eChapters

Introduction

Increasing fresh water demands for ever growing population and it has increased by 600% over the past 100 year (Wada, et. Al, 2016) the annual increment rate 1.8 % whereas the present growth rate is less, only 1 % but this figure may be optimistic. The global water demands will grow significantly over the next two decades in all three components as: Industry, domestic and agriculture (U.N, 2018) industry and domestic demand will grow faster than agriculture, but agriculture demands will remain largest (U.N, 2018). The global water demands for all purpose will increase 20% to 30% by 2050, up to 5,500 to 6,000 km3 per year (Burek et.al, 2016), whereas, agricultural demands will increase by 60% by 2025 (Alexandrators and Bruinsma, 2012).

Introduction

Agroforestry being old as an art and new in its scientific terms has been gaining importance in the modern era due to shift of world from technology to nature in search of resilient way of sustaining livelihood (Dutta et al., 2023, Sharma et al., 2023 Bishaw et al., 2022, Agnoletti et al., 2022). The simplicity of the agroforestry system is the flagship reason of its widespread applicability and reliability in agricultural domains. There has been change in the world perspective regarding the nature and natural resources in recent times. Although there has been forest over 31 per cent of the world’s total geographical area (FAO and UNEP, 2022) but the stabilization of ecosystem and sustainable development is difficult without subsequent interaction between the tree, crop and livestock component on farm lands, being collectively called as agroforestry.

Introduction

In recent decades, integrating trees with crops for food and wood production has received considerable attention in both tropical (Garrity et al., 2010) and temperate regions (Palma et al., 2007). The growing of trees in combination with the agricultural crop is a land management practice that farmers have been practicing since the ancient period. Seasonal agricultural/horticulture crops, woody perennial trees (multipurpose), and/or animals are major components of various agroforestry systems. According to Sanchez (1995), the science of agroforestry revolves around four aspects: competitiveness, complexity, sustainability, and profitability, and all of these factors must be balanced in order to produce beneficial outcomes. In fact, agroforestry is significantly assisting in meeting the United Nations Millennium Development Goals (MDGs) such as poverty and hunger eradication, improved health, nutrition, and education for people, gender equality, and environmental sustainability, particularly in developing countries (Garrity, 2004, 2006).

Introduction

`The living and nonliving components of ecosystems, as well as the conditions and processes that occur within them, create services thus connecting ecosystems and human cultures. The preservation of Earth’s biological diversity and the protection of the benefits, or “ecosystem services,” those functioning ecosystems bring to humanity are two primary goals of environmental conservation. Agroforestry is increasingly viewed as providing ecological services, environmental advantages, and economic gains as part of a multifunctional working landscape. The multifunctional importance of agroecosystems was emphasized in both the Millennium Ecosystem Assessment (MES 2005) and the International Assessment of Agricultural Science and Technology for Development (2008).

Introduction

More than a third is covered by drylands in the terrestrial land surface, which have a harsh and vulnerable natural condition (Maier et al., 2014). Due to insufficient water availability, dry areas have a scant population of vascular plants, as well as poor availability of the nutrient turnover with poor availability of the resources as a result of severe temperatures (Adeel, 2008). Biological soil crusts or Biocrusts commonly protects the soil surface in dry environments and it is considered “ecosystem engineers” of arid and semiarid areas, as well as signs of ecosystem health (Briggs and Morgan, 2011; Bowker et al., 2008). They are connected in dryland ecosystem restoration level or degradation (Assouline et al., 2015). When compared to chemical or physical crusts, biocrust is the largest word that explicitly implies that these are the crusts which are dependent on the living organisms’ activity.

Introduction

According to the Forest Survey of India (FSI) “all lands, more than one hectare in area, with a tree canopy density of more than 10% is defined as Forest” (FSI 2009). The status of forests and forest management systems contribute to the vulnerability of forests to climate change. Indian forests are extremely diverse and heterogeneous. Forests and Climate Change are intimately intertwined. Forests have regulated the climate, rain, groundwater, soil of the earth over millennia. Their transpiration act as a regulator of the balance of oxygen and carbon-di-oxide: the world’s forests and forest soils currently store more than one trillion tons of carbon – twice the amount found floating free in the atmosphere. The forest and soils are home of biological diversity.

Introduction

Future agricultural production potential is in danger due to the existing cropping system, characterized by irresponsible chemical utilization, extensive tillage, monoculture, and soil health degradation. Consequently, a significant challenge for modern agriculture lies in ensuring adequate nourishment for the entire world’s population while also safeguarding the environment. The intensification of agricultural practices negatively impacts vital natural resources like soil, water, air, and biodiversity throughout various developmental stages. While the conventional cropping system have enhanced crop productivity, its consequences including land degradation, resource depletion, reduced organic matter insoil, draught, soil salinity, erosion, and climate change pose significant global threats (Tomar et al. 2014; Yadav et al. 2014; Mandal et al. 2020; Rani et al. 2021).

Introduction

Soil is a vital, complex, and firm layer of the land surface that provides a source of minerals and organic matter interacting with air and water to harbor life forms. (Lobmann et al., 2022). Versatile micro and macro living organisms, i.e., bacteria, fungi, and actinomycetes, inhabit soil and contribute to its quality, health, and inevitable role in serving the environment (Elsakhawy et al., 2022). Soil roots for a variety of crucial functions which involve ecosystem services or socioeconomic activities, e.g., biomass production, climate gas fluxes of CO2 , N2 O, and CH4 , water cleaning, storage and supply, foundation of construction and provision of construction materials, or provision of habitats etc. The responsibility of soil in sustaining life on earth by providing and conserving resources is not negotiable.

Introduction

By enhancing microbial populations, enzyme activity, soil respiration, and microbial biomass, nano-black carbon is a novel method for the enhancement of soil biological characteristics. By reducing soil acidity and boosting soil fertility, nano-black carbon is believed to improve plant development. The application of nano-black carbon to agricultural soils can have a significant positive impact on plant productivity. In addition to potentially boosting soil resilience to climate change, nano-black carbon greatly boosted enzyme activity, microbial activity, and soil organic carbon retention.Due to a liming action, nano-black carbon has been proposed as a potential biotechnology to boost agricultural yields in acidic soils.

Introduction

Overview of the Chapter’s Focus on Agroecology and Soil Sustainability

The ecology and biodiversity of our globe are being threatened by human activity, notably unsustainable agriculture methods. This chapter explores the vital function of agroecology, the intersection of ecological and agricultural concepts, in promoting sustainable farming systems. Soil sustainability, essential for effective and resilient agrarian operations, is critical to this strategy. Here, we give an overview of these key terms and talk about the pressing need to switch to sustainable agriculture methods to preserve the  health of the soil, increase food security, and create adaptable environments.

Introduction

More than three billion people are at risk of poverty due to land degradation caused by humans (Kansanga, Kerr, Lupafya, Dakishoni, & Luginaah, 2021). The implementation of Soil Sustainability Management (SSM) practices remains low among smallholder farmers, despite the fact that SSM has developed as a generally accepted technique to tackling soil degradation in Agro ecosystems (Kansanga et al., 2021). When it comes to food, water, energy, climate, biodiversity, and the provision of ecosystem services, soil plays a pivotal role in addressing these global environmental sustainability concerns (McBratney, Field, & Koch, 2014). The availability of food, fiber, clean water, and a varied landscape are all dependent on healthy soil.

Introduction

Soil plays a vital role in fulfilling fundamental human requirements, such as the provision of sustenance and water, while also serving as the primary medium for supporting biodiversity. The sustainability of soil in the 21st century is dependent upon not only the implementation of effective management practices by farmers, foresters, and land-planners, but also on government regulations, policies, marketing strategies, and subsidies (Mishra et al., 2017). The increasing influence of human activities on the Earth’s natural environment has led to significant global challenges concerning the interplay of planetary and public health (J. Huang et al., 2018).

Introduction

Waste management and soil sustainability are two critical aspects of environmental conservation and sustainable development. As our global population continues to grow and consume resources at unprecedented rates, it becomes increasingly important to manage waste effectively and preserve our soil health and productivity. Anthropogenic activities have consistently produced waste. The World Bank predicts that worldwide garbage production will rise to 70% by 2050 if no substantial actions are taken (Ghosh, 2020). This was not a significant problem when the world’s population was small; however, it is acquired as a major concern with industrialization and urbanization revolution. Lack of proper waste management has caused pollution of water, land, and atmosphere, as well as a significant effect on human health (Raza et al., 2022a; Raza et al., 2022b).

Introduction to Soil Restoration and Management

One of the most crucial elements for human survival is the availability of arable land. Desertification caused by land degradation has emerged as a serious global environmental threat to human well-being and sustainable development in recent years because of both climatic shifts and an increase in human activities that have direct impacts on soil. It has been widely alarmed by the United Nations Convention to combat desertification and has shown considerable interest in this issue (UNCCD, 2015). Soil degradation is used to describe the transformation of arable land into unproductive land because of natural processes, typically accelerated by human activity (Lal, 1993).

Introduction

Organic farming is a comprehensive approach to production management that promotes and improves Agro-health, ecosystems including biodiversity, biological cycles, and soil biological activity. It prioritizes management approaches above off-farm inputs, and agronomic, biological, and mechanical farming procedures are used rather than synthetic resources (Ajibade, Ayinde, and Abdoulaye 2020). The term “organic farming” refers to a production technique that excludes the use of artificially formulated fertilizers, pesticides, or growth regulators for agronomic practices or the use of different chemicals for livestock production, i.e., feed additives, growth promoters and antibiotics, etc. (M. Singh 2021).

Introduction

Global population growth has led to an increase in demand for energy, food, and other essentials, resulting in an increase in agricultural land. Poor farming techniques, urbanization, and a lack of soil management measures have negative consequences for agricultural soils, such as reduced soil fertility, migration of soil organisms, and loss of soil microbiota and ultimately loss of soil health(Mehmood et al., 2020; Omotayo and Babalola, 2021; Syed et al., 2022). In addition, fertilizers used in agriculture have an impact on soil quality and health. Soil fertility is defined as the ability of a soil to meet the physico-chemical and biological requirements of a plant for growth, reproduction and quality, taking into account plant and soil type, land use and climatic conditions (Abbott and Murphy, 2007; Tyagi et al., 2019).

Introduction

Agriculture contributes a vital part within the financial stability of smallest emerging nations such as Pakistan as well. The economic system of Pakistan is fundamentally based upon agriculture (Govt. of Pakistan, 2004-2005). The total surface of Pakistan approximately 796,095 km2, of which 8.3 million km2 are uncultivated and 22 million km2 are farmed (Govt. of Pakistan 2015 2016). Despite an average yearly increase of 2.7%, agriculture contributes 21% of Pakistan’s GDP (Govt of Pakistan, 2004–2005). Farming is a sector whose fundamental and commercial models combine. Agriculture’s importance to the economy may be examined through three distinct perspectives: 1) as a source of nutritious food for the country and raw materials for internal industry; 2) as a way to generate currency from abroad and 3) as a source of products and services for local industries and the global market (Govt. of Pakistan, 2015-16).

Introduction

Soil is a non-renewable resource that sustains life, providing ecosystem services such as biomass production, contaminants filtration, raw material supply, nutrient, and hydrological cycle (Panagos et al., 2020). It contributes about 95% to global food production (Borrelli et al., 2020). Soil is a major global biodiversity pool and a large carbon pool on Earth. Therefore, it plays a crucial role in regulating energy and mass flow and their transfer between the biosphere, lithosphere, hydrosphere, and atmosphere (Ferreira et al., 2021). Climate change and unsustainable management practices are threatening the soil’s natural capital resulting in soil degradation occurring simply from erosion to contamination and leading the soil to completely unproductiveness under severe conditions, leading to food insecurity (Ashoka et al., 2017; Syed et al., 2022)

Climate change refers to long-term shifts in temperatures and weather patterns. These shifts may be natural, such as through variations in the solar cycle. But since the 1800s, human activities have been the main driver of climate change, primarily due to burning fossil fuels like coal, oil and gas. (https://www.un.org/ en/climatechange/what-is-climate-change) While it is possible to achieve enhanced food production to meet the demands of growing populations, the prevailing negative environmental trends, if continued, might cause crises in many parts of the world (Molden, 2007). The effects of climate change on agriculture can take place through changes in average temperatures, rainfall, and climate extremes (e.g., heat waves); changes in pests and diseases; changes in atmospheric carbon dioxide and ground-level ozone concentrations; changes in the nutritional quality of some foods; and changes in sea level. (Anonymous, 2014A)

The capacity of soil to function as a vital living system, within ecosystem and land use boundaries, to sustain plant and animal production, maintain or 

enhance water and air quality, and promote plant and animal health (Doran and

Zeiss, 2000). A healthy soil may function is as follows:

• Sustain biological activity, diversity, and productivity

• Regulate, store of nutrients and cycle water and, decompose organic

matter

• Filtering and buffering, degrading, mineralizing, immobilizing, and

detoxifying organic and inorganic materials

• Inactivate toxic compounds, suppress pathogens, protect water quality,

and enhance catchment soil health.

Introduction

Climate change is threatening food security globally. Countries like India are more vulnerable in view of the tropical monsoon climate and poor coping capacity of the small and marginal farmers. Several agricultural practices like indiscriminate use of agro-chemicals and crop residue burning contribute to emission of greenhouse gasses leading to warming of the atmosphere. Sequestration of carbon both in the vegetation and soil is the most effective means of mitigating GHG emissions. There are several strategies of soil carbon sequestration which can be adopted at farm level. These include: conservation agriculture, biomass recycling, crop rotations and use of organic amendments. One of the recent developments is the conversion of crop residue biomass into biochar and using the char as a soil amendment rather than directly using the crop residues. Several studies show that biochar has a long life in soil and is more effective in sequestering carbon besides improving other soil properties like water holding capacity and nutrient availability. In Indian conditions, there is an immense scope for converting millions of tonnes of crop residues which are not used as fodder into biochar and use the same for enriching soil carbon.

Introduction

Productivity has increased as a result of the significant industrialization that has occurred in India during the past 40 years. However, it has also had detrimental effects on the ecology, particularly in India where soil contamination is progressively becoming more severe. In addition to the effects of man and land use, soil is constantly adapting changes in environmental conditions. A characteristic of soil pollution is the decrease in soil productivity brought on by the presence of soil pollutants. Some changes in the soil will be temporary and reversible, while others will be permanent. Pollutants in the soil have a negative impact on the physical, chemical, and biological characteristics of the soil and decrease its production. Soil pollution is a result of a variety of factors, including pesticides, fertilizers, organic manure, chemicals, radioactive waste, abandoned food, clothing, leather goods, plastics, paper, bottles, tins, and corpses. Industrial waste contains chemicals including iron, lead, mercury, copper, zinc, cadmium, aluminum, cyanides, acids, and alkalis, among others, which either directly or indirectly enter the soil.

Introduction

Soil organic matter is an indispensible component of soil health management. It plays an important role in improving soil physical, chemical and biological environment. Soil health refers to the capacity of the soil in terms of physical, chemical and biological properties for maintaining ecosystem services. With respect to agricultural lands, soil health implies the capability of the soil towards improving crop growth and yield, while also supporting environmental sustainability. Some important determining properties of soil health maintenance are soil reaction, salinity or alkalinity, soil organic matter, soil texture, soil structure/aggregation, water holding capacity, porosity, internal drainage, and nutrient retention capacity. Simultaneously, the key properties maneuvering soil health are soil aeration, internal drainage, nutrient cycling, susceptibility to erosion etc. Except some of the basic properties (soil texture) and processes (soil erosion), most of the determinant properties and processes are maneuvered by the presence of soil organic matter. A healthy soil must have strong resistance to degradation processes and able to recover following a perturbation because of inherent resilience (Magdoff 2001).

Introduction

Rice straw is produced as a by-product of rice production at harvest. Agricultural Waste Burning (AWB) is a major contributor of air pollution in many countries, particularly in South Asia. Exposure to fine particulate matter less than 2.5 μm (micrometer), also known as PM 2.5, released by AWB can cause premature mortality due to respiratory and cardiovascular diseases (Brauer et al.,2012). Combine Harvesters used on the spring rice crop leave behind stubble and straw on the field (Sidhu et al., 2007). Farmers burn the rice residue while preparing the field for wheat sowing season that follows. Further, migrant labour from neighbouring states of Bihar and Uttar Pradesh has decreased (Sirhindi, 2019), and resulted in an increase in the cost of agricultural labour during the rice harvest season (Sharma,2018). Farmers find it both convenient and economical to burn residue to clear and prepare their fields for the next crop. In 2018, over 20 million metric tons of rice residue was generated in Punjab, of which almost 10 million metric tons was subject to open-air burning (MoA, 2019). The time window between rice harvesting and wheat sowing is just 20 to 30 days towards the conclusion of the Kharif season, which is one of the primary reasons of crop waste burning (Balwinder et al., 2016).

Introduction

Microbial diversity is one of the main factors characterizing natural ecosystems; soil is considered one of the best storehouses of useful microorganisms in the world. Although the role of most of these microorganisms is still unknown, scientific progress is providing a better comprehension of the specific ecological functions of soil microorganisms (Ahmad, I.et al., 2008). Microorganisms in the rhizosphere soil play a key role in maintaining the soil fertility (Yadav et al. 2015), which is key for successful natural crop production to meet the increasing global organic food demand. Soil acts as a reservoir of air, water, and nutrients that is essential for plant growth. Only a few grams of soil contain hundred million to billion microorganisms. Bacteria are the most abundant microbes in soil followed by fungi; however, the actinomycetes are ranges in between bacteria and fungi. Other microbes that are found in smaller numbers are algae, cyanobacteria, protozoa, and nematodes. Soil gives the necessary support for anchorage to plant roots (Yadav et al. 2012; Bhaduri et al. 2015).

Introduction

Ideal plant health and productivity of a cropping system depends on an adequate amount of plant nutrients. Fertility of the soil refers to its capacity to support the production of crops. A productive fertile soil can support optimal plant growth, seed germination to plant maturity by providing adequate soil volume for plant root development, essential plant nutrients to meet the nutritional requirements of the plants, and encourage for the consequent plant structure. These attributes of the soil can be distinguished as inherent or dynamic soil quality indicators.Optimum plant health and productivity of a cropping system depends on an adequate supply of plant nutrients. The quantity of nutrients required by plants varies depending on many interacting factors including:

• Agronomic effects

• Soil properties

• Climatic condition

• Management practices

Nitrogen

Most commonly, complex organic compounds, ammonia, molecular nitrogen, nitrite, and nitrate are the forms of nitrogen found in soils. The physical and chemical conditions of the soil control the majority of the microbiological interconversions that change nitrogen.

Ammonia build-up, ammonia loss by volatilization, denitrification, nitrogen f ixation, and leaching losses of nitrogen are the primary changes that occur in submerged soils. The nutrition of rice is significantly impacted by these changes. Given the favourable circumstances for quick soil transformations and nitrogen loss, it is obvious that rice soils are nitrogen deficient.

Introduction

At a present time, Organic farming has an important priority in different areas due to worldwide in look of the growing need for pure and nutritious agriculture food and keep up the feasible and environmental pollution on long time associated with indiscriminate use of chemical fertilizer. The use of synthetic inputs in crop cultivation is necessary to meet the growing need for agriculture food in world. The natural fertilizers are made containing living or veiled cells or their strains of N2 fixation, P2 O5 solubilization bacteria. The biofertilizers are used for seed cramming, soil or vermicomposting region with the objective of rising quantity of such microbes and further those microbial processes which augment the obtainability of nutrients that can be easily digest by plants. Biofertilizers are playing higher role in increase soil productivity by f ixing atmospheric nitrogen, both, in relationship with plant roots and without it, solubilise and insoluble soil phosphorus and produces many plant growth substances in the soil.

Introduction

Manures are obtained from the plant residues, green manure, compost and animal wastes that are used as source of plant nutrients. They release nutrients after their decomposition. They essentially function as sustenance to the crops. They help in the proper cultivation of crops. The addition of manure enables the soil to hold more water. Organic manures have acids that dissolve the nutrients in the soil and make them available to the plants. manures can be grouped into bulky organic manures and concentrated organic manures. Brief dissection about manure given blow flow chart.

Bulky Organic Manure

Bulky organic manures are those materials of plant and animal origin, which contain small percentage of nutrients when added to the soil have tendency to decrease bulk density and to increase soil volume, thus providing better physical conditions for plant growth especially in coarse textured soils and also provide essential nutrients in smaller quantities than the chemical fertilizers. Characteristics of bulky organic manures:

Introduction

Problem soils are those that impede agricultural productivity owing to mineral stress, dryness, acidity, sodicity, waterlogging, etc. Vertisol, acid sulphate soils, saline-sodic soils, peat soil, and fine textured alluvial soils were the categories Beek et al., (1980) used to group the problematic soils. In addition to vast areas where deficiencies of zinc, phosphate, and iron, or excesses of iron, aluminium, and manganese limit rice yields, Ikehashi and Ponnamperuma (1978) observed that approximately 100 million hectares of land that are physiographical and climatically suitable for rice lie idle due to the soil toxicities caused by salt, alkali, acid, or organic matter. Problem soils can be broadly defined as those that have unfavourable conditions whether natural or artificially created that severely restrict the successful development of crops. Soil profiles with high groundwater levels and a less permeable argillic layer, degraded soils, sandy soils with low fertility, coastal soils that frequently flood, and laterites could all be categorised as problem soils. Without taking into account related soil functions, soil health is evaluated independently. It is also based on the f indings from a few soil tests for different criteria. 2015 has been recognized the International Year of Soils by the 68th UN General Assembly in recognition of the importance of soil health in all dimensions.

Introduction

 Salinity is a form of salt that occurs naturally within soils or water. When soil

becoming salty form that is called salinization, it can be caused by mineral

weathering called as natural process but it can be caused by irrigation called

as artificial process. Saline or salty soil have a high salt content like sodium

chloride (NaCl also called table salt). Salinity is like- abiotic stress for plants

and reduced the plant growth but not for all because some of them crops are

survive in better way for growth and development such as barley, sugerbeet,

cotton and mustard etc. Basically, stress are two types-biotic and abiotic

stress. Abiotic stress are also called nonliving stress like- drought, salinity,

submergence, heat, cold and temperature that are affect to plant life cycle so

that are called as abiotic stress. Natural water and all types of soil both contain

soluble salts. Amount of salt affected to weather of soil, when excessive salt

present in soil and it adversely affects to crop growth and developments. Salt

affected soils exist under arid and semi-arid climates. Major constitutions of

soluble salt in soil are the cations and anions. Cations are containing sodium,

calcium, magnesium and anions are contains chloride, sulphate, carbonate and

bicarbonate. Saline soil have <8.5 pH, >4EC (dS/m) and <15 ESP. where EC

is eclectical conductivity that is measure of soil salinity and ESP stand for

Exchangeable sodium percentage.

Soil pH

 Soil reaction is measured by pH (Puissance de Hydrogen) of a suspension of

soil in water. The word “pH” has originated from the French word “pouvoir

hydrogen” which means powers of hydrogen. The acidity, neutrality or

alkalinity of a soil is measured in terms of hydrogen ion activity (active

concentration) of the soil water system. Most of the agricultural soils have

a pH varying from 4.5 to 8.5. The active concentration of hydrogen ion is

termed as ‘active acidity’ which is 1/50,000 or 1/1,00,000 times lesser than the

exchange acidity or exchangeable hydrogen.

 Soil pH is a measure of the activity of ionised H (H+) in the soil solution. The

pH of a solution can be defined as the negative logarithm to base 10 of the H+

ion activity or the logarithm of the reciprocal of the H+ ion activity.

pH = -log10

 a[H

 +] = log10

 1/[H

 +]

 There is difference between activity and concentration. Activity and

concentration are related by the mathematical expression

 a

 c

 F

 = where a = activity of a species (moles L-1)

 c = concentration of that species (moles L-1), f = activity coefficient

 a = c for dilute solutions, f = 1

 Activity coefficient of an ionic species is the degrees of freedom of that species

to participate in an equilibrium reaction or to maintain its charge under an

ionic environment.

Introduction

 India, situated between the latitude of 08004’ and 37006’ N and longitudes of

68007’ to 97025’ E, has a geographical area of 329 Mha. Physiographically, it

can be divided into three broad regions, viz., Peninsula (a triangular Plateau in

the Deccan and South of the Vindhyas), Mountain region of the Himalalayas

(Extra-Penninsula), and the Indo-Gangetic Plain separating these two regions.

Geologically, a great part of the Penninsula is occupied by the gneiss, schists

and other rocks of diverse nature. Red soils (Alfisols) generally predominate in

this region. The western and central parts predominate in basaltic rock having

Black cotton soils of different thickness (Vertisols, Inceptisols). The mountain

region shows the development of marine sediments of all ages, especially, in

north of the Himalayas. The vast Indo-Gangetic and other plains of Pleistocene

origin are composed of alluvium of the great river systems flowing in this

region. The alluvial soils of this region depend on the age of alluvia and degree

of development.

Climatically, India shows three distinct seasons:

 i) Cool and mainly dry winters from November to February

ii) Hot and mainly dry summers from March to June

iii) Monsoon rainy season from mid-June to September.

Introduction

Soil resource catalogue provides an insight into the capability and the constraint

of mapped area for its optimum exploitation towards developmental planning.

For this motive soil survey series as an essential tool. Soil survey is essentially

a study and mapping of soils in their natural environments and systematic

examination, description, classification and mapping of soil of area.Soil survey

contains a group of compound operation involving

•             To study important properties of soils and associated land features.

 •            Define taxonomic units through correlation and classifications of soils.

•             To establish and draw a border of different kinds of soils on standard

topographical base map through mapping of soils.

 •            Transfer of technology from research farm to farmer ‘s field under

different soil condition and management practices.

Cation Exchange of Clay Minerals in Soil

The term “clay mineral” refers to phyllosilicate minerals and to minerals which impart plasticity to clay and which harden upon drying or firing. Clay minerals are layer silicates that are formed usually as products of chemical weathering of other silicate minerals at the earth’s surface. Clay minerals in soil play a significant role in exchanging cations, which are positively charged ions, and in regulating soil fertility and nutrient availability. Cation exchange capacity (CEC) is a measure of a soil’s ability to exchange cations and is influenced by the type, abundance, and charge properties of clay minerals in the soil. Clay minerals have a high CEC due to the presence of charged surfaces (silanol and alumoxane groups) that can exchange cations with the soil solution. The most common cations exchanged by clay minerals are hydrogen (H+), calcium (Ca2+), magnesium (Mg2+), potassium (K+), and sodium (Na+). When a soil solution comes into contact with clay minerals, cations in the soil solution are adsorbed or attracted to the charged surfaces of the clay particles.

Introduction

Soil aeration status involves the rate of such ventilation, as well as the proportion of pore space filled with air, The composition of that soil air and the resulting chemical oxidation or reduction potential in the soil environment. Water provides the base for food, nutritional and environmental security. Soil water plays a significant role in controlling the energy balance of the soil and its overlying micro-environment by modifying its radiation exchanges and thermal properties. Soil temperatures affect plant and microorganism growth and also influence soil drying by evaporation. It is a central maximum of ecology that “everything is connected to everything else.” This interconnectedness is one reason why soils are such fascinating and challenging objects of study. In this chapter we shall explore three aspects of the soil air, water and temperature.

Introduction

The interest in soil as a natural body originated from its ability to produce and sustain crops. The scientific study of soil probably started in the mid-nineteenth century and was dominated by geologists, chemists and plant physiologists. Justus von Liebig (1840) in his famous publication, Chemistry Applied to Agriculture and Physiology, put forward the theory that plants assimilate mineral nutrients from soils which varied in their capacity of nutrient supply. The ‘Law of Restitution’ propounded by him states that whatever is being taken by plants from the soil needs to be restored to maintain the nutrient supplying capacity of the soil.

About two-thirds of the developing world’s three billion rural people live in about 475 million small farm households, working on land plots smaller than two hectares. Many are poor and food insecure and have limited access to markets and services. Their choices are constrained, but they cultivate their land and produce food for a substantial proportion of the world’s population. Besides farming, they have multiple economic activities, often in the informal economy, to contribute towards their small incomes. These small farms depend predominantly on family labour. In China, nearly 98 percent of farmers cultivate farms smaller than 2 hectares – the country alone accounts for almost half the world’s small farms. In India about 80 to 85 percent of farmers are small. In Ethiopia and Egypt, farms smaller than 2 hectares constitute nearly 90 percent of the total number of farms. In Mexico, 50 percent of the farmers are small; in Brazil smallholders make up for 20 percent of the total number of farmers (Rapsomanikis, 2019).

Biodiversity encompasses the different kinds of life we find in one area— the variety of animals, plants, fungi, and even microorganisms like bacteria that make up our natural world. Each of these species and organisms work together in ecosystems, like an intricate web, to maintain balance and support life. Biodiversity refers to all species and living things on Earth or in a specific ecosystem. Biodiversity brings together the different species and forms of life (animal, plant, entomological and other) and their variability, that is to say, their dynamics of evolution in their ecosystems. Traditionally, there are three levels of biodiversity: genetic diversity, species diversity, and ecosystem diversity. But what does each of these levels really mean.

Stress is an intrinsic part of biological systems, and successfully adapting to stimuli that induce stress is essential for the survival of dryland crops and farm animals kept in a complex and ever-changing environment. Here the biotic stresses of crop plants are treated and not that of farm animals to avoid the expansion of the volume of the chapter. Biotic stress in plants is caused by living organisms, specifically viruses, bacteria, fungi, nematodes, insects, arachnids, and weeds. In contrast to abiotic stress caused by environmental factors such as drought and heat. Biotic stress agents directly deprive their host of its nutrients leading to reduced plant vigour and, in extreme cases, death of the host plant. In agriculture, biotic stress is a major cause of pre- and postharvest losses. Plants respond to biotic stress through a defence system (Atkinson and Urwin, 2012).

Marginal and sub marginal lands are being brought under cultivation to meet the demand of human and livestock in terms of rising demand of 6F viz., food, fodder, fuel wood, fibre and fertilizer. These in lands are unable to sustain productivity. Cultivation on such lands leads to imbalance in the ecosystem. In order to meet the above said demands and to conserve the natural resources, a diversified land use system needs to be adopted in different agro-ecological regions of the country as an alternative to conventional cropping systems. Through this approach, the biological productivity and quality of resource base of degraded lands can be significantly enhanced. Land use systems which are alternatives to crop production are called by the term ‘Alternate Land Use Systems’.

Dryland agriculture is a more vulnerable system in view of its high dependency on monsoon rains which are of aberrant nature. The risk of crop failure and poor yields always restrain farmers from investing on new technologies and input use.

Concept of resilience

Resilience is used to describe the magnitude of a disturbance that a system can withstand without crossing threshold into a new structure or dynamic. Resilience is defined as “the ability of a system and its component parts to anticipate, absorb, accommodate, or escape from unacceptable standards of living due to the effects of a hazardous event, in a timely and efficient manner”. In other words, resilience describes the capacity of communities in a given context or landscape to maintain and improve their livelihoods—despite stresses and shocks—through the sustainable management of natural resources while maintaining key ecological functions

In India since ages, the dryland farmers adopted a kind of mixed farming involving traditional annual crops and livestock consisting of one or two cows / bullocks and few poultry birds. This traditional system though of small scale provided some kind of risk minimisation particularly in the years of scanty rainfall causing agricultural drought. (https://coabnau.in/uploads/1587050523_ Agriculturalheritage.pdf) Discouraged by their marginal impact on farm economy, dryland farmers switched over to the lure of ‘productive’ mono-cropping with certain commercial crops like cotton etc. The continuous mono-cropping resulted in impoverishment of soils and low crop yields which took farmers into the labyrinth of poverty.

Historical perspective: Planting of single crops or mono-cultural agriculture—is a recent invention of the industrial agricultural complex (Hirst, 2019). While unequivocal archaeological evidence is difficult to come by, it’s believed that most agricultural field systems in the past involved some form of mixed cropping. That’s because of even botanical evidence of plant residues such as starches or phytoliths of multiple crops are discovered in an ancient fields (Hirst, 2019). Mixed cropping, also known as polyculture, or co-cultivation, is a type of agriculture that involves planting two or more crop plants simultaneously in the same field so that they grow together. The primary reason for prehistoric multi or mixed cropping probably had more to do with the needs of the farmer’s family and perhaps to avoid crop failure. It’s possible that certain plants adapted to multi-cropping over time disappeared as a result of the domestication process (Hirst 2016).

Dryland agriculture limits the crop growth to a part of the year due to lack of sufficient moisture (Peterson et al., 2006). According to the Fourth five-year plan of India, dry lands are defined as areas which receive rainfall ranging from 375 mm to 1125 mm and with very limited irrigation facilities. Dry lands are economically fragile regions which are highly vulnerable to environmental stress and shocks. Degraded soils with low water holding capacities along with multiple nutrient deficiencies and depleting ground water table contribute to low crop yields and further leading to land degradation. In a country like India, 44 per cent of the total food production is supported by dryland agriculture, thereby playing a critical role in nation’s food security. With the increasing population, food production has to be increased. A real need to second green revolution has been envisioned, which can be achieved by improving the dryland agriculture.

Rainfed farming has a distinct place in the Indian agriculture, occupying 67 % of cultivated area contributing 44 % of food grains to our national food basket, supporting 40% of human and 65% of livestock population. The system is characterized by resource poor farmers, poor infrastructure and low investment in technology inputs. Even when full irrigation potential of the country is realized, 50% of the net sown area is continued to be rainfed. The important problems encountered in rainfed areas are unfavorable weather, limited choice of crops and varieties, low cropping intensity and unstable productivity. The research work done by the net work of AICRPDA (All India Co-ordinate Research Project for Dryland areas) centres and SAUs (State Agricultutal Universities) indicated that the production in rainfed environment could be enhanced by 200 % compared to the productivity of farmers’ field by adopting improved cropping systems and agro techniques.

Soil and water are the basic resources in drylands. Soil supports plant life by providing a medium for their growth and development. It is a non-renewable natural resource and susceptible to rapid degradation through various forms of erosion processes. Worldwide, around 52% of total productive land has been degraded by various kinds of degradation processes and almost 80% of the terrestrial land is affected by water erosion .Further, annually ~10 million hectares (Mha) of cropland becomes an unproductive at the global level due to soil erosion with an average rate of 30 t ha−1 year−1 soil erosion .In India, out of 328 million hectares of geographical area, 68 million hectares are critically degraded while 107 million hectares are severely eroded. Soil degradation in India is estimated to be occurring on 147 million hectares (Mha) of land, including 94 Mha from water erosion, 16 Mha from acidification, 14 Mha from flooding, 9 Mha from wind erosion, 6 Mha from salinity, and 7 Mha from a combination of factors (Battacharya et al., 2015).

Moisture deficit causing shortfalls in crop production is the characteristic feature of dryland agriculture. Other adverse factors viz., decline in soil fertility together with play of biotic stresses add to the complexities of dryland crop production. Added to the proven agronomic management to combat the problem of drought in dryland agriculture, there is the need to tailoring of suitable crop varieties which can yield reasonably well under conditions of moisture deficit (Varshney et al., 2021). In this context, the appropriate developmental rhythm along with the combination of the constellation of characters of the crop plant matching with the rainfall and the soil moisture availability patterns of the zone are the important considerations together with stability of yield (Hanson and Nelsen, 1980). This task being a complex one, the problem should be approached through multidisciplinary strategy that should buffer the genetic and breeding efforts.

The world’s drylands include hyper-arid, arid, semi-arid and dry sub-humid areas where rainfall is highly scanty and variable. Droughts are common in areas / zones where water is the principal limiting factor for agriculture (https:// www.fao.org/3/t0122e/t0122e03.htm) . Dryland soils are characterized by low levels of moisture, organic matter, and biological activity, consequently such soils are very poor in fertility devoid of plant nutrients. When, these soils suffer further degradation in fertility, resulting in erosion, desertification, and salinization when crops are grown on such soils inappropriately without any scientific basis. However, the major factor limiting agricultural production on drylands is the lack of adequate moisture for crop growth or drought.

Among the various natural resources upon which all living organisms depend, soil is the unique because of its non-renewable in nature, heterogeneity in space and time and susceptibility to degradation inflicted by biotic as well as abiotic agents. Whereas, escalating population demands, in one way, to bring more land under the plough for providing food, fodder, fuel and fibre, simultaneously, on the other way, these finite natural resources are dwindling by leaps and bound, through overexploitations and mismanagement, the combined effect of which leads to land degradation, a serious global threat and major environmental issues in the present times.