processes such as photosynthesis, cell division, tissue development, and growth in plant. Requirement of P by the crops is less, compared to N and potassium (K). It is present in plant tissues. It is reported that for 5-6 t ha^-1 of wheat grain yield, it removes about 100-120 kg N, 20-30 kg P₂O₅ and 150-180 kg K₂O from soil.

Phosphorus is 11^th most abundant element on the earth crust. However, it is the least mobile element among the major plant nutrients. Its complex chemistry in soil makes it highly deficient nutrient element in most of the arable soils across the globe. Only 0.1% of the total P in the soil is available for uptake by plants because of its fixation as various insoluble compounds depending upon the soil pH. About 43% of the world’s arable soil is P deficient which limits crop growth and production (Roy et al., 2018). In the Indian context, about 80% of the soils are reported to have low to medium available P content (Muralidharudu et al., 2011). Thus, application of P-fertilizers to maintain the soil fertility and sustain crop productivity becomes imperative in today’s input intensive agriculture.

Nitrogen (N) is an essential element for all forms of life because it is a major component of amino acids, which are the building blocks of proteins, nucleic acids such as deoxyribonucleic acid (DNA) and other cellular constituents. It is a structural component of chlorophyll in plants, which is used in photosynthesis to make their food. Nitrogen ranks first among the essential nutrient elements required for plants. Its careful management is very important for crop production.

Nitrogen exists as two main stable isotopes (isotopes of a given element have the same number of protons but different numbers of neutrons in each atom) namely, ¹⁴₇N (abundance 99.63%) and ¹⁵₇N (abundance 0.37%). These can be separated by chemical exchange or by thermal diffusion. Both ¹⁴₇N and ¹⁵₇N isotopes of N are stable isotope which do not disintegrate as in case of other radioactive isotope like ³² ₁₅P. There are four other isotopes of N viz. ¹²₇N, ¹³₇N, ¹⁶₇N and ¹⁷₇N, mostly are radioactive having very short half-life and not used in agriculture. The ¹³₇N has a half-life of about 10 min, while other three have half-life of only few sec. The ¹⁵₇N (tracer) isotope is used as a tool for determination of pathways of transformation of N in soil or plant or animal.

The major part of N comes from atmosphere (air). On the basis of volume by volume (v/v), air contains about 78-79% N₂, 20-21% oxygen (O₂) and 0.03% carbon dioxide (CO₂). Most living organisms cannot utilize N₂ gas present in the atmosphere directly because it is present as di-nitrogen form or di-atomic form (N≡N). It is called as an inert gas. Therefore, to break this triple bond, huge amount of energy is required. After breaking of triple bond of N₂ molecules, it combines with other element particularly with O₂ or hydrogen (H) to form oxides of N (NO, NO₂, NO₃ and N₂O) or ammonia (NH₃). Thus, breaking of triple bond is must for forming NH₃ which further can be used as the key material for almost all fertilizers. Therefore, the fixation of N₂ is vital for production of all nitrogenous and complex fertilizers like NP/NPK and nitrophosphates.

Plant absorbs large number of elements from the soil and other sources during their growth and development. But all these elements are not essential for plant growth. Seventeen mineral elements are known to be essential for the growth and development of all plants. A list of essential nutrients, their source and forms by which they are absorbed by plants are presented in Table 1.1.

Except carbon (C), hydrogen (H) and oxygen (O), all the other nutrients are obtained by plants largely from soils, fertilizers or manures. It has been seen that the number of nutrients obtained from soil is about 5 times the number of nutrients obtained from air and water. However, most of the plant tissue, in general, from 74 to 99.5% is made up of C, H and O i.e. nutrients obtained from air and water and only 0.5 to 26% of the plant tissue is synthesized from soil constituents. In ordinary (normal) conditions of agriculture, except drought, C, O and H are not limited for plant growth. It is the remaining 14 elements from soil that are usually limiting plant development and hence considerable emphasis is placed on the improvement of soil in respect of greater availability of these 14 nutrients. It may be borne in mind that all nutrients are essential for all crops even though their requirements differ from crop to crop and even among varieties of a given crop. Secondly, all nutrients are equally essential regardless of amounts required. For example, to produce one tonne of grain, wheat may absorb 25, 9, 33, 3.7, 5.3 and 4.7 kg of nitrogen (N), phosphorus (P), potassium (K), sulphur (S), calcium (Ca) and magnesium (Mg), respectively and 56, 624, 70, 24, 48 and 2 g of zinc (Zn), iron (Fe), manganese (Mn), copper (Cu), boron (B) and molybdenum (Mo), respectively. If the crop (any crop) does not get the smallest amounts of micronutrients needed, it cannot make the best use of abundant NPK.

According to Liebig’s Law of minimum which he enunciated in 1855, the growth of a plant is limited by that nutrient which is in shortest supply. This law in fact lays the ground rules for balanced crop nutrition.

Soil fertility is the resultant of several factors, not the least important of which is the soil itself. Theoretically, the soil only plays the part of a support and could be very easily dispensed with and replaced by sand and even that can be replaced by a wire framework to support the plant mechanically and it will grow quite well if the right amount of nutrient materials have been added to water. ‘Where does the soil come in?” you will ask. The importance of the soil is two-fold: (1) It provides vast reserves of plant food which is slowly made available. (2) It provides limiting factors which restrict plant growth; these limiting factors must be neutralized. We have already discussed these reserve food materials and limiting factors in Chapter II.

It has been shown that if we treat a soil with dilute acid exhaustively we can remove everything from it except the mineral framework. If we try to grow anything in this mineral framework nothing will grow. Yet it is not like sand, for whereas in sand by adding appropriate amounts of nutrient materials in water solution you could grow a crop, nothing will grow if you added the same solution of nutrient materials to the soil. This mineral framework, therefore, is not inert like sand, but it is active and can react with the nutrient salts in such a way that either they are rendered unavailable or something else which is toxic is produced by the interaction between the soil and the nutrient salts. This mineral framework is not acted upon by dilute acids, but it reacts with alkalies in such a way that the alkalies are neutralized. In this respect, therefore, the mineral frame work behaves like an acid. With alkalies it forms salts and different alkalies are required in equivalent amounts for the formation of these salts. Thus we can have salts of a number of bases and if we use sodium hydroxide for neutralizing we shall have sodium soil, similarly we can have a calcium, magnesium or potassium soil. Now in nature, all the various bases principally, calcium, magnesium, sodium, and potassium, are associated with it in different proportions. The nature and amount of these bases determines the physico-chemical properties of the soil affecting crop yield and leading to soil infertility. We have already indicated the method of bringing the soiil to the normal state when it suffers from any of the defects associated with the soil framework.

Soil mechanics as a distinct branch of soil science is comparatively of recent growth. Its need arose from the fact that the requirements of the engineer are very often quite different from those of the agriculturist. Whereas the former would as a rule require hard, compact, impervious soil, the latter would have no use for it for the growth of his plants which require soft, friable and porous soil. The agriculturist generally has to look up to nature to help him out of his difficulties, the engineer has to depend on his scientific skill to modify the soil to suit his requirements. In this chapter an attempt will be made to explain in a simple language the requirements of the building, road, and irrigation engineer for particular types of soils and how they are met by modifying the soil if the required properties already do not exist.

Moisture plays by far the most important role in soils as regards vegetation. It is through the medium of water that the plants obtain their quota of mineral food vital for their growth. If water is gradually withheld from the soil, at a certain stage, the plant will begin to wilt and soon dry up. The soil may still contain some moisture but the plant is unable to make use of it. The minimum moisture in the soil below which wilting will take place is called the Wilting Coefficient and at one time great importance was attached to it. The determination of this Coefficient, however, is tedius. One must grow a number of plants and slowly watch them wilt and determine the moisture content at that point. Moisture content of the soil is determined by heating a weighed quantity of the sample in an oven kept at 100-110 ^oC. The moisture is expressed as percentage on the oven-dry soil.

Soil texture and mechanical analysis: The chemistry of the mineral framework was explained in Chapter II. Its physical properties are quite as important- When all the extraneous matter is removed from the soil we are left with a collection of particles of various sizes. These particles are not spherical in shape, but most of them are nearly so. At any rate the discussion is very much simplified if we suppose that they are spherical and the arguments advanced are equally applicable if the shape deviates from the spherical.

Next to the mineral frame work the salts in the soil deserve consideration. In fact these salts constitute the main food material of plants besides what the root hairs can get out of the mineral framework in the form of basic materials already dealt with. We are, however, not concerned with the plant food materials, but salts that are in excess and which alter the properties of the soil to such an extent as to influence its behaviour profoundly.

If the reader has endeavoured to follow the basic chemistry in the first chapter, he would be in a positions to follow up the various reactions that take place in soils and which hitherto had baffled him. Soils contain particles of various sizes ; some so fine that they would remain suspended in water for a long time; others so coarse that they would be sieved out by even a coarse sieve. Soils contain some salts that can be washed out by leaching with water; they contain some water which can be readily evaporated away by exposing to hot sun or by heating slightly. They also con-tain a little organic matter which can be burnt away or dissolved in alkali. When all the extraneous substances have been completely removed we are left with what we might call soil framework. This framework gives mechanical support to the roots of the plants. Without this framework the plant would not stand up even if it could be supplied with all the food material.

Let us suppose a soil freed from all the extraneous matter by continuous leaching with water or a dilute acid. In the former case the removal of all the extraneous matter is extremely slow, whereas by leaching with dilute acid everything except the soil framework is removed in a short time.

When soils from different localities are subjected to leaching with dilute acid we find that the soil framework in every case, behaves in a similar manner. No matter from what part of the world the soil has been obtained, the properties of its mineral framework only differ in quantity but not in kind.

For the intelligent appreciation and understanding of various reactions and processes associated with soils a little basic knowledge of chemistry is helpful. If the reader follows this chapter carefully, the working knowledge of chemistry thus acquired will enable him to follow all the complicated chemical reactions taking place in the soil.

What is Chemistry? Chemistry is the science that deals with the chemical changes. What is a chemical change? When two or more substances combine to give a substance entirely different in properties to the individual components, the change is called a chemical action to distinguish it from the purely physical action in which the properties of the product are intermediate between the components. The latter naturally can be separated easily by mechanical means. For instance a mixture of sand and water can be separated by passing through a filter, and a mixture of salt and water can be separated by evaporating the water when the salt is left as residue. But water itself is a compound of two gases: oxygen and hydrogen. Its properties are totally different from its components. We can freeze it, evaporate it and perform a host of other operations on it without changing it in the least.

Atoms and molecules: The whole science of chemistry rests on atoms and molecules If these are understood clearly, basic chemistry is reduced to simplicity. Take a familiar object like gold or silver and go on subdividing it into smaller and smaller bits. You will reach a stage that further subdivision will become impossible. You will have reached the primary units, the elementary bricks of which the substance is made up, namely the “Atoms”. An atom in chemistry is the smallest brick from which all material substances in the world are made up. Not that you can see an atom. It is so small that even the most powerful microscope will nut reveal its presence. You could perhaps just see a collection of a million atoms as a tiny spot of light if it is illuminated with a powerful beam of light. Even then you could not say if it was round, square, or oblong. However, you need not look for any such tangible proof to believe in the existence of atoms. Even pure logic would compel you to stop somewhere if you started with an imaginary division and sub-division of a substance. You could not go on ad infinitum. Even the ancients, who knew no modern chemistry, believed in their existence purely from philosophical reasoning.

The various adverse effects of Shifting cultivation, the need for its replacement have been widely discussed at various levels. It has been a matter of concern not only for the Government of India and the Planning Commission but also to the various state governments and the union territories of the region. Although considerable data on the extent of Shifting cultivation and its various adverse effects including its effect on agricultural production have been discussed in various forums, yet detailed scientific studies on shifting cultivation from various angles were not taken up until recently. The prevalence of shifting cultivation is so extensive in the region that it would not be possible to tackle the problem within a short period of time whatever, large the efforts may be. It will, thus, be necessary to approach the problem so that alternative systems of farming can be introduced in areas where the cycle of rotation has been greatly reduced.

Agriculture is an important economic activity for a large population of the developing world. The view that industrialization is the main hope of the developing countries has undergone remarkable changes in more recent times. Today, agriculture and rural development are viewed as the sine qua non of national development. A reorientation where in rural development is well balanced with industrial growth is now considered essential to correct serious imbalances in the economy, for equitable distribution of wealth and for social justice. It is against this background that increases in agricultural production in the developing world need to be viewed and evaluated.

Introduction

Shifting cultivation, developed over centuries of experience is known as “Swidden”, “Slash-and–burn agriculture”, “Rotational bush-fallow agriculture.’ or by a variety of local names; in India, it is commonly referred to as Jhum cultivation. This farming system is believed to have originated in the Neolithic period around 7000 B.C. This is the most primitive form of agriculture and is still common amongst the tribal people in various pockets. Shifting cultivation is mainly confined to medium to high rainfall zones between 100 meters and 2,000 meters above sea level. It is practised in three types of vegetation, such as forests, bush and grasslands.

Since seed deterioration is irreversible process and the rate of deterioration might be arrested using proper packaging material, moisture proof packaging material are very effective for preserving seed viability, germination ability, vigour and other quality traits of orthodox seed. For the locations, with inadequate storage facilities and high humidity, moisture proof material is favoured. The use of high cost material is justified considering the advantage under such conditions in terms of maintaining the quality of the seeds.

In hills, farmers usually store their own seed for sowing in the next season. The uncertainty about the availability of good quality seed at proper time in the remote hilly areas develops a habit in the farmers for storing their own seed. This chapter attempts to highlight the different methods/sources of packaging of seed and their relevant advantages and limitations.

Among different containers polyethylene bags appear to be promising packaging material for storage since it is effective in preserving seed viability longer, are easily available, less expensive and need less space for storage.

“Biodiversity, the planet’s most valuable resource, is on loan to us from our children.”

The significance of Plant Genetic Resources (PGR’s) is on top of agenda of all those who are concerned with food, nutritional and environmental security by using the Earth’s plant - biodiversity judiciously in a vital form. Agro-biodiversity is the backbone of a nation’s food security and the basis of economic development as a whole. The top-down system of agricultural research, where farmers are seen merely as recipients of research rather than as participants in it, has contributed to an increased dependence on a relatively few plant varieties. Global cooperation from farmers to agricultural scientist is critical for maintaining the balance across the agricultural landscape. Over the years this diversity in India is under pressure due to the massive commercialization of agriculture leading to the almost extinction of traditional farming systems and plant- biodiversity is under immediate threat. Behind this commercialization there lies the interest of the breeders for obtaining intellectual property rights. Around 1.6 billion people depend on farm-saved seed, yet up to 75 per cent of varieties of some key crops have already been lost this century. The rate of loss may well increase as global trade rules, intellectual property rights regimes, the concentration of agricultural research and development on inappropriate technological‘solutions’, and now the introduction and promotion of genetically engineered products, all combine to erode local resources from the fields of smallholder farmers. At the moment, it should call for a balancing on research into modern biotechnology, in favour of a redirection of research and development resources into sustainable, environmentally-friendly technologies that, sustain poor people’s livelihoods, agricultural biodiversity and agro-ecosystem functions. In this context, the importance of farmer-derived Agricultural Biodiversity that includes the variety and variability of plants and micro-organisms which are necessary to maintain the structure, processes and key functions of the agricultural ecosystem for, and in support of, food production and food security.

Underutilized crops can be found in many different agricultural ecosystems, but they are mainly grown by small landholders in the marginal areas especially in hill agriculture. Some crops remain underutilized because they are in some way not competitive with other species in the same agricultural environment. They are usually characterized by having local importance in consumption and production systems, requiring relatively low inputs, adapting to specific agro-ecological niches, receiving scarce attention by national agricultural and biodiversity conservation efforts, mainly consisting of local types or landraces, and being cultivated with indigenous knowledge. Many underutilized species are adapted to low-input agriculture and depended on by a large number of people in marginal areas in hill agriculture of developing countries.

This chapter attempts to provide a detail picture of one such underutilized crop i.e. Grain Amaranth. In an effort to explain the decrease in grain amaranth cultivation, fanciful myths have arisen. The mystery is especially intriguing when one considers that maize, with which amaranth co-evolved, was selected and developed into a major world crop. The small seed size of amaranth may have been a partial cause for the reduction in amaranth cultivation. A small seeded crop, such as amaranth, requires greater attention to detail in the early parts of the growing season than does a larger seeded crop, such as maize.

This chapter discussed all the factors related to its cultivation, the constraints in the production and importance of grain amaranth in the economy of hill agriculture etc.

Sustainability in agriculture is the prime importance for maintains its productivity particularly for crops over time and space. Sustainable agriculture is a system of farming as well as a philosophy which has its roots in a set of values that reflects an awareness of both ecological and socialrealities. It includes design and management procedures that work with natural processes to conserve all resources for maintaining or improving farm profitability keeping least waste and environmental damage.

The influence of environment on Indian farming revealed that future agricultural growth and productivity will have to occur simultaneously with environmental sustainability. The environmental challenges (land degradation, groundwater depletion, water logging and excessive use of chemical inputs) are posing problems for the future of Indian agriculture. Organic farming included in the policies has emphasized the sustainability in agriculture. Various other approaches and policy instruments, however, will be required to address these problems. The shift from input-intensive to sustainable, particularly organic farming is a difficult task as it involves a number of policy measures dealing with a variety of issues ranging from the transfer of information and technology to the development of markets. Another difficult task, and perhaps more difficult, relates to marginal and small farmers – which comprise a substantial part of Indian agriculture. Although, the marginal and small farmers considered as organic by ‘default’, severe resource constraints makes the shift to the modern sense of organic farming prohibitive.

Livestock manure is principally composed of organic material. When this organic material decomposes in an anaerobic environment, methanogenic bacteria produce methane. These conditions often occur when large numbers of animals are managed in confined areas (e.g. dairy, swine, and poultry farms, and beef feedlots, where manure is typically stored in large piles or disposed off in storage of lagoons or tanks).

Manure management will always be a part of livestock production. Management practices will have a significant impact on the environment regardless of the size of the operation. Producers who make wise manure management decisions help to maintain a healthy environment now and for generations to come. To reduce the risk of air or water quality damage from manure, understand how manure impacts air and water quality, keep the public in mind when locating, expanding or maintaining a facility, reduce the amount of material entering the waste stream, collect and store manure to preserve nutrients and minimize gas/odour emissions, apply manure to fields in a way that most fully utilizes the available nutrients, follow compositing to increase manure value, establish bio-gas unit as an alternate energy source and for the electricity generation and if possible integrate with fish production to augment income.

Based on the observations a model system of waste management was designed by systematic and scientific integration of a bio-fuel unit, settlement and slurry processing unit, aerobic composting, traditional composting, and preparation of value added products like Panchagavya, Jeevamritham, packed dried dung and fresh cow urine. There were no reports of odour or water pollution from nearby water sources. The overall results of the waste management indicated that this integrated system can be recommended as a model for waste management in dairy enterprises with beneficial effects on economic efficiency, environmental hygiene and quality control.

Although the efforts to develop hill agriculture were initiated in early fifties, planned development programme came to be evolved only in the late sixties. The phenomenal increase in food grains called the ‘Green revolution’ bye passed these hilly regions because of paraphernalia of constraints. Furthermore severity of soil erosion and soil degradation is much more and widespread in hill agriculture due to fragile ecosystem and its impact on plains through downstream sedimentation and flooding. Because of these constraints, traditional agriculture cannot be the lead sector for development. Thus the country faces the challenge of promoting livelihoods to minimize migration through local employment and income generation, and to enhance the quality of life of people living in villages. The positive features of these hilly areas are that they are rich in biodiversity, have enormous potential for tourism, a suitable climate for high value crops that can be harnessed for a development strategy.

In order to improve the existing system and to harvest newer opportunities in the hill agricultural system, a proper understanding of the composition of agri-horti-silvi-pastoral farming system and livestock based farming system is necessary. There is a considerable scope for development of agro-ecological zone specific farming along with horticultural interventions in the hill agriculture. At the same time there is an urgent need to give top priority to land use pattern, soil and water conservation and environmental sustainability. Agri tourism can be exploited in hill agriculture. What Hill agriculture needs is the appropriate technology, emerging markets, investment and risk cover.

The Agreement on Agriculture, the AoA, was negotiated to cover loopholes in the agriculture sections of the original GATT and was signed in April 1994 at Marrakesh, Morocco. Its first step was to get all countries to replace the various quota and other non-tariff restrictions on agricultural imports with equivalent-level tariffs; then countries would progressively cut those tariffs (by 36% over six years for developed countries, 24% over 10 years for developing countries). Restrictions were also mandated in other areas, such as export subsidies and in the AMS, the “aggregate measure of support”, which measured all the assistance going to a country’s farm sector. However, developing countries already had low levels of agricultural support, while developed countries had very high levels, meaning the field was still tilted in favour of the rich countries.

The WTO’s Agreement on Agriculture which came into effect on 1^st January 1995 brought world agriculture production and trade under multilateral trade rules. It was supposed to herald a new era of trade liberalization in the agriculture sector, as hitherto agriculture had been mainly exempted from the disciplines of GATT.

The adoption and use of a new technology causes disruptions in the sociocultural system of a nation and induces a change from established practices to distinctly different and complex forms of social practice. The deployment of ICT into the predominantly traditional societies of developing countries is therefore very disruptive. In view of this, a seamless integration of both the technical and socio-cultural systems of societies where technology transfer takes place is necessary for a thriving ICT deployment. Unfortunately, technological transfer to developing countries is driven by a perspective that is based on the development experience of Western industrialized nations.

It is indeed highly inspiring to see that in India, people are gradually getting aware of the multiple roles of Information Technology in the overall growth of the country. The bureaucrats and policy makers have equally emphasized the significance of exploring and exploiting the benefits of IT. Moreover, the governance has also realized that with availability of vital infrastructure Information and Communication Technologies can be used to improve the lives of the rural and underprivileged section of the Indian society, especially the ones living below the poverty line (BPL). Nonetheless, the Government will have to play the role of a catalyst in this huge integration project. A strategic framework including actors from Central & State Governments and Civil Society Organizations to capture the benefits of ICT and make it reach the countryside can do wonders in this regard.

Recent advances in information technology are making it more feasible to provide farmers with marketing information they need. However, farmers are still lagging behind in getting the information as accessibility to this technology is not available to them for various reasons. The major reason for this is abundance of small and marginal farmers without formal education and training in proper decision making. This problem is more acute for North Western (NW) hill farmers as besides above constraints, accessibility to information centers is very difficult due to undulating topography and lack of communication and transport facilities.

In the North-Western hill states, not many initiatives have so far been taken to use the information technology for the rural/agricultural development. Presently, use of radio and television for acquiring the information is limited as these media do not give focused information for different target areas. Even newspapers, in their local versions, do not provide regular updates for different major mandis regarding vegetables. This area has also been neglected by AGMARKNET (www.agmarknet.nic.in) for the market information regarding hill crops. For Himachal Pradesh and Uttaranchal, only one and three markets, respectively, has been covered. This shows the apathy of agricultural development departments towards incorporating ICT into the day-to-day activities of hill farmers.

In spite of development of irrigation and expansion in transportation and communication; the risk or we can say threat in agriculture sector such as its production and yield has increased in the country. The risk is much higher for farm income than production, as is evident from lower risk in area and higher risk in production. It has been reviewed from the state wise results of area and production which shows that only in the states where irrigation is very consistent; it helped in plummeting the risk and vice-versa. In some states farmers face twin problem of very low productivity accompanied by high risk of production. Also, with the course of time, neither technology nor any other measure helped in reducing production risk in all over the country. Therefore, there is strong need to plan and broaden insurance products or we can say insurance policies for agricultural crops and their production. No doubt various insurance schemes has been launched by the Government of India for covering various agricultural crops in the country as well as in the states but agriculture insurance has served very limited purpose. The coverage through insurance schemes in terms of area under crops, number of farmers and value of agricultural output obtained is very small and the payment of insurance based on area approach fail to notice affected farmers outside the compensated area, and most of the schemes are not workable. It has been viewed in most of the parts of the country. So there is a need to restructure the programme vigilantly to make it feasible and to increase its prospects for future expansion to impact more farmers. This whole process is in immediate need of rehabilitated efforts by Government of India as well as state governments in provisions of introducing new crop insurance policies with full financial support. The government should also extend support to private stakeholders for providing agricultural insurance which in turn will help in increasing insurance coverage and in improving viability of the insurance schemes over time. Moreover the crop insurance policies shouldbe simple in plan so that they are easily understood to the farmers. At last we can say that, good insurance products with good management are key for successful operation of an agriculture insurance scheme all over the India.

The financial system in India has grown rapidly in the last three decades and more. The functional and geographical coverage of the system is truly impressive. Nevertheless, data do show that there is exclusion and that poorer sections of the society have not been able to access adequately financial services from the organized financial system. There is an imperative need to modify the credit and financial services delivery system to achieve greater inclusion. The implementation of the recommendations made in this Report could go a long way to modify particularly the credit delivery system of the banks and other related institutions to meet the credit requirements of marginal and submarginal farmers in the rural areas in a fuller measure. However, creating an appropriate credit delivery system is only a necessary condition. This needs to be supplemented by efforts to improve the productivity of small and marginal farmers and other entrepreneurs so that the credit made available can be productively employed. While banks and other financial institutions can also take some efforts on their own to improve the absorptive capacity of the clients, it is equally important for Government at various levels to initiate actions to enhance the earnings capacity of the poorer sections of the society. The two together can bring about the desired change of greater inclusion quickly.

India is basically agriculture, which is the main source of livelihood for 70% of people. Livestock enterprise is not the exception. The primary sectors included the agricultural labourers, labours (workers) etc. The agriculture contributes about 40% of National income. And two problems in Agriculture are lack of Technology and Institutional arrangements. The investment is not possible an account of poor yielding resulting in pitiable economic conditions and. The establishment of NADARD with it objective in promoting health and strength of credits institutions forming front of the delivery system, i.e. COoperatives, Commercial Banks, RRBS is the Landmark in Agricultural Finance.

In recent years poverty elimination has become the most important development objective. Introduce the land reforms and laws for the hill areas as per the needs of the tribal people in keeping with the changing times. It is concerned on the social inequality between the advance majority sections of the society and the backward hill people, negligence relating to the roads and transport, health service, electricity, water supply, education, agriculture and sports. It shall strive to protect, safeguard and ensure proper management of the lands, forests and mineral resources of the hill people. As inequality in the distribution of production inputs, especially agricultural land seems to be the main cause of rural poverty and income disparity. A successful redistributive land reform may increase small household production and contribute directly and immediately to reduce poverty and economic inequality. Redistributive land reform has been an increasingly important strategy for both poverty alleviation and socio-economic development. The impetus for land reform is then the possibility of improved social justice and equity. An effective land reform program must boost efficiency and promote equity and so land ownership should be targeted towards those who use it most productively.

The significant marginal value of land of both consumption and income implies that an effective land reform policy could well be the most effective approach to alleviate hills poverty. The study investigates the effect of other complementary factors along with land on consumption and income. These all suggest that programmes of access to land must be packaged as elements of more comprehensive programmes in order to secure the poverty reduction potential of land. This study also analyses the economic relationship between access to land and poverty in hills area by establishing the link between land and consumption as well as land and income. The significant marginal value of land of both consumption and income implies that an effective land reform policy could well be the most effective approach to alleviate rural poverty. So in this paper we would like to trace the problems related with Land reforms in hills area, agriculture development and poverty alleviation. What are the major problems in Land reforms in Hills are and how to cope up with those problem.

Traditionally, agriculture in India was practiced on a subsistence basis; the villages were self sufficient, people exchanged their goods, and services within the village on a barter basis. But, with the development of means of transport, storage facilities and other infrastructure, agriculture has become commercial in character. The hills of India produces a wide range of goods starting from temperate fruits like apple to subtropical fruits like guava and cash crops like saffron, kala zeera, buckwheat etc. that are demanded at every corner of the country and even the world. The hills in India lacks infrastructure because of which farmers are not able to fetch a better price for their produce.

Agriculture is the dominant activity in the hill economy, which confronts multiple risks and uncertainty. The low yield of food and cash crops, fodder, fuel and other minor forest produce and their stagnant growth affected the agrarian economy and in particular the household food security. The scattered land holdings, traditional mode of production, low use of modern inputs and lack of market incentives are the primary causes of the poor performance of agriculture in J&K. Increase in Seed Replacement Rate (SRR) of major crops, Popularization of hybrids, Soil and Water conservation measures, and Public-private partnership are important aspects need to be considered for agriculture development in hilly areas of J&K. Strengthening of markets, Innovative marketing techniques and On-line trading can help in a big way for solving the problems of marketing in such areas.