eChapters

Structure of Crystalline Clays

Soil clay minerals are of two types: crystalline and amorphous. Crystalline clays are made up of sheets of octahedra and tetrahedra of O and OH. Clays with alternating sheets of aluminium octahedra and silicon tetrahedra, are called, “1:1 clays” or “diphormic clays”. A sheet of octahedra is sandwiched between two sheets of tetrahedra in 2:1 clays which are called as, “triphormic clays”.

The building blocks of clay crystals are called “unit cells”. The geometry of octahedra has 3 voids in each half unit cell, equivalent to 6 negative valences. In order to nullify these 6 negative valences, 6 positive valences are needed. The 6 negative valences can be nullified by 3 divalent cations, one each in the three voids, or by 2 trivalent cations, leaving the third void empty. When trivalent cations such as Fe³+ and Al³+ fill two of the three voids, the clays are called, “dioctahedral clays”. When three divalent cations such as Fe , Mg and Mn fill up all the three voids, such clays are called, “trioctahedral clays”.

Indian Government has several developmental programmes to promote agriculture and rural sector. It includes Drought Prone Area Program, Antodaya Programme, Integrated Rural Development Programme, Hill Area Development Programme, Desert Development Programme, Intensive Jawahar Rojgar Yojna and Employment Assurance Scheme, Indira AwaasYojna, Integrated Waste Land Development Programme, National Food Security Mission, National Horticulture Mission, etc. Mahatma Gandhi National Rural Employment Guarantee Scheme (MGNREGS) has the main focus to provide guaranteed employment for 100 days in a year to every rural household. Since 2014, the Swachh Bharat Abhiyan has been a major initiative by the Government of India.

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)

Introduction
 
Climate change is a result from emission of greenhouse gases (e.g. CO₂, CH₄, N₂O, etc.) that will cause atmospheric warming (IPCC, 2007). Climate change may be due to natural internal processes or external forcing such as modulations of the solar cycles, volcanic eruptions, and persistent anthropogenic changes in the composition of the atmosphere or in land use. Human induced changes in atmosphere composition are a major concern. Burning of fossil fuels, like oil, coal, and natural gas is adding CO₂ to the atmosphere.

GHG emissions as an Agriculture
Agriculture is significant source of GHG emission. Farming records for roughly 10-12 % of absolute anthropogenic GHG emissions, contributing 40 % of all out methane (CH4) and 60 % of nitrous oxide (N2O); agriculture is greatest wellspring of anthropogenic non-CO2 discharges. CH4 begins predominantly from metabolic action of methane-creating microscopic organisms in rice paddy soils and the gastrointestinal maturation of ruminants. N2O discharges get predominantly from farmland soil nitrification and de-nitrification under nitrogen manure application. Rural waste treatment, for example, fertilizing the soil and biogas creation, likewise straightforwardly brings about CH4 and N2O discharges. The change of land use from backwoods to cropland increments soil CO2 discharges. Notwithstanding immediate GHG discharges, farming exercises like apparatus tasks, and compost and feed inputs additionally by implication increment the carbon impression of farming by means of different pathways like petroleum product utilization.
Agriculture a Key Carbon Sinks
Farming moreover addresses a key carbon sink, in spite of the way that it is a huge wellspring of GHG. Horticultural perennials, for instance, field, backwoods, natural item estates and tea houses can get CO2 from the Environment through photosynthesis. It is evaluated that around 13 % of the CO2 emanated by oil based commodity use is consumed by natural vegetation reliably. Vegetation stores are changed into soil natural carbon (SOC) by the activities of microorganisms. In particular, microbial Nero mass can associate with soil minerals to shape a muddled that is a protected carbon pool and the soil carbon can subsequently be taken care of for a surprisingly long time; this carbon tirelessness instrument is known as a soil microbial-mineral carbon siphon. The soil carbon pool (2400 Gt) truly relies upon twice that set aside in the terrestrial vegetation and on different occasions that set aside in the air. The “4 for every 1000 soil carbon overhaul plan,” first proposed by the French service of agribusiness at the Collected Nations Environmental Change Gettogether held in 2015, relies upon the epic carbon-sink breaking point of soils.

Introduction 
Chapter 15 provides a comprehensive analysis of climate change and its profound effects on agriculture and global food systems. This chapter delves into the science of climate change, focusing on its impacts on agricultural practices, climate-smart strategies, and the role of specialized climate change centers and institutes. The chapter begins with an exploration of the impacts of climate change on agriculture, detailing how shifts in temperature, precipitation patterns, and extreme weather events affect crop yields, livestock production, and overall agricultural productivity. It highlights the vulnerabilities of different agricultural systems and regions to climate change. Climate-smart agricultural practices are central to adapting to and mitigating the effects of climate change. This section covers adaptation strategies, such as adjusting planting dates, diversifying crops, and improving water management. It also addresses mitigation strategies, including reducing greenhouse gas emissions through sustainable farming practices and enhancing carbon sequestration in soils. Adaptation and mitigation strategies are discussed in detail, with an emphasis on how these approaches can be integrated to address climate change comprehensively. The interplay between adaptation (adjusting to changing conditions) and mitigation (reducing the root causes of climate change) is examined, emphasizing the need for balanced and coordinated efforts. The chapter underscores the importance of climate change centers and institutes in addressing food security. These institutions play a crucial role in research, policy development, and the implementation of climate-smart practices. They provide valuable data, tools, and guidance for managing the impacts of climate change on agriculture. The impact of climate change centers and institutes on global warming is analyzed, focusing on how these organizations contribute to reducing greenhouse gas emissions and enhancing adaptive capacity. Their role in advancing climate science and supporting climate action is highlighted. Modern concepts in climate change centers and institutes are reviewed, showcasing innovative approaches and technologies that are shaping the field of climate science and its application to agriculture. The chapter concludes with strategies for combating food security and global warming challenges. It emphasizes the need for continued research, international collaboration, and the adoption of effective climate-smart practices to ensure sustainable agricultural systems and enhance global food security.

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

Climate change presents horticulture with increasing challenges including heat stress, water scarcity, erratic rainfall, extreme weather, new pest pressures, and changing crop suitability. This chapter examines strategies for developing climate-resilient horticultural systems through improved cultivars, efficient irrigation, protected cultivation, mulching, canopy management, soil-health practices, and diversification. Climate-smart production also requires better forecasting, monitoring, risk management, and resource efficiency. Future horticulture is expected to integrate biotechnology, artificial intelligence, precision agriculture, automation, renewable energy, and resilient production systems. The chapter emphasizes adaptation rather than dependence on a single technology, promoting integrated approaches that maintain productivity, quality, profitability, and ecological sustainability under changing climatic conditions.

In provincial areas of non-industrial nations, over 70% of the populace actually relies upon agriculture . Be that as it may, financial emergencies, informal land distribution and Climate change issues have ruined endeavored gains in agricultural efficiency and related rustic improvement results. Innovation pushed advancement has generally driven farming to the brink of another improvement that can influence plant variety and yield, yet additionally climatological and financial results. The idea of economical agriculture has become progressively advocated as examination and cultivating networks accept that efficiency with natural and social outcomes should be sensibly adjusted. Agriculture of created countries has basically benefitted of this idea overall during the 1990 s. To find success around the world, broad exploration should be led not just for enormous scope farmers in created countries yet additionally for limited scope ranches in agricultural countries. Climatic smart agriculture saves biodiversity by taking on sound, multifunctional, and multi-trimming approach through plan arranged spatial preparation and stream among them. Here, a spatiotemporal information driven worldview for detecting observing and coordinating agricultural Climate has been proposed to upgrade the utilization of Climatic smart agriculture framework. As an excursion towards maintainable coordinated cultivating, computerized farming offers different open doors for universal systems administration and computerized resources through information sway. The exploration issues are basically worried in the combination of different information archives with administration information, open access information, institutional information, and space explicit information from end clients. Because of the mix of heterogeneous sensors and advanced stages in agriculture, the information typology is getting more extravagant, and how much information is continually expanding.
Feedstocks assume a significant part in the comprehensive advancement of non-industrial nations that depend vigorously on agriculture. It has been standard that farmers must be actually present on their fields during each

Climatic statistics applies quantitative methods to weather and climate observations, transforming raw records into information for forecasting, planning and resource management. This chapter explains how averages, variability, distribution, trends and extremes describe climatic behaviour over time and space. It introduces climate normals, measures of central tendency, dispersion, skewness, kurtosis, data quality, missing-value treatment, homogenization and outlier detection. Statistical interpretation helps distinguish short-term weather fluctuations from long-term climatic patterns. In agriculture, these techniques support crop planning, drought assessment, rainfall characterization and risk management. The chapter establishes the statistical foundation required for scientifically examining climate variability and its influence on crops, ecosystems and agricultural resources.

10.1. Co-operative marketing

Private agencies dominate Indian food grains trade.

High marketing charges and prevalence of malpractices.

Progress of regulated markets is not uniform in all areas.

Need for strengthening co-operative organization in marketing of farmers produce and supply inputs at right price and time.

Soil sample collection is the first and most important step for soil quality analysis. A soil sample collected with due care and proper procedure is essential for getting reliable result of the analysis. The sample should represent the field and for practical purposes, an area of about 0.5 hectare is considered as one sampling unit. In case of conspicuous variation observed in the field in terms of texture, colour, slope etc, separate samples should be collected from areas differing in these attributes. In other words, sample should be collected from an area in the field with similar characteristics as seen through normal visual observation. Sampling should thus be avoided from areas like near trees, permanent vegetations, manure pits, manure piles or recently fertilized fields.

Soil Sampling procedure

1. For a particular field unit, one composite soil sample is prepared out of the samples collected from 7-8 spots distributed across the field unit. The entire field is covered by moving in a zig-zag manner from each sampling spot.
2. For each sampling point or spot, scrapping off the surface litter such as grasses or crop residues is done. Then, a “V” shaped pit of 15-20 cm length and of equal width is made. Depth of sampling depends upon the requirement and on the type of crop. For field crops like paddy, wheat etc, samples are collected from 15 cm depth. From the “V” shaped pits, take outslice of ½ inch thickness from both sides of the exposed pit surfaces from top to bottom.
3. The soil samples so collected from the 7-8 points are mixed thoroughly by hand and then is reduced to about 500 g by quartering process. The quartering process consists of a procedure in which the entire soil mass is divided into four quarters; the two opposite ones are discarded and the remaining two are remixed. This process is repeated till about 500g soil is obtained.

Soil is analyzed to know the nature of soil, to classify and advocate to farmers about the peculiarities of the soils and how much of fertilizers should be applied for better crop production.

A composite soil, of course, can not be moved to into a laboratory. The value of the laboratory work depends upon care in sampling. Each soil sample needs to be a fair representative of the specific area or horizon worth sampling.

If the sample is to be a representative of an area, it is necessary to take large number of samples spread over the area, pool them and sub-sample it so as to get a sample of desired size. For soil survey work, samples are collected from a profile which is typical of the soil of the surrounding area.

Precise collection and processing of soil sample is the first and foremost step for carrying out any soil study, therefore it is essential to collect the coil sample very accurately keeping in view the variations in slope, colour and texture of the soil management aspects. Soil sampling should be avoided from non-representative sites like recently fertilized plots, bunds, channels, marshy tracts and spots near trees, wells, compost piles etc. It should be kept in mind that erroneous samples will never yield accurate result in spite of very improved method of analysis. The depth of sampling may vary according to the need of soil study and extent of rhizosphere. However, in general the sampling depth for field crops is the plough layer (0 - 15 cm) but it could be up to one meter or as per the purpose of the study. Soil samples in dry farming areas should be taken depth wise as the roots of the crops in this conditions reaches to deeper layers in search of water and nutrients.

Mainly two types of soil samples (disturbed and undisturbed) are used for determining the physical properties of soil. The disturbed soil samples are used for determination of particle size distribution, particle density, aggregation, column studies for diffusion-dispersion coefficients and soil-water diffusivity. Whereas, undisturbed (core) soil samples are used for the estimation of bulk density, porosity, retention and transmission characteristics of air and water.

Soil is a mass of large variability and thus its sampling is the most challenging problem for any soil analyst. Practically, soil sampling is a two step process which includes (i) collection of soil from homogeneous unit and (ii) processing which in turn includes drying, grinding, sieving, mixing, partitioning and storing.

1.1. Sources of Error in Soil Chemical Analysis

Different sources of error involved starting from soil sampling to chemical analysis of a sample can be divided into three main groups:

1. Sampling error : This error results from variability among the different samples drawn from same soil unit with respect to the objective of sampling.
2. Sub-sampling error : This error is due to variability introduced among sub samples of the same soil sample.
3. Analytical error : This error introduced due to variability from one chemical determination to another on same sub sample.

Soil is a mass of large variability and thus its sampling is the most challenging problem for any soil analyst. Practically, soil sampling is a two step process which includes (i) collection of soil from homogeneous unit and (ii) processing which in turn includes drying, grinding, sieving, mixing, partitioning and storing.

Soil testing identifies various constraints in soil that limit crop production. Fertilizer recommendation and soil management practices to be adopted are based on the soil test report. Soil testing starts with collection of soil samples from the field
and ends with interpretation of soil test results leading to necessary recommendations for increasing crop production.

This chapter explains how representative soil samples should be collected, labelled, transported and prepared for analysis. It identifies essential sampling equipment, including spades, khurpis, augers, trays, sampling bags, markers and polythene sheets. The recommended procedure involves dividing land into uniform sampling units, collecting soil from several well-distributed locations and combining these portions into a composite sample. The chapter describes V-shaped sampling cuts, suitable sampling depths and sample reduction through quartering. It also lists the field information that should accompany each sample. Procedures for air-drying, grinding, sieving and mixing samples are presented, together with precautions for avoiding unusual areas and contamination.