eChapters

Abstract

Rice blast disease (Pyricularia grisea cavara) which is very much weather sensitive, continues to be an enigmatic problem of West Siang District of Arunachal Pradesh, owing to its geographical location and climate. There is an urgent need of a forewarning system which can provide advance information for outbreak of the diseases attack so that protection measures can be implemented before the actual economic damage of the crop occurs. Two most important statistical techniques for disease forecasting viz. regression analysis and artificial neural network were chosen and forecasting models has been developed for the area and analyzed with local weather data to find best fit for the area and also compared with the Support Vector Machine (SVM) based model RB-Pred developed by Institute of Microbial Technology, Chandigarh. The model based on artificial neural network was found to be best with accuracy of 75-80%, with the present data and algorithm. The accuracy can be improved with long archive records and proper implementation and algorithm selection of the hidden layer, of both ANN and SVM based (being special case of ANN) models, for site-specific forecasting.

Soils vary greatly in their organic matter content. For all practical purposes the organic matter content of the soil parallels the soil N content. The C/N ratio of soil organic matter generally falls in the range of 10 to 12. Because of the ease with which Kjeldahl determination can be made, N is often used as an index of soil organic matter content.

3.1. Composition of Organic Matter in Soil

Organic matter constitutes 1 to 6% of the topsoil weight of most upland soils. In a typical grassland soil, 5 to 6% of organic matter may be present in the top 15 cm. Top soils with less than 1% organic matter are mostly limited to desert regions. On the contrary, the organic matter content of soils in low, wet areas may be as high as 90% or even more. Soils with more than 12 - 18% organic carbon (approximately 20 - 30% organic matter) are called organic soils.

Heat units also called growing degree-days (GDD), effective heat units, or growing degree units, are a heuristic tool in phenology. GDD is a simple means of relating plant growth, development and maturity to air temperature. The concept is widely accepted as a basis for building phenology and population dynamic models. Degree day units are often used in Agrometeorology, Agronomy, Entomology and Pathology essentially to estimate or predict the lengths of the different phases of development in crop plants, insects, pathogens etc.

Introduction

A solar collector, the special energy exchanger, converts solar irradiation energy either to the thermal energy of the working fluid in solar thermal applications, or to the electric energy directly in Photovoltaic (PV) applications. For solar thermal applications, solar irradiation is absorbed by a solar collector as heat which is then transferred to its working fluid (air, water or oil). The heat carried by the working fluid can be used to either provide domestic hot water/heating, or to charge a thermal energy storage tank from which the heat can be drawn for use later (at night or cloudy days). Solar collectors are usually classified into two categories according to concentration ratios: non-concentrating collectors and concentrating collectors. A non-concentrating collector has the same intercepting area as its absorbing area, whilst a sun-tracking concentrating solar collector usually has concave reflecting surfaces to intercept and focus the solar irradiation to a much smaller receiving area, resulting in an increased heat flux so that the thermodynamic cycle can achieve higher Carnot efficiency when working under higher temperatures.

India’s economic security continues to be predicated upon the agriculture sector, and the situation is not likely to change in the foreseeable future. Even now, agriculture supports 58% of the Indian population, as against about 75% at the time of independence. In the identical period, the contribution of agriculture and allied sector to the Gross Domestic Product (GDP) has fallen from 61 to 13%. As of today, India supports 16.8% of world’s population on 4.2% of world’s water resources and 2.3% of global land resources. Also per caput availability of resources is about 4 to 6 times less than that of world average. This will further decrease due to increasing demographic pressure and consequent diversion of the land for non-agricultural uses. Around 51% of India’s geographical area is already under cultivation as compared to 11% of the world average. The present cropping intensity is 136% and it has been registered an increase of only 25% since independence. Further, rainfed and dry-lands area constitute approximately 65% of the total net sown area. There is also an unprecedented degradation of land (107 million ha) and groundwater resource, and also fall in the rate of growth of total factor productivity. This deceleration needs to be arrested and agricultural productivity has to be doubled to meet growing demands of the population by 2050. Efficiency-mediated improvement in productivity is the most viable option to raise production of various commodities including horticulture.

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.

7.1. Summary

The present research had been carried out to study the social ecology of arsenic contamination in groundwater; factors, perception and impact on life and livelihood of the selected village of West Bengal and in the end the comparison is made. The study had been conducted at village Mitrapur in the Haringhata block of West Bengal. A pilot study was conducted to understand the area, its people, institution, communication and extension system of these states.

An exhaustive list of respondents was prepared critically with the help of some villagers. From the list, 70 respondents from the village were selected for the study through a non-random snowball sampling method. The primary data were collected with the help of a structured interview schedule by following the personal interview method. The secondary data were collected from our departmental library, internet, Department of Agriculture, West Bengal, Bidhan Chandra Krishi Viswavidyalaya etc. for establishing the conceptual framework of the study.

Three types of Issues are Covered in this Study

• The influence of social, cultural, and/or economic variables on how drinking water poisoned with arsenic affects people’s life, notably their health (for example socio-economic patterns of illness and social),

• Social factors influencing people’s response: especially in relation to other priorities, perceptions of arsenic, and social roles and relationships.

The Asia-Pacific region, particularly the rural areas within CMCs, faces severe climate change impacts, including frequent natural disasters, rising temperatures, and sea-level rise, which threaten agriculture, livelihoods, and food security. Climate- resilient rural development (CRRD) is crucial for mitigating these vulnerabilities, addressing challenges such as agricultural dependency, limited infrastructure, governance gaps, financial constraints, and socio-cultural barriers. Key approaches like climate-smart agriculture, strengthened infrastructure, innovative start-up ecosystems, enhanced access to climate information, and inclusive policies empower rural communities to adapt and thrive. Stakeholders—governments, international organizations, the private sector, and local communities—play complementary roles in driving resilience through policy, funding, technology, and grassroots innovation. Sensitising all stakeholders across countries to mainstream climate change aspects and its impact on livelihoods, among all departments and the information dissemination by these departments to the public and relevant stakeholders regarding the climate change effects needs to be a continuous process. Success stories from Bangladesh

There is widespread belief now that forests can be used to reduce the costs of slowing climate change. While the role of forests in the global carbon cycle has long been acknowledged, recent discussions within the context of the United Nations Framework Convention on Climate Change, as well as efforts to write climate change legislation in the United States, have emphasized the role forests might play. The most recent policy efforts have focused on near-term actions to reduce deforestation in tropical countries. The rationale for considering forests at all in the policy mix stems partly from the physical components of the issue. The world’s forest estate is exceedingly large:

Since the Green Revolution of 1960s, Indian agriculture have been highly dependent on chemical fertilizers, exploitation of ground water for irrigation, intensive tillage etc. to raise the food grain production of the country towards ensuring food security for all. The consequences of these practices resulted in declined and degraded soil health, soil erosion and dried up water capillaries - ultimately posing threat to the sustainability of the future production. This invites the need of affordable changes in the agricultural practices without hampering the production. Conservation Agriculture, as put forward by FAO, is a set of sustainable agricultural practices, aims to conserve, improve and make efficient use of natural resources through management of soil, water and biological resources in aid with external inputs. The three basic principles of Conservation Agriculture include - minimum soil disturbances, permanent soil cover and crop rotation or crop diversification.

Introduction

There is a widespread degradation of natural resource, e.g., soil erosion, nutrient loss, water-logging, salinity, alkalinity, acidity, decline in soil organic carbon (SOC) content, ground water depletion and micronutrient depletion. The major causes are washing away of topsoil and organic matter due to water erosion, intensive deep tillage and inversion tillage, dismally low levels of fertilizer application, mining and other commercial activities, faulty agricultural practices, no or low use of organics, indiscriminate use of herbicides, pesticides, fungicides etc. Other cause is loss of organic matter with higher temperatures, which increase rate of microbial decomposition of organic matter due to adverse effect of climate change. Climate change due to global warming as a result of increased concentration of GHGs in the atmosphere is a well-established fact. Impacts of climate change are experienced throughout the world. Increases in global mean temperature, rise in sea-level, and occurrence of extreme events are the consequences of climate change. These changes may deplete the SOC pool and soil structural stability, increase soil’s susceptibility to water runoff and erosion, disrupt cycles of water, carbon, nitrogen, phosphorus, sulphur and other elements, and cause adverse impacts on biomass productivity, biodiversity and the environment. Climate change is likely to have a variety of impacts on soil quality. In order to restore soil quality, enhance productivity, it is of utmost importance to focus on conservation agriculture practices on long-term basis. Conservation Agriculture (CA) is gaining importance as an alternative to conventional agriculture.

Introduction

The Indo-Gangetic Plain is one of the world’s major foodgrain producing regions. The Indian states falling under this region, viz. Punjab, Haryana, Uttar Pradesh, Himachal Pradesh, Bihar and West Bengal, are also the major rice-wheat growing states spread over 10.5 million hectares in the country. During the past 30 years, agricultural production growth in this region has been able to keep pace with population demand for food in the country mainly due to adoption of green revolution technologies inducing yield growth, followed by area expansion. But this opportunity is ceasing very fast due to limited scope for increasing the availability of arable land and natural resources. The other issue is the conservation of the basic resources of land and water for sustainability of agriculture in the Indo-Gangetic Plain. It is generally believed that the rice-wheat system has strained the natural resources in this region and more inputs are required to attain the same yield levels (Swarup and Singh, 1989; Kumar and Yadav, 1993; Lal et al., 2004). It is, therefore, imperative now to promote alternative technologies that would help conserve the much needed but gradually depleting natural resources while boosting productivity growth in the long-run by maintaining soil health and production environment. As a part of this strategy, conservation agriculture and resource conserving technologies play a major role in sustaining and enhancing the productivity of the rice-wheat system at a lower cost of production.

Introduction

Intensive soil tillage, burning of crop residues and over use of fertilizer and irrigation water under current agricultural practices has accelerated the pace of degradation in Indian agriculture. Intensive soil tillage increases soil erosion and nutrient runoff into nearby waterways. Crop residue burning resulting in loss of plant nutrients and release of greenhouse gases (GHGs) in the atmosphere. Imbalanced use of chemical fertilizer leads to soil compaction, slows down the fertilizer utilization rate and contaminates the local environment. Increasing demand of irrigation water causes water shortage and harms the environment in several ways including increased salinity, nutrient pollution, and the degradation of flood plains and wetlands. In the face of these management and environmental challenges, there is a need to formulate such agricultural practices which improve the productivity of natural resources as well as of external inputs and help to prevent soil degradation. Conservation agriculture (CA) practices such as reduced tillage, residue retention and proper crop rotations offer such solutions. CA also helps in making agricultural systems more resilient to climate change and safeguard ecosystem services.

Introduction

India agriculture is now at turning point as we have travelled a long way after the advent of green revolution. Over the past four to five decades our strategies, policies and actions were guided by goals of ‘self-sufficiency’ in foodgrains production via green revolution. Indian agriculture has been successful in achieving increased food grains production albeit at a low level of satisfaction. While the mission of increasing foodgrains production stands somehow achieved, these gains were accompanied by widespread problems of resource degradation and high factor productivity, which now pose a serious challenge to the continued ability to meet the demand of an increasing population and lifting our people above the poverty line (Tan et al., 2010). Indian agriculture has reached a point where it must seek new directions – those by way of strategies, policies and actions which must be adopted to move forward addressing sustainable intensifications. The past strategies to increase food grains production, however, have resulted in massive exploitation of natural resources, contributing to unsustainable growth; there is need to change this approach in the future. This will call for strategies, which are different than the ones we adopted in the ‘green revolution’ era. High levels of fertilizer use and decreasing resource use-efficiency are increasingly contributing to groundwater pollution and increased emissions of green-house gases (GHGs) (Gupta, 2004). High level uses of pesticides in many areas have become a major health hazard. Thus, with continuously deteriorating resources, widespread problem of soil and water contamination and eroding ecological foundation, sustainability of agriculture is becoming highly questionable (Conway and Barbier, 1990). There is need to seriously debate on the strategies required to ensure that agriculture continues to play a critical role in the overall development.

Introduction

The Indian agriculture is very complex and carrying out multi-functionalities of providing food, nutrition and ecological security besides employment and livelihood for over 700 million people. Indeed, India has made a marvelous achievement in attaining self-sufficiency in food grain production after the induction of Green Revolution which eventually resulted in maintaining all-time high buffer stock in warehouses of our country. Such rosy picture in production trends turned to be bleak in the past few years. There are various reasons behind this. Shrinking resources of prime lands, deforestation and accelerated erosion, deterioration of soil physical environment, increasing waterlogging and salinity in canal irrigated areas, declining water table in well-irrigated areas, poor management of rainwater, lower efficiency of inputs such as water, fertilizers and agrochemicals, rapid industrialization coupled with pollution and environmental degradation and hazards have aggravated the problem. At the same time, increase in atmospheric concentrations of greenhouse gasses (GHG), of which the most common is carbon dioxide (CO₂), is the primary cause of global warming and the Intergovernmental Panel on Climate change (IPCC) estimates that the current greenhouse gases (GHGs) concentrations are 30% more than the pre-industrial level. C is accumulating in the atmosphere at a rate of 3.5 Pg (Pg = 1015 g or billion tons) per annum, the largest proportion of which resulting from the burning of fossil fuels and the conversion of tropical forests to agricultural production. Under such circumstance, there is an imperative need to produce more from less arable land and water through meticulous management of basic agricultural resources such as soil, water and biological inputs.

Introduction

The green revolution is exemplified by too much adoption of high soil disturbance, modern varieties, energy exhaustive technologies, high amount of capital investment and simplification of farming systems (Meeus, 1993), resulting in uniform and featureless landscapes (Nassauer and Westmacott, 1987) in the most intensively farmed arable areas. In post-green revolution epoch, we had experienced a period of remarkable escalation in food productivity, despite rising land values and increasing land scarcity. Farmers from both developing and developed countries get exposed to several production constraints for achieving a sustainable, cost-effective and assured return from their field. Depending upon the circumstances and the scale of farm activities, farmers face varying degrees of climate risk, biotic invasion, and economic uncertainty. Thus, from the context of economical ambiguities, volatile food prices, social pressure to buffer ups and downs of agricultural production and achieving food security for ever growing population and curtailing poverty, farmers must be equipped with novel cultural practices to achieve a sustainable and assured cost-effective grain production. Research experiments throughout the globe found that the principal indicators for unsustainability of agricultural systems are: (1) intensive tillage induced decrement of soil organic matter (OM), structural degradation of soil, accelerated water and wind erosion, reduced water infiltration rates, surface sealing and crusting, soil compaction, (2) insufficient return of organic materials into soil, and (3) monocropping.

Introduction

Persistent use of conventional farming practices based on extensive tillage, especially when combined with removal or in-situ burning of crop residues, has magnified soil erosion losses and swiftly degraded soil resource base. One of the glaring examples for the aforementioned statement is the ‘Dust Bowl’ in the U.S during 1930s in Great plains, where 91 M ha of land was degraded by severe soil erosion (Hobbs, 2007).

One of the primary challenges of our time is to feed growing and more demanding world population with reduced external inputs and minimal environmental impacts (nature paper). Conservation Agriculture (CA) is a set of management practices for sustainable agricultural production without excessively disturbing the soils, while protecting it from the processes of soil degradation like erosion, compaction, aggregate breakdown, loss of organic matter, leaching of nutrients, and processes that are accentuating due to anthropogenic interactions in the presence of extremes of weather and management practices. The organic materials conserved through this practice are decomposed slowly, and much of materials are incorporated into the surface soil layer, thus reducing the liberation rate of carbon as CO₂ into the atmosphere. In the total balance, carbon is sequestered in the soil, and turns the soil into a net sink of carbon. So, CA enhance soil health by improving soil aggregation, reducing compaction through promotion of biological tillage, increasing surface soil organic matter and carbon content, and moderating soil temperature and weed suppression. CA reduces cost of cultivation, saves time, increases yield through timelier seeding/planting, reduces pest and diseases through stimulation of biological diversity, and reduces green house gas emissions.

Machinery development, refinement and adoption for a range of soil and cropping situations will be fundamental in any success to promote conservation agriculture practices. Agricultural machinery or tools, which support conservation agriculture generally refer to the cultivation systems with minimum or zero tillage and in-situ management of crop residues. Minimum tillage is aimed at reducing tillage to the minimum necessary that would facilitate favorable seedbed condition for satisfactory establishment of crop. Zero tillage is however an extreme form of minimum tillage. With the development of direct drilling machines, almost all research work was attempted to define the responses of direct-drilled seeds in relation to soil micro-environments. Different designs of direct drilling machines viz. zero till drill, no till plant drill, strip till drill, and rotary slit no till drill have been developed with controlled traffic measures for energy efficient and cost-effective seeding of crops without tillage. In this paper various issues, challenges and prospects of conservation agriculture in India has been discussed.

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
The richness of a country can be measured by its biological diversity. It is essential to both human existence and financial security. The most basic concept of biodiversity is expressed by the diversity of creatures. Biodiversity is represented by the supplies of food, clothing, shelter, and medicines provided by plants; by the sources of food, assistance, wild life, and human resource efficiency provided by animals; and by the patterns of variation seen in the microbiological world. More than 20,000 kinds of ants, 3,000,000 species of beetles, 28,000 species of fish, and almost 20,000 species of orchids would be hard for the average person to believe.
Definitions
• The collection and interplay of genes, species, and ecological diversity in a specific location and time is known as biodiversity. Different genes, species, habitats, and their relative abundance are all included in the phrase biodiversity.
• The portion of nature known as biodiversity comprises the genetic variations between individuals of the same species as well as the variety and richness of all plant and animal species at various spatial dimensions, such as a region, a nation, and the entire planet.
• “The diversity of life, which encompasses ecosystem or community diversity, species diversity, and genetic diversity, and includes the entire range of variety and variability within and among living organisms and the ecological complexes in which they occur,” is another definition for it.