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Now-a-days, a watershed management or watershed development has been fully recognized as a unit for over all development of rainfed areas (Gupta, 2006a and b). Hydrological problems such as excessive runoff, large scale soil erosion, inadequate or faulty drainage and occurrence of droughts are the most significant problems in almost all the rainfed areas. These problems, however, can be alleviated through running watershed based development programmes that recognize the natural topography and water movement patterns of the land.

1.1. Watershed development

Refers to the conservation, regeneration and judicious utilization of all the resources viz., land, water, vegetation, animal and human within a particular watershed in integrated manner.

Water drainage area on earth’s surface from which runoff, due to precipitation, flows into a single to a larger stream, a river, a lake or the ocean.

1.2. Concept of watershed management

Planning and design of soil and water conservation structures such as bunds, waterways, overflow structures, water harvesting structure.

A watershed is an area that provides pathway to the surface or sub surface water flow to a given drainage system. The watershed is a hydrological unit. The area of watershed may vary from few hectares to thousands of square kilometres. The watershed development involves effective management of land and vegetation in order to conserve and improve the quantity of water. The watershed development is a comprehensive and sustainable solution to water conservation (Fig.13.1).
The watershed development has several advantages. It helps in
• Conservation, upgradation and utilization of natural resources particularly land, water and vegetation
• Minimise the inequalities between rainfed and irrigated areas
• Promoting cost effective adoptable simple technologies
• Supply water for domestic ,agricultural and industrial use
• Poverty alleviation and employment generation
• Reducing chemical pollution
• Adopting flood control measures by constructing water storage or impounding structures

Agriculture is world’s single largest employer and probably the most weather dependent of all human activities.  Climate and its variability have been and continue to be, the principal source of fluctuations in global food production. Throughout history, extreames of heat and cold, droughts and floods, and various form of violent weather have wretched havoc on the global agricultural production. With the unprecedented increase in population over past few decades, clearly the mankind faces undertaking task to ensure food and nutritional security for all, considering reduced per capita land, reduced availability of water, depleting biodiversity and need to preserve ecology and environment. In India, of the total geographical area of 328 m ha, about 175 m ha (53 % of total) are categorized as degraded land, of which 150 m ha are subjected to serious water and wind erosion (Singh et al. 1981). Crops are sown in about 180 m ha annually. Since it seems very much impossible to bring more area under cultivation we need to achieve greater efficiency in the natural resources use while conserving the environment by placing greater emphasis on understanding and exploiting climatic resources for the benefits of agriculture.

Technical Term                            Definition

Geomorphological Analysis       Geomorphological analysis is the systematic description of watershedís geometry and its stream channel system to measure

                                                   the liner aspects of drainage network, aerial aspects of drainage basin and relief aspects of channel network.

Watershed

A watershed is the area of land where all of the water that is under it or drains off of it goes into the same place. John Wesley Powell, scientist geographer, put it best when he said that a watershed is: “that area of land, a bounded hydrologic system, within which all living things are inextricably linked by their common water course and where, as humans settled, simple logic demanded that they become part of a community.”

Watershed is defined as a hydro-geological unit of area from which the rainwater drains through a single outlet. Watershed development refers to the conservation, regeneration and judicious use of all the natural resources (like land, water, plants, animals) by human beings. Watershed Management brings about the best possible balance between natural resources on the one side and human beings on the other. Human beings and the ecology are interdependent. The changes in the environment directly affect the lives of the people depending on it. A degraded environment means a degraded quality of life of the people. This degradation can be tackled effectively through the holistic development of the watershed. A watershed provides a natural geo-hydrological unit for planning any developmental initiative. The approach would be treatment from “ridge to valley”.

A watershed, also called a drainage basin or catchment area, is defined as an area in which all water flowing into it goes to a common outlet. People and livestock are the integral part of watershed and their activities affect the productive status of watersheds and vice versa. From the hydrological point of view, the different phases of hydrological cycle in a watershed are dependent on the various natural features and human activities. Watershed is not simply the hydrological unit but also socio-political-ecological entity which plays crucial role in determining food, social, and economical security and provides life support services to rural people.

Management of watershed in India

It involves management of water, land, energy and greenery, integrating all the relevant scientific approaches appropriate to socio-economic background for a pragmatic development of a watershed. In practice, it means allowing load free rainfall run off from the watershed. Clear outflow imply management of effective soil and water conservation and generating a lush green carpet in whole of the area. In other worlds, it is greening of a watershed through proper management of land, water and energy sources. The comprehensive development of watershed seems to make productive use of all its natural resources and also protect them is termed as watershed management.

The Banave terraces in Indonesia and those in Nepal, Mediterranean are examples of integration of human elements into a system of land management, which is an early achievement in watershed management. Watershed management is not merely anti-erosional and anti-run off approach but also a comprehensive integrated approach of land and water resources management. The approach is preventive, progressive, corrective as well as curative. Here wasted land resources could be fruit fully harvested into a productive face for rural development.

Watershed is defined as a natural hydrological unit that covers a specific land surface area from which runoff passes through a common outlet or area with common drainage or outlet. In simple terms, it implies a catchments or drainage basin from which water drains towards a single channel. It may extend over a few acres only or may cover thousands of acres.

Watershed management is the integration of technology within the natural boundaries of a drainage area for optimum development of land, water and plant resources to meet the basic minimum needs of the people in a sustained manner.

It is also defined as the development and management of watershed resources in such a manner as to achieve optimum production without deterioration of resources base or disturbing the ecological balance. It is also termed as “Resource centered technology” since it helps in assessment, augmentation and optimal utilization of all natural resources viz., land, water and vegetation, it prevents deterioration of resources and at the same time ensures sustained productivity of land to meet basic needs of people.

As we conclude this comprehensive review of the complex relationships between weather, crop diseases, and disease management, it is essential to reflect on the current state of knowledge and identify areas that require further research and attention. The preceding chapters have highlighted the significant impacts of weather factors on crop diseases, emphasizing the need for a deeper understanding of these relationships to develop effective disease management strategies. Significant work particularly on effects of different weather combinations on pathogen population and disease severity needs to be addressed well in time. Despite significant advances in our understanding of the weather-crop disease nexus, there remain substantial knowledge gaps that hinder our ability to predict and manage disease outbreaks effectively. For instance, the complex interactions between weather factors, crop physiology, and disease development are not yet fully understood, making it challenging to develop accurate predictive models. Furthermore, the impacts of climate change on weather patterns and crop diseases are still being researched, and more work is needed to understand these relationships fully. To address these knowledge gaps and improve our understanding of the weather-crop disease nexus, several action plans are required. Firstly, continued research is needed to elucidate the complex relationships between weather factors, crop physiology, and disease development. This research should focus on developing a deeper understanding of the underlying mechanisms driving these relationships, as well as identifying key weather thresholds that trigger disease outbreaks. Secondly, the development of accurate predictive models that can forecast disease outbreaks based on weather data is critical. These models should be able to account for the complex interactions between weather factors, crop physiology, and disease development, as well as incorporate data from multiple sources, including weather stations, satellite imagery, and field observations. Thirdly, there is a need for more effective communication and collaboration between researchers, policymakers, and farmers to ensure that research findings are translated into practical disease management strategies. This will require the development of user-friendly decision support tools that can provide farmers with timely and accurate advice on disease management, based on weather forecasts and other relevant data. Finally, addressing the impacts of climate change on weather patterns and crop diseases will require a coordinated effort from researchers, policymakers, and

The adjustment and maintenance of soil pH at a value suitable for optimal crop production is the first step in soil management, because soil pH affects soil properties, nutrient availability and plant nutrition. In India, about 30M ha cultivated  land  suffer from high soil acidity (pH < 5.5). These soils are critically degraded and are of poor health producing crop yields, which are often less than 50% of that in normal soils. Due to this, farmers use much less fertilizers for crops (50 to 80 kg NPK ha^-1), since this is not profitable.

In the present system of curriculum changes, participation of all the stakeholders are not actively involved in developing curriculum over the years.

The march of weather factors during crop period is never smooth and regular. Agriculture, because of its dependance on climate is inevitably subjected to unpredictable long and short term fluctuation characteristic of atmosphere conditions. Climate introduces an element of risk in farming which makes it particularly hazardous occupation.

A Weather hazard in this context can be defined as any type of extreme weather condition that can damage the crops and animals leading to abnormal decrease in production and income. The extent to which these hazards create risk depends on the time of occurrence, intensity and duration of the hazard besides the age, stage of development and inherent resistance of the crop or livestock involved. Major abnormalities affecting the crop production are:

Agriculture, the cultivation of life that sustains human civilization, is profoundly intertwined with the rhythms of the natural world. Of all the environmental factors that influence farming, weather reigns supreme, orchestrating a complex symphony of elements that dictate the success or failure of crops. This chapter delves into the intricate relationship between weather and agriculture, exploring how temperature, precipitation, sunlight, and other atmospheric conditions shape every facet of agricultural production.
Weather’s influence begins with the very first stage of a plant’s life. Temperature governs seed germination and seedling development, while sunlight provides the energy for photosynthesis, the process by which plants convert light energy into chemical energy. The availability of water, dictated by rainfall patterns, is crucial for plant growth and nutrient absorption. Wind patterns can aid in pollination but also cause damage to crops.
Throughout the growing season, weather continues to play a critical role. Optimal temperatures are essential for each stage of plant development, from flowering to fruit production. Adequate rainfall, or irrigation to supplement it, ensures healthy growth and abundant yields.

Agriculture, the cultivation of life that sustains human civilization, is profoundly intertwined with the rhythms of the natural world. Of all the environmental factors that influence farming, weather reigns supreme, orchestrating a complex symphony of elements that dictate the success or failure of crops. This chapter delves into the intricate relationship between weather and agriculture, exploring how temperature, precipitation, sunlight, and other atmospheric conditions shape every facet of agricultural production.
Weather’s influence begins with the very first stage of a plant’s life. Temperature governs seed germination and seedling development, while sunlight provides the energy for photosynthesis, the process by which plants convert light energy into chemical energy. The availability of water, dictated by rainfall patterns, is crucial for plant growth and nutrient absorption. Wind patterns can aid in pollination but also cause damage to crops.
Throughout the growing season, weather continues to play a critical role. Optimal temperatures are essential for each stage of plant development, from flowering to fruit production. Adequate rainfall, or irrigation to supplement it, ensures healthy growth and abundant yields.
Extreme weather events, such as droughts, floods, heatwaves, and frosts, can have devastating consequences for agriculture. These events can destroy crops, reduce yields, and disrupt food production, leading to economic losses and food insecurity (Fig. 18.1).

Weather and climate have great influence on farm animal production. The environment in which an animal lives is referred to as its habitat. A habitat includes both biotic (living) and abiotic (nonliving) components of the animals’ environment. Abiotic components of an animal’s environment include temperature, humidity, oxygen, wind, soil composition, day length and elevation. Knowledge of how potential environmental stressors (ambient temperature, humidity, thermal radiation, air speed, etc.) can directly and adversely affect animal performance, health and wellbeing is also required for a successful animal farming. The indirect consequences of weather include their impact on feed quality and availability.

Birds and mammals are warmblooded (endotherms or homeotherms), possessing a thermoregulatory system that maintains a stable body temperature and uniform internal environment (homeostasis) by converting food energy into heat. All metabolic processes generate substantial heat and much of this is retained within the body of homeotherms by insulating layers of fat, feathers or fur. Dairy cattle, like other warmblooded animals, function most efficiently in environments where they can maintain their body temperature at around 38° C. Tissue and cellular metabolism and the underlying biochemical reactions that sustain life and productive functions need body temperature to be maintained within very narrow limits. Relatively small increases in body temperature result in the breakdown of body protein and a significant depression in production.

Climate change, particularly global warming has complex impacts on domestic animal production system affecting feed supply, challenging thermoregulatory mechanism resulting thermal stress, emerging new diseases due to change in epidemiology of diseases and causing many other indirect impacts. So, climate change will have farreaching consequences for dairy and meat production, especially in vulnerable parts of the world where it is vital for nutrition and livelihoods. Due to poor availability of good quality feed and fodders in India, animals are generally maintained on poor quality grasses available in the pastures or are stallfed, mainly on crop residues. India is already deficit in feed and fodder. These shortages would be further aggravated by the adverse effects of global warming on fodder crop production.

Bacterial diseases are a significant threat to human health, agriculture, and the environment. These diseases are caused by pathogenic bacteria that can infect various hosts, including humans, animals, and plants. The severity and spread of bacterial diseases are influenced by various factors, including weather parameters. Weather conditions, such as temperature, humidity, wind, and precipitation, play a crucial role in the development, dissemination, and survival of bacterial pathogens (Fig. 8.1). Fig. 8.1. Bacterial infection on soybean leaves Temperature, for instance, affects the growth and reproduction of bacteria, with optimal temperatures varying among different species. High temperatures can accelerate the growth of some bacteria, while low temperatures can slow it down or even kill them, however every pathogenic bacterium have its own weather window. For example, a daytime temperature of 35°C and nighttime temperatures of 27°C are most favorable for Xanthomonas oryzae infecting rice. Similarly, humidity influences the survival and dissemination of bacteria, with high humidity favoring the growth and spread of many bacterial pathogens. For example, lower soil moisture decreases the chances of infection of Ralstonia solanacearum in tomato plants. Wind and precipitation also impact the spread of bacterial diseases. Wind can disperse bacterial spores and cells, allowing them to reach new areas and infect new hosts. Precipitation, on the other hand, can influence the availability of moisture, which is essential for the growth and survival of many bacterial

Agriculture is the backbone of human civilization, providing food, fiber, and livelihoods for billions of people around the world. Crop yields, which are a critical component of agricultural productivity, are influenced by a complex array of factors, including genetics, soil quality, water availability, and management practices. However, among these factors, weather and climate stand out as two of the most significant drivers of crop yields.
Weather and climate are intimately linked, with weather referring to short-term atmospheric conditions, such as temperature, precipitation, and wind, and climate describing the long-term average atmospheric conditions in a particular region. Together, they form a dynamic duo that shapes the fate of crops, influencing their growth, development, and productivity.
The impact of weather and climate on crop yields is multifaceted. Weather events, such as droughts, floods, and heat waves, can have devastating effects on crops, leading to reduced yields, lower quality produce, and even complete crop failures. Climate, on the other hand, influences the overall growing conditions, determining the suitability of a region for specific crops and the timing of planting, growth, and harvest.
Understanding the complex interplay between weather, climate, and crop yields is crucial for ensuring food security, improving agricultural productivity, and promoting sustainable farming practices. This chapter aims to explore the intricate relationships between weather, climate, and crop yields, examining the ways in which these factors interact and influence each other. By delving into the latest research and findings, this chapter will provide insights into the following key topics:
The impact of weather events, such as extreme temperatures, precipitation, and wind, on crop yields
• The influence of climate on crop growth, development, and productivity
• The role of climate change in altering weather patterns and crop yields
• Strategies for mitigating the negative impacts of weather and climate on crop yields, such as climate-smart agriculture and weather-based crop insurance

In climatology, terms “Weather” and “Climate” have different connotations. Weather refers to the state of atmosphere at any given time denoting the short- term variations of atmosphere in terms of temperature, pressure, wind, moisture, cloudiness, precipitation and visibility. Weather is highly variable. It is constantly changing, sometimes from hour to hour and at other times from day to day. The aforementioned properties of the atmosphere are subject to constant change and their state at any time determines the state of the weather. However, weather elements are not separate rather they are closely related with each other.

David I. Blumenstock, an eminent climatologist has defined the weather in more restrictive sense. According to him, weather is the behaviour of the lower atmosphere with particular emphasis on the atmospheric behaviour which affect the lands and oceans and have a marked influence on the organisms that live upon the lands, within the waters of the earth or in the lower air. For the geographer, this definition of weather is more satisfactory. Since, he is interested more in the working of the lower atmosphere which affects the life of man as well as natural environment directly. Thus, we come across a great many varieties of weather covering a wide range of conditions.