eChapters

Introduction

The term “Integrated Nutrient Management” refers to the process of ensuring that the fertility of the soil and the delivery of plant nutrients are kept at an optimal level in order to maintain the desired level of production. This is accomplished by using an integrated approach to maximize the advantages that may be obtained from all conceivable sources of organic, inorganic, and biological components. Due to the fact that it supplies plants with anchoring, water, and nutrients, soil is an essential component for crop development. It is common for soils to have a certain amount of organic and mineral nutrient sources; but, in order to improve plant development, it is often necessary to supplement these soils with external treatments, sometimes known as fertilisers. It is common practice to apply fertilizers in order to boost the fertility of the soil, encourage the development of plants, increase crop yields, and provide support for agricultural intensification. Generally speaking, fertilizers may be categorized as either organic or mineral. Manure, compost, seaweed, and cereal straw are all examples of organic fertilizers. Organic fertilizers are created from components that are either plant or animal based. In general, organic fertilizers have lower amounts of plant nutrients because they are coupled with organic matter, which enhances the soil’s physical and biological features. This results in the soil having better qualities. Mineral fertilizers that are based on nitrogen, potassium, and phosphate are the ones that are used the most often. According to the International Food Policy Research Institute (1995), in order to satisfy the ever-increasing demand for food throughout the world, it will be of the utmost significance to make the most efficient and well-balanced use of nutrient inputs from mineral fertilizers. Since 1960, the usage of mineral fertilizer has expanded by approximately fivefold, which has greatly supported the expansion of the world population. According to Smil (2002), nitrogen-based fertilizer has contributed an estimated forty percent to the gains in per-capita food production over the previous fifty years. In spite of this, mineral fertilizers should not be the only means by which crop nutrient needs are satisfied. This is because environmental issues and economic limits make this situation impossible. As a result, Integrated Nutrient Management has to be used in order to encourage the efficient utilization of all nutrient sources, which includes organic sources, recyclable wastes, mineral fertilizers, and biofertilizers (Roy et al, 2006).

Introduction Soil management in horticultural crops refers to the deliberate and systematic approach of caring for soil to optimize its health, fertility, structure, and overall quality to support the growth and development of horticultural plants. It involves a range of practices aimed at preserving and enhancing soil resources, including soil testing, nutrient management, irrigation scheduling, erosion control, and organic matter addition. The goal of soil management in horticultural crops is to create and maintain an environment in which plants can thrive, maximizing crop yields, quality, and sustainability while minimizing environmental impacts such as soil erosion, nutrient runoff, and soil degradation. By implementing effective soil management strategies, horticultural growers can ensure the long-term productivity and viability of their farming operations, while also promoting soil health and resilience in agricultural ecosystems.

Current Soil Conditions

A study conducted in 2016 over 75 fields revealed that soil compaction was present in 70% of annual crops and 60% of perennial crops. Most of the soils used for both annual and perennial cropping were in a moderate condition. However, the soil condition for established crops was improved by performing cultivations before planting. Nevertheless, some soil formations exhibited instability, especially on soils with a lighter texture and a low content of organic matter. The majority of soil cultivations successfully alleviated compaction, however some cultivations had little impact or even exacerbated compaction due to spreading, puddling, or compression when performed in damp or wet field conditions. Tillage pans may greatly diminish productivity and overall efficiency of production by impeding drainage and root development. Approximately 60% of fields cultivating annual crops and 50% of areas cultivating perennial crops had a well-established tillage pan. Approximately 10% of fields underwent deep cultivation without any evidence of soil compaction, indicating a lack of consideration for soil conditions and the need for subsoiling. The abundance of earthworms in the topsoil may serve as a valuable measure of soil health, and is primarily influenced by the intensity of farming practices and the presence, nutritional value, and consistency of earthworm food sources. Earthworm populations exhibited a general scarcity in both annual and perennial crops, while they were relatively more plentiful in areas with ample crop waste and apple orchards. The regular tilling of the soil is believed to be a significant contributing factor to the very low population of earthworms found in places where crops are grown every year. Fields that had a mustard cover crop reported the greatest populations of earthworms.

Introduction

Soil management refers to a set of practices and strategies employed by farmers and land managers to maintain, improve, and sustain the health, fertility, and productivity of soil in agricultural systems. It encompasses a range of activities aimed at optimizing soil conditions for crop growth while minimizing environmental degradation. Soil management practices include soil testing to assess nutrient levels and pH, the application of fertilizers and soil amendments to correct deficiencies, erosion control measures to prevent soil loss, and conservation practices to enhance soil structure and health. Additionally, soil management involves the integration of organic matter, such as compost and crop residues, to enhance soil fertility and microbial activity. The overarching goal of soil management is to ensure the long-term sustainability of agricultural systems by preserving soil health, supporting crop productivity, and minimizing environmental impacts.

Method of Soil Management 1

. Soil Testing and Analysis: Soil testing and analysis play a pivotal role in soil management for agricultural crops, providing farmers with critical information about soil health, fertility, and nutrient status. By understanding the composition of their soil, farmers can make informed decisions about fertilization, soil amendments, and crop selection to optimize yields and minimize environmental impacts. For example, soil testing can reveal deficiencies or excesses of essential nutrients such as nitrogen, phosphorus, and potassium, enabling farmers to tailor their fertilizer applications accordingly. If a soil test indicates low levels of phosphorus, for instance, farmers can apply phosphorus-rich fertilizers to replenish the nutrient and support healthy crop growth. Conversely, if soil pH is too high or too low, amendments such as lime or sulphur can be applied to adjust pH levels and create optimal growing conditions for crops.

Introduction

Precision agriculture, also known as precision farming or smart farming, represents a ground breaking approach to agricultural management that integrates cutting-edge technologies and data-driven techniques to optimize crop production. This introduction sets the stage for exploring the transformative potential of precision agriculture in revolutionizing traditional farming practices. By harnessing advancements in sensors, drones, artificial intelligence, and global positioning systems (GPS), precision agriculture empowers farmers to make informed decisions based on real-time data and spatial variability within fields. The overarching goal of precision agriculture is to maximize yields, minimize input costs, and reduce environmental impacts by precisely tailoring farming practices to the specific needs of crops and soil conditions. As global population growth and climate change exert increasing pressure on agricultural systems, the adoption of precision agriculture emerges as a crucial strategy for enhancing food security, promoting sustainability, and ensuring the long-term viability of farming operations. Through this introduction, we embark on a journey to explore the multifaceted dimensions of precision agriculture and its profound implications for the future of agriculture.

Crop Production

Crop production refers to the cultivation and management of plants for the purpose of generating agricultural yields. It encompasses a wide range of activities, starting from land preparation and seed selection to harvesting and post-harvest handling. Crop production involves the application of scientific principles, traditional knowledge, and modern technologies to optimize plant growth, minimize losses, and maximize yields. The goal of crop production is not only to meet the demands for food, fibre, and fuel but also to do so in a sustainable manner that preserves the health of the soil, water resources, and surrounding ecosystems. It is a fundamental component of agriculture, playing a pivotal role in sustaining human life and supporting economic development around the globe.

Principles of Crop Production and Management

The principles of crop production encapsulate the fundamental guidelines and practices that govern the cultivation and management of crops. These principles serve as a framework for farmers to optimize agricultural productivity, sustainability, and profitability. Here are some key principles:

1. Soil Health: Healthy soil forms the foundation of successful crop production. Principles related to soil health emphasize the importance of maintaining soil fertility, structure, and biological activity. Practices such as soil testing, organic matter incorporation, and conservation tillage are employed to enhance soil health and productivity. Soil health is a foundational principle in the realm of crop production, influencing every aspect of plant growth and agricultural sustainability. Healthy soil serves as a reservoir of essential nutrients, a habitat for beneficial microorganisms, and a medium for root development. The principles of soil health emphasize the importance of maintaining soil fertility, structure, and biological activity through practices such as organic matter incorporation, conservation tillage, and cover cropping. By replenishing organic matter, optimizing soil structure, and fostering a diverse microbial community, farmers can enhance soil health and productivity. Soil testing is another key principle, enabling farmers to assess nutrient levels, pH balance, and other soil properties, guiding the application of fertilizers and soil amendments. Moreover, conservation practices such as crop rotation, agroforestry, and erosion control help protect soil from degradation, preserving its long-term productivity and resilience. Embracing these principles of soil health not only promotes higher crop yields but also mitigates environmental impacts, enhances water retention, and fosters ecosystem biodiversity, laying the groundwork for sustainable agriculture now and in the future.

Sprinkler irrigation is an advanced method of irrigation in which water is sprayed to air and allowed to fall on the ground similar to rainfall. The spraying of water occurs through nozzle connected to a network of pipes with water under pressure. The rate of application and area of coverage under a sprinkler is regulated by suitable selection of nozzle size and pressure in the system.

History of Sprinkler Irrigation

The sprinkler irrigation has started elsewhere in the world in the early part of twentieth century. Before 1920, sprinkler irrigation was limited to orchard, nurseries and intensive vegetable cultivation. The cost of sprinkler reduced considerably by the development of impact sprinkler and lightweight steel pipe with quick couplers in the 1930s. As a result, sprinkler irrigation began to spread in larger area and to the area of field crops. However, sprinkler irrigation developed mainly after the Second World War with the introduction of lightweight portable aluminum pipe.

Sprinkler irrigation has started in India from mid of 1950s. Due to requirement of high initial investment, the average Indian farmers cannot afford the system and therefore the area under sprinkler irrigation in India was 0.66mha (approx.) out of total irrigated area of 87.80mHa in 1995 (INCID). The sprinkler irrigation was first introduced in India in hilly regions such as Western Ghats in Kerala, Tamil Nadu, Karnataka and in the North Eastern States especially by plantation owners for irrigating tea, coffee and cardamom crops. Since the cost of aluminum pipe is high, to replace it, High Density Polyethylene Pipe (HDPE)/PVC with suitable modification have been introduced in sprinkler system. However, the area under HDPE/PVC piping system is below 20% to the total area under sprinkler irrigation. The remaining area is cultivated under aluminum or steel based sets. The indigenous manufacturing of the system has started in India only 35-40 years ago and there are about fifty numbers of manufacturers till 1996 (INCID). The details of the cultivated area under sprinkler irrigation system in the world and in Indian States are given in Table 8.1 & 8.2 respectively.

Drip system has great promise for efficient utilization of available irrigation water. In our country and elsewhere in the world the scientists are unanimously agreed to adopt drip irrigation method for higher application efficiency and thereby better use of scarce irrigation water. Saksena (1993) reported water losses of only 1-2% in drip irrigation in comparison to 6-9% in sprinkler and 30-35% in surface irrigation method. However, very small area compared to other methods of irrigation so far is irrigated by drip system in our country. Up to 2000 the total area under drip irrigation was 2,59,600 ha in India (Alam & Kumar, 2000). Initial high investment for drip network and pumping system, of course, are discouraging to the most of our farmers. Sharma & Abrol (1993) mentioned that in spite of the very encouraging results and attractive subsidies offered by the Govt. of India, the adoption of the drip irrigation system has not picked up to the expected level. Along with the other reasons they pointed out the high initial cost of the system and lack of research effort on developing cost-effective design suited to local condition are responsible for non-practice of drip irrigation at a considerable scale.

Some research works has been conducted to find out low cost method of drip irrigation. Biswas (1998) developed a manually operated drip irrigation system made of bamboo mains, laterals and sub-laterals. The system and its performance are described below.

Drip Network

The main and laterals of the drip network were made of hollow bamboo pieces each of 3m lengths with 7.5cm and 4.0cm diameter respectively. The sub lateral or the emitters were the bamboo twigs of 0.25cm inside diameter and 1.05-1.10m length to suit the spacing between the plant rows. The mains and laterals were made for the required length in the field by jointing together the sections one after another (Fig. 7.1). The ends of two sections, which contact each other, were made such that one section easily gets inside the other for about 10-15cm.

Introduction

Fertilization is the application of fertilizer for the benefit of the crops. It may be traditional broadcasting or fertigation. In broadcasting method the fertilizer is applied in concentrated granular form. The size of the granules ranges from granular dust to pellet size. These solid fertilizers get dissolved by the rain or irrigated water to leach down the plat root zone. This method results uneven nutrient delivery due to uneven dissolving the fertilizer granules. It may cause burning of plant leaves and root system due to uneven and uncontrolled release of nutrients. Dry fertilizers can volatilize and release gases which may damage or burn the nearby foliage. Availability of fertilizer to the plant root zone largely depends on the temperature and availability of water to dissolve the fertilizers.

In fertigation liquid or water-soluble fertilizer, soil amendments or other products required by the plants is either sprayed on to the plant material or applied to the plant bottom with irrigation water. Foliar application provides high rate of absorption of fertilizer through the leaf/stalk/branch structures of plants. Ground application also provides good consistency in making its way to root zone and plant absorption. Thus, the fertigation provides benefit of increased nutrient absorption; decrease water needs, and reduce the fertilizer and chemical use (Anonyms, 2005).

Introduction

There is different type of distributors available in the market. Depending on the basic principle of working they may be broadly classified into three major groups as below (FAO, 1980).

i. Distributors in which head loss takes place through small diameter tubes

ii. Distributors in which head loss takes place through some orifice control

iii. Distributors in which head loss takes place through a vortex action

There are many adaptations to distributors though the working distributors fall under the above stated basic principle. Tiny perforation in the laterals or porous materials allows leaking out the water serves the purpose of distributors. The compensating type distributors have long path in it to dissipate the energy and drips almost same rate within certain range of pressure variation. Whatever may be the distributors proposed to be used, the discharge characteristics should be known. The discharge characteristics should be provided by the manufacturers and preferably certified by any authorized body; otherwise to be tested by the designer before recommendation to large-scale use.

The pipe network in a drip system consists of a mainline, sub mains, laterals, and distributors. The layout of the pipes depends on the physical factors like shape and size of the area, topography and any other obstacles in the field. In any field there may be the scope of different layout of the pipes. The most economic one should be selected. In general, contour line is followed in laying the laterals in sloping land, sub main length usually be shorten in uphill and equally spaced laterals on either side of a sub main in a flat land provides good layout.

Hydraulic Formulae /Head Losses in Pipes

There are numerous equations for solving the head loss in pipes. The most commonly used are the Darcy-Weisbach, Hazen-William and Scobey’s.

Crop Water Requirements

In designing an irrigation system, the primary objective is to know the water requirement of crops. Water requirement of crops are determined either by f ield cultivation or by estimation through commonly used empirical formulae such as Blaney Criddle, radiation, Penman or pan evaporation method.

Definitions

Crop water requirement or evapotranspiration (ETcrop ): It may be defined as the rate of evapotranspiration of a disease free crop growing in a field of not less than one hectare under adequate fertility and water supply so that full productive potential can be achieved in prevailing environment. Evapotranspiration requirement of a crop refers the ETcrop and expressed in mm/day.

Reference crop evapotranspiration (ET0 ): It is the rate of evapotranspiration from an extended surface of 8 to 15cm tall green grass of uniform height, actively growing, completely shading the ground and not short of water. ET0 may be computed by using the empirical formulae and meteorological data for the specific period.

In drip irrigation water is distributed throughout the field from a system of pressurized pipelines. The pressure must be sufficient to overcome the frictional losses and elevation differences. The system also deserves discharge from all the emitters and the emitters must dissipate the pressure difference between the inlet to emitters and atmospheric pressure.

The flow through the drip pipes may be laminar or turbulent or a combination of both. The laminar flow is characterized by the layers of cylindrical tubes of which the maximum velocity is at the center about double of the average velocity. The turbulent flows having pulsatory cross current velocities and maximum velocity is about only 1.25 time of the average velocity. Turbulent f lows loss more energy than laminar flow due to development of the cross current velocity.

Reynolds Number

The criterion for distinguishing the flow from laminar to turbulent was developed by Osborne Reynolds (1842-1900) and was named as Reynolds number; Re . The Reynolds number in circular pipes flowing full is expressed as

Introduction

Drip irrigation is an efficient method of application of water at the plant bottom at a rate nearly equal to the consumptive use rate of the plant, thereby minimizing the conventional water losses like percolation, runoff and evaporation from soil. It is a process of slow application of water on, above or beneath the soil by the surface, sub-surface, bubbler, and spray or pulse system. Fertilizer can also be applied with the drip water. Emitters or applicators are placed closed to the plants and used to spray water in the form of drops, tiny streams or miniature spray. In the drip system water applied from the point source advances in all direction in the soil outward from the source. Drip irrigation is essentially a low rate, low pressure, frequent and long duration application of water in plants root zone area.

Drip irrigation is also called as localized irrigation, trickle irrigation, daily f low irrigation, diurnal irrigation, drop irrigation, sip irrigation, and micro irrigation. A particular name is being popularized in any area depending on the choice of the people of that area. The International Commission for Irrigation and Drainage (ICID) has recommended the term micro-irrigation while the American Society of Agricultural Engineers (ASAE) has preferred drip irrigation. In India it is told as drip irrigation.

Introduction

Agriculture is the backbone of every country. It largely depends on climate and its changes. Over the last few years climate change has affected crops, cropping systems, patterns and the ecosystem hugely. Climate change is caused by greenhouse gases in the atmosphere, which results in global warming (Aydinalp and Cresser, 2008). The rising temperature, melting of glaciers, loss in vegetation cover, frequent occurrences of drought and floods are some of the issues that have raised concern among the environmentalists. The change in temperature and precipitation patterns alters the traditional growing seasons. Climate change is expected to influence crop and livestock production, hydrologic balances, input supplies and other components of agricultural systems (Adams et. al., 1998). Vulnerability of climate change depends on physical, biological and socio-economic characteristics. Low income populations dependent on isolated agricultural systems are particularly vulnerable to hunger and severe hardship. These populations are already barely food-sufficient, even the slightest decline in yields could be very harmful in these areas. The most negative effects are foreseen in dry land areas at lower latitudes and in arid and semi-arid areas, especially for those reliant on rain fed, non-irrigated agriculture (Aydinalp and Cresser, 2008). The rise in temperature cause stress in crops and reduce yields and productivity. Crops that are sensitive to temperature during the growth stages are affected a lot. A shift in growing season is being seen due change in temperature. Irregular and altered patterns of rainfall are severely affecting the crops and water supplies for livestock, which in turn has increased the occurrence of floods and drought, causing soil erosion, disrupting harvesting schedules. Occurrence of new pests and diseases are seen in the places having warmer temperature. Altered temperature has altered the life cycle of pests and intensity of infestations. Rising of sea water level and increased evaporation leads to intrusion of salt water into fresh water making irrigation water more saline harmful to crops. Livestock are sensitive to heat stresses which in turn reduce livestock productivity and increase mortality rates.

Introduction

Climate change may advance more rapidly than anticipated, introducing novel environmental conditions for cultivating horticultural crops. The rise in atmospheric CO2 levels from non-renewable energy sources combustion drives global average temperatures, altering weather patterns worldwide with regional variations (Stocker et al., 2013). Currently, certain regions are already experiencing the effects of extreme weather events such as heat waves or frost, while prolonged droughts pose a growing threat to global food security elsewhere. Climate changes may yield both positive and negative outcomes, but they will undoubtedly alter production conditions and product quality (Kaufmann and Blanke, 2017).

Elevated temperatures can enhance the ability of air to hold water vapor, leading to increased water demand. This process can elevate evapotranspiration rates, potentially depleting soil water reserves and causing water stress in plants during dry periods. Fruit production is particularly vulnerable to water stress, especially in regions where trees lack irrigation. Numerous studies indicate that water stress diminishes crop yields and hastens fruit ripening (Henson, 2008).

Introduction

Climate change is widely acknowledged as the most significant contemporary challenge facing humanity. According to a recent report from the Intergovernmental Panel on Climate Change (IPCC, 2022), the situation has deteriorated further, with 3.3 billion people worldwide highly susceptible to climate change. Current unsustainable development practices are escalating the exposure of ecosystems and populations to climate-related risks. Human activities and their impact on the climate and environment are leading to unprecedented extinctions of animals and plants, resulting in a loss of biodiversity and posing a threat to life on Earth. The diversity of microorganisms is fundamental to maintaining a healthy global ecosystem, as the microbial world serves as the life support system of the biosphere. Although the influence of human activities on microorganisms is less conspicuous and less well understood, a significant concern is that changes in microbial biodiversity and functions will impact the resilience of other organisms, affecting their ability to adapt to climate change. Microorganisms play crucial roles in carbon and nutrient cycling, as well as in the health of animals (including humans), plants, agriculture, and the global food web. Microorganisms inhabit all environments on Earth occupied by larger organisms and are the exclusive life forms in certain environments such as the deep subsurface and extreme habitats. Dating back to the origin of life on Earth at least 3.8 billion years ago, microorganisms are likely to persist well beyond any future extinction events. Despite their vital role in regulating climate change, microorganisms are seldom the focal point of climate change studies and are typically overlooked in policy development. The challenge lies in understanding their intricate role in the ecosystem due to their vast diversity and varied responses to environmental changes.

Introduction

Climate change is a deadliest hazard to life on Earth. Global temperature is rising due to greenhouse gas emissions from the usage of fossil fuels, this result in widespread agricultural and fisheries failure, the extinction of hundreds of thousands of species, and whole towns becoming uninhabitable (Lindwall, 2022). Rising global temperatures are severely killing humans and trees, forcing half of all species to move, worsening water-borne and respiratory ailments in people, and jeopardising millions’ food and water security (Isaacs-Thomas, 2022). Addressing these concerns necessitates a worldwide collaboration to minimise greenhouse gas emissions and promote sustainable behaviours. Climate change affects agriculture production, lowers crop nutritional value, and increases the frequency of extreme weather events. These interruptions jeopardise food production, availability, and access, especially in vulnerable countries. Microbes play an important role in soil health, nitrogen cycling, and ecosystem stability. They impact a variety of soil activities, such as organic matter breakdown, nutrient mobilisation, and plant growth stimulation. However, climate change poses a substantial danger to microbial communities, possibly changing their activities and altering ecosystem dynamics (Wang et al., 2022). Transitioning to a low-carbon economy requires a global effort. Mitigation strategies include enhancing energy efficiency, adopting renewable energy sources, electrifying industrial processes, implementing efficient transportation systems, and introducing carbon taxes or emissions markets.

Introduction

Rising temperature, decreasing precipitation, increased frequency in drought and flooding, etc. is making us realize climate change is not some cooked up story. Still there are people who believes climate change is not real. By definition, Climate change is a long-term shift in global or regional climate patterns. This will affect the life of people in many forms: health, food, water, etc. (Table 1). Agriculture is a highly vulnerable field to such weather and climate changes, they can have significant direct and indirect impacts on farm productivity and profitability. Climate change will have adverse effect on crop physiology, growth and chemistry and thus it will cause negative impact on agricultural production. Because of the variation in climate, moisture availability may change, which limits vegetation activity/plant growth, increase in drought/ heat/flooding will the crop growth and yield. Elevated CO2 does not have a profound effect on C4 plants. On the contrary, tissue nitrogen concentrations are higher for C3 species under increased CO2 . Intergovernmental Panel on Climate Change (IPCC) estimates that climate change and elevated CO2 is expected to increase competitiveness of invasive weed. IPCC also estimates that with 1°C rise in global temperature, 5 to 10 per cent yield reduction of major food and cash crops (Pachauri et al., 2014).

Introduction

The “plant disease triangle” is a fundamental concept in plant pathology that illustrates the interaction between three essential components necessary for the development of a plant disease. Firstly, the host plant which refers to the plant species or cultivar that is susceptible to the pathogen. Host plants provide the necessary environment and resources for the pathogen to establish, grow, and reproduce. Secondly, the pathogen which is any organism (such as fungi, bacteria, viruses, nematodes, or other microorganisms) that can cause disease in plants. Pathogens can infect host plants through various means, including direct contact, airborne spores, soil-borne organisms, or vectors such as insects. And thirdly, the environment which encompasses all external factors that influence the interaction between the host plant and the pathogen. This includes abiotic factors such as temperature, humidity, soil moisture, light, and nutrient availability, as well as biotic factors such as the presence of other organisms (competitors, predators, symbionts) that may affect disease development.

The plant disease triangle illustrates that the occurrence of a disease requires the presence and interaction of all three components: a susceptible host, a virulent pathogen, and a conducive environment. If any of these components is missing or unfavourable, disease development may be inhibited or prevented. Any change in ecosystem can affect plant diseases, because plant disease is the result of interaction between a susceptible host, virulent pathogen and favourable environment. If any of the three factors are altered, the progress of any one disease can change. Although interactions among the three factors must be matched, weather is an important variable due to its dynamic behaviour.

Introduction

The world’s food and nutritional security are under serious threat from climate change. Climate changes have significant effects on agriculture by affecting insect pests, their natural enemies, and pollinators as illustrated in Fig 1 (Eigenbrode and Adhikari, 2023). According to Benedict (2003), 13.6% of annual crop loss worldwide is attributed to insect pest attack. Crops, crop pests, natural enemies and pollinators are directly and indirectly impacted by erratic climate. The continuous and anticipated alterations in these insects vary across species, systems, and geographical areas, impeding the development of strong generalizations and forecasts. Moreover, the implementation of “climate-smart” agricultural methods, may have additional effects on ideal management of these insects.

Direct effects on insect pests

Temperature: The most reliable, well-researched, and easily modelled component of climate change is warming. Warming affects physiology, phenology, dispersal, reproduction, development, and survival of insect pests (Bale et al., 2002) as illustrated in Fig 2 (Skendži? et al., 2021). It can be inferred that increased herbivory would be associated with rising temperatures in many cases. High temperature and high humidity are key reasons for whitefly population increase (Pathania et al., 2020). Warming can alter the number of insect generations in Helicoverpa armigera (Lepidoptera: Noctuidae) in China (Huang and Hao, 2020).