Engineering Principles of Precision Farming: Pathway for the Developing Countries to Ensure Food Security

Abstract

Precision agriculture is the precise application of the inputs through the use of modern tools and technology to optimize crop production while maintaining soil fertility. Development in precision agriculture is required as environmental sustainability is considered to ensure the food security of the swiftly growing population globally in general, and for the people of developing countries in particular who are mostly at risk of food insecurity. The use of variable rate input through the variable rate technology for crop input such as seeds, lime, fertilizer, and pesticides is an effective management strategy to address the field variability. The reactive approach of precision agriculture requires the updated and latest technology of electrical and mechanical systems for the formation of variable rate technology. The two approaches of precision agriculture based on the predicted approach or reactive approach have different issues and levels of complexity. Both approaches have benefits and limitations in the application, and both will be used in the future for effective management. In this era, most of the technologies are commercially available, but their effective utilization and implementation require the capacity building of the farming community. The effectiveness of the adoption of the variable ate technology will not provide equal benefits to the farming community, but it will reduce the environmental hazards resulting from unrestricted use of agricultural inputs. The adoption of precision agriculture through the variable rate technology will not provide equal economic benefits, but it will provide the route path to select suitable technologies for better crop production while maintaining system sustainability. The use of GPS, GIS, and remote sensing has provided the opportunity to map the field variability and factors affecting the optimum crop production, especially in the era of climate change. The sensors and ICT application improve the measurement and evaluation of field variability, and decisions are made for the improvement of crop production. The introduction of Agricultural Robotics and Unmanned Arial Vehicles increases the ease of adoption of precision agriculture technologies at a high resolution. The drone technology reduces the labor effort from the field evaluation to input application and mapping for the delineation of the management zones.

1 Basics of Precision Farming

Precision farming is one of the ten new and latest methods in modern agriculture practices (Crookston 2006). It is often described as the application of the right amount at the right time in the right place. Accordingly, precision farming on the global scale was been applied to millions of hectares of agricultural land since the 1980s. The major focus is on the following aspects of precision farming: history and current status of precision farming in developed and developing countries; new developments for precise land preparation, precision sowing machinery, and its working principle; variable rate technologies for fertilizer and spray application; the application of geographic information system and its types and application in farming; the use of geo-positioning system and differential global positioning system; soil sampling and interpolation techniques using satellite systems, soil spatial variability analysis, basics, and application of sensing technologies; various types of proximal sensors used in farming for plant nutrients; soil spatial variability mapping and management; crop yield monitoring techniques; map-controlled application; information and communication technologies; internet information access; computer software for management and precision farming; introduction to agricultural robotics; and unmanned aerial vehicles. The aforementioned techniques are applied for the improved crop production while maintaining soil health and environmental sustainability. The use of information technology is extended into the agriculture sector to fine-tune crop inputs in order to improve production and profitability. In its simplest form, the basic of precision agriculture includes the use of sensing technologies and tools for analyzing the variabilities to implement the sustainable decision for improved crop production.

2 The History and Current Status of Precision Farming

From a historic perspective, it is interesting to note that major changes in agricultural technology have been met with ridicule and controversy. The conversion of farm power from horsepower to tractors was difficult in many areas of the world. Milk transportation in the plastic canes was the practice from the dairy farm and continued in the developing countries. Shifting from the cane system to the chiller-based system was still a challenge for many people as it was thought to compromise the quality of the milk. Similarly, the revolution in corn production through the introduction of hybrid seeds was considered as being against nature. Similarly, in precision agriculture, the world is still facing the issue of major technological changes. The basic concept of agricultural accuracy, data collection, and decision-making based on that data has been around for many years. This was easy to do without any technology in small sections; as the size of the farm increases, however, this was no longer possible. Large farms need new techniques and tools for improved crop production under optimum resource utilization. The geographic information system (GIS) was probably the very first precision farming tool adopted in precision agriculture practices. In the 1960s and 1970s, GIS was only used by the researcher, and its commercial use was not very well established, especially among the farming community. GIS is a very sophisticated precision farming tool, but its adaptability was not very recognized at the time. Other devices were also developed from the 1980s to 1990s, such as yield monitors and nitrogen-testing sensors. The most important component of all of these was the global positioning system (GPS) integration for the site-specific management based on the location determined by the GPS receivers. The sensor technology is improved for the assessment of the soil’s physiochemical condition at the real time. The innovation in the sensing technology triggers the evaluation of the field variability for the purpose of assessing the better crop production to ensure the food security.

Agricultural growth was accelerated dramatically in the last 100 years. This has been a combination of improved practices and the introduction of different technologies. Under these developments, farming shifted from subsistence to the commercial level. These changes in growth were due to the introduction of the new techniques and technologies that transformed the agriculture industry into a profit-driven one rather than one grounded in subsistence. Still, there is a desperate need to adopt the innovation and emerging technologies in agriculture to ensure the food security of the swiftly growing population. Farmers need sound judgment of the variability, and that is the key step before the adoption of technologies to increase yields while reducing the input costs. This type of decision poses significant challenges to the farming community for improved crop production. For example, in addition to the practical information available about the need for water or plant nutrients, farmers often spent more than the required amount. In addition, farmers had to put up with the labor-intensive testing of crops for hundreds of hectares to avoid any problems. Features such as these have enabled technology companies to meet their needs by providing the technologies to the farmers for better decision-making based on the fine resolution information collected through these technologies. This is considered the service-based precision farming concept.

Precision agriculture is the site-specific crop management practice based on the optimization of the water, fertilizer, and pesticide application in a controlled manner in order to reduce wastage and sustain the environment. The key purpose of precision farming is to equip farmers with the latest technology to improve production and profitability by applying the right amount at the right time in the right places.

Precision farming is one of the major pillars of the green revolution. The global increase in crop production was found in the 1930s and late 1960s due to technology transfer and its increased adoption in agriculture practices. The core objectives were to transfer the latest technology for better crop production. One of the important technology transfers in the field of agriculture was the introduction of GIS in the management of sources. In addition to these improvements, the green revolution also brought about the efficient utilization of the chemical fertilizer, effective water management practices, and high-yield variety utilization.

3 Precision Agriculture Scope

The agriculture industry is one of the world’s major industries. In many countries, GDP’s highest contribution is through agriculture production. In some countries such as Pakistan, agriculture can be seen in low-lying farm production, and there is misuse of crop inputs. The agriculture system is divided into two main categories in the majority of the developing countries: small landholding farming and large corporate farming. The agriculture sector in the developing world is facing the stress of low-yield production from these small farmholding communities due to the unavailability and less adaptability of the engineering technologies in crop production. The list of the major problems in this sector includes reduced yields, the increase in input prices, power shortages, water shortages, and the reduced acceptance of agricultural products in international markets. In addition, the lack of subsidies on agriculture requirements, the lack of availability of agricultural inputs, the shortage of information from social media, negative agricultural policies of the government, lower returns, and the decreased availability of irrigation water were having a negative effect on the agricultural community and farmers.

The established practices in the farm management in the majority of the developing countries are based on the general recommendation of the inputs for the whole field. Field sizes may vary from one acre to less than ten acres under this decision. This increases the initial costs due to the inefficient application of chemicals and increasing trends in the environmental issues, in particular the degradation in the quality of groundwater. Before the evolution of agricultural machinery in the world, farmers used a variety of pesticides to make small plots of land. Now advances in the agriculture machinery provided large-scale operations timely and efficiently. Similarly, a significant increase in the use of machinery in the developing countries used for the development of the agricultural lands, but it was very difficult to consider the geophysical variation without the development of technological change. The assessment of the variation was not considered initially with the advancement in the farm’s operational machinery. Now the recent advancement is continued in the assessment of variation while performing other operations in the fields. The technology-driven implements and tractors are launched for the assessment of the field variability while performing the different field operations.

Precision agriculture works on the application of technology to implement the decision made based on the collected information. This is aimed at the use of technology as well as the principles of identification, analysis, and control of spatial and temporal variability corresponding to the production from farms to achieve the maximum benefits, ensure sustainability, and improve plant performance under the protective measures of the resources and environment. It is well established that agricultural accuracy is a multifaceted method that covers the scope of many topics, such as the diversity of soil resources, soil cultivation, irrigation, crop rotation, mechanical operation, plant genetics, and biophysical and chemical inputs. Precision agriculture is the key concept that determines the engineering-based solutions for crop cultivation, the estimation of irrigation water demand, and the design of the sustainable machinery for the site-specific management. In short, the aim of ​​precision agriculture is to design and develop the agricultural resource optimization technologies for improved crop production in a sustainable environment.

The acceptance of precision agriculture is now perceived as a positive change in the developed countries, especially in Europe, Australia, and the United States, even though the adoption in these countries is slow. The adoption of precision agriculture in the aforementioned countries shows that the application of the inputs has been reduced without any decline in the crop yield. The significant adoption of precision agriculture is only possible if the law implementations and agriculture departments of the local governments spread the knowledge of fewer resource utilization and improved farms. The adoption of the new technology in precision agriculture improved crop production in the developed countries and created the challenge for the developing countries to enhance their crop production by adopting the precision technologies to ensure food security. This challenge is widely accepted by different developing countries to ensure optimum crop production. The list of those countries that have now adopted the precision agriculture includes Argentina, Brazil, China, India, and Malaysia (Tiwari and Jaga 2012; Shahid et al. 2014; Shakeel et al. 2014; Amin et al. 2015).

In developing countries, precision agriculture technology is in the developing phase through the indigenization of the agriculture machinery to make it more cost-effective. For example, in the case of Pakistan, technology development started around two decades ago. Before the start of this development, in the region of Indo-Pak, the major farm power sources were human and animals. Later, the introduction of technology such as tractorization became increasingly popular in this region, but the adoption of modern technology is still comparatively rare. The term tractorization defines the adoptability of the tractor at the form with limited improvements. The farming community was practicing only the cultivator as the main tillage tool for all crops as they were shifted from the single tine cultivator driven by the oxen or bulls. The use of the tine cultivator was the main adopted implement since its introduction in many developing countries. None of these implements were able to cater to field variability in order to improve the crop productivity. These existing practices are based on the general recommendations, from cultivation practices to the application of fertilizer, pesticides, and irrigation. The use of modern technology in precision agriculture provides the fine resolution assessment of the field variability of the site-specific crop management. The small landholding of the farming community requires the initial management of the fields to ensure higher crop production. This is a necessary improvement for precision agriculture in order to yield the maximum benefits. The adoption of precision agriculture technology can make a big difference, even in the area of small landholding. This type of farming can be easily managed even for the multicropping pattern. The improved technologies will only provide the targeted inputs more easily to each crop under the multicropping system. The intercropping is a recent advancement to improve the crop production with minimum field practices. The application of the precision technologies will boost its impact with sustainability.

4 Development of Precision Agriculture

The development of precision agriculture began in the early 1990s when Pierre Robert organized the very first meeting on “Soil Specific Crop Management.” Robert had completed his PhD in 1982 under the supervision of Richard Rust in the Department of Earth Sciences, University of Minnesota. His dissertation was entitled “Examination of Some Specific Approaches to soil Management and Plant Management.” In Robert’s book, he continuously stressed that dissimilar patterns in the fields were the result of variations in the soil. He noted that “An important contribution of remote sensing in soil and crop management is not as a real-time tool but as an inclusion in the data management system of plant management.” Carr et al. (1991) conducted experiments on the comparison of the soil-based fertilizer management in Montana and North Dakota. They found that there was no significant difference in uniform economic returns compared to the Montana-based soil management strategy. In North Dakota, the best economic strategy for planting rain-fed barley and wheat was either the use of the same nitrogen fertilizer based on composite soil samples or a flexible N strategy involving combining soil samples and yield terms by making a soil map unit. Flexible fertilizer application rates based on a sample space of a 15.2–30.4 m grid have generally been able to increase crop yields compared to similar techniques but it is found that they also incur additional costs that make these strategies ineffective.

5 Information Flow of Precision Agriculture

Precision farming has the potential for the efficient utilization of natural resources to maintain sustainability. According to the literature, there are a well-defined four definite stages for the implementation of precision agriculture: (a) defining the scale and extent of the soil variability and crop characteristics, (b) describing the causes of the variability, (c) management of the variability on the defined scale and extent, and (d) evaluation of the variability management on the production and sustainability of the resources (Shanwad et al. 2004; Zaffar et al. 2014; Naz et al. 2013; Masood et al. 2013; Saeed et al. 2013; Sultana et al. 2013; Nasim et al. 2012a, b, c, d, e). The basic categories in precision farming include precise assessment of soil variability and plant characteristics and spatial and temporal variability management. In the following lines, the mechanism of precision agriculture (Fig. 1) is discussed.

Fig. 1

Mechanism of precision agriculture

5.1 Variability Characterizations

• Yield variability: Assessment of the yield variability in the fields.

• Field variability: Assessment of the field variability.

• Soil variability: Assessment of the soil’s physiochemical variability.

• Crop variability: Assessment of the crop variability at different spatial and temporal scales.

• Tillage variability: Assessment of the tillage variability.

• Variability in anomalous factors: Variability in the other factors that affect crop production.

• Managing variability: Management of all the aforementioned variability.

• Evaluation: Evaluation of the decision made under the managing variability based on the assessment of the aforementioned factors affecting crop production.

6 Current Practices in Precision Agriculture

Water is the basic resource for agriculture on earth and it requires appropriate and sustainable management strategies. In this regard, precision agriculture plays its role in its efficient use to ensure sustainable agriculture production, even in the water-scarce countries. The demand for good-quality water is increasing as the irrigation sector is facing acute water shortages due to increasing water demands in other sectors and the impact of climate change. Irrigated agriculture is the major consumer of irrigation sources with low efficiency, and improved practices of irrigation are essential to improving the efficiency of water use. Therefore, significant progress has been made in improving water use efficiency in the recent past, and it has been the main focus of many researchers as agriculture is the largest user of available water resources. The concept of real-time control and efficiency of irrigation is in the development stages, but has already shown the potential to save water. The future may see an increase in the use of remote control sensory techniques, wireless communication systems, and flexible sensors in order to improve the efficiency of water use. In many cases, water conservation has been promoted through the use of effective technology for recycling the water for irrigation and eventually increasing the land area under irrigation. Therefore, to achieve water conservation, technology that saves and produces water should be used in conjunction with other methods. Such technology must be used to regulate the distribution of water for the reduction of the losses at different stages of distribution. Factors that affect water use efficiency include engineering and technological innovations, industrial development, environmental factors, and social and economic considerations.

Irrigation is an important agricultural activity which produces food, fodder, and fiber in the soil. In many countries, including Australia, water use and management are of great concern. Most irrigation water is available from rivers and dams and is conveyed by using open channels or pipes to irrigate farms for storage before use or direct application to the root zone. Irrigators who use groundwater often have storage tanks in their areas. At the farm level, commonly used methods of irrigation can be broadly classified as basin irrigation, border irrigation, furrow irrigation, sprinkler irrigation, and drip irrigation systems. Basin, border, and furrow irrigation are older surface-based irrigation methods. In most countries, surface irrigation through the network of the canal system is the most common way to irrigate row crops. In sprinkler systems, irrigation is applied in the form of artificial raindrops through a high-pressure nozzle system. In drip or trickle systems, water is delivered through the network of the pipe system with the help of emitters installed on the laterals, either above or below the ground surface. Drip irrigation, by contrast, is the gradual application of irrigation water available on or under the soil according to the final volume or the absorption rate of a particular soil for use in crop production. A device that drains water from the network of pipe systems under the pressure is called an “emitter” and may be pointed sideways or that may be built on a sideline. The size, width, and shape of the emitter affect the operating pressure in the discharge area, and a small amount of water is released. Flowing water from the discharge areas enters the ground and progresses with capillarity and gravity. Sprinkler systems and drip/trickle are also called pressurized irrigation systems, as they operate under high pressure, which usually involves the use of a pumping unit.

Globally, it has been estimated that about 70% of the world’s fresh water is used to irrigate 25% of the land globally and provides 45% of the world’s food (Thenkabail et al. 2011; Sajjad et al. 2012; Nasim et al. 2011, 2012b). Water for industrial and domestic purposes accounts for between 10% and 20% of all water used worldwide, respectively. Demand for freshwater resources is growing, and this trend is likely to continue to increase with the increasing demand for food and fiber, as well as the negative effects of climate change. It has also led to an increased awareness of the requirement to provide an adequate water supply for the provision of other natural resources. Therefore, this requires increased efficiency in the use of scarce water resources, a concept technically called efficient water use.

6.1 Irrigation Methods and Systems

6.1.1 Surface Irrigation Methods

Surface irrigation is the widely used method to irrigate agricultural lands globally due to easy flow handling, little expertise requirement, lesser management, and no power requirements. Different surface irrigation methods are used, including border, ridge, furrow, bed, furrow, and basin. The adaptability of the relevant method depends largely on the farm size, the availability of machinery, soil type, and targeted crop for production. Water saving varies for different crops, ranging from 30% to 50% depending on the aforementioned factors. Moreover, some innovations such as the mulching of plastic film on beds and surge irrigation have been introduced to further improve the efficiency of surface irrigation. However, surface irrigation methods are assumed to be the least efficient. The innovation of technologies such as laser land leveling and laser grading has significantly improved the water application at the farm level and also increased crop productivity. Both technologies ensure a rapid advance time and an almost similar infiltration pattern, depending on the soil type. However, the laser grading is more suitable for better irrigation efficiency in different soils. The research shows the significant potential of precision surface irrigation in the Indus Basin Irrigation System (Anwar et al. 2016; Chaudhary et al. 2011; Hammad et al. 2010b; Wajid et al. 2010; Usman et al. 2010). The conjunctive water use is also found suitable under precision surface irrigation (Anwar and Ahmad 2020). The working principles of the laser grading is presented in Fig. 2.

Fig. 2

Laser land leveling and laser grading principles

6.1.2 Drip Irrigation

The drip irrigation method is very efficient because it reduces conveyance losses and directly provides water to plants. This increases the yield per unit of water, thereby increasing water use efficiency. Irrigation with a drip system also increases the efficiency of fertilizer application and, as a result, reduces the total production costs. The performance of drip irrigation is not affected by wind speed. Moreover, weeds are less likely to grow in parts of the field that is not irrigated, thereby reducing weed impact on crop production. Ensure uniform crop growth and very high-quality produce due ti timely fertigation. Controlled and frequent irrigation to crop ensures timely crop maturity by keeping the root zone aerated throughout the irrigation period. Daily watering keeps the soil moist and soft, so the roots of plants can easily penetrate. This method is effective for hilly and sloping areas where topography does not allow the surface irrigation systems. Therefore, there is a gained significant adaptability in the hilly areas, especially in the Potohar region of Pakistan. Figure 3 shows the drip irrigation system installed in an orchard.

Fig. 3

Drip irrigation system installed in an orchard

6.1.3 Drip Irrigation Limitations

The drip irrigation system is a highly expensive irrigation system in terms of its initial installation cost. The drip irrigation system requires a source of energy to operate and thus increases the production costs. The successful use of drip irrigation systems requires continuous monitoring and maintenance, which is difficult for the common farmer. If the saline water is used continuously for irrigation, then it affects the soil and demands additional irrigation supplies for the leaching of salts from the root zone. Moreover, salt accumulation can also shock the emitters and create problems with the filter system.

6.2 Sprinkler Irrigation System

In this irrigation system, water is applied to crops through a series of sprinklers which ensure the equal distribution of the water in the field. The irrigation efficiency is reported as being up to 85% and saves 10–16% of the land by removing channels that are otherwise needed in surface irrigation supplies. These sprinklers are connected through the pipelines. The pressure in the system is produced by the pumping unit. By the careful selection of pipe sizes, operating pressure, and spraying spaces, the amount of irrigation water is needed to refill the root zone of the crops by applying the irrigation at a rate less than or equal to the soil infiltration rate. The system can be used effectively in small to large cultivated areas, especially for sandy soils. However, this is not recommended for very fine soils with an infiltration rate of less than 4 mm/h. The sprinkler irrigation system is very suitable for those areas with higher slopes or unusual topography. If soil is vulnerable to erosion, sprinkler irrigation can be used in conjunction with contouring, terracing, mulching, and strip cutting. Fertilizer and pesticide applications can be done economically with the irrigation water by adding small equipment, and the system saves the extra work, time, and cost needed to apply the fertilizers, pesticides, and herbicides. Sprinkler irrigation can be used to protect crops from frost and low temperatures that affect the yield and quality of the crop.

This system allows efficient use of small available water supplies to irrigate shallow soil and provides better control of the installation of water that is suitable for providing light and frequent irrigation and efficiency of the water application close to 85%; it is suitable for vegetable and cereal crops. The system allows the partial or full coverage of the fields, and the chances of the sprinkler system nozzles becoming clogged are less than compared with the drip irrigation system. Figure 4 present the installed sprinkler irrigation system.

Fig. 4

Sprinkler irrigation system

6.3 Types of Sprinkler Irrigation Systems

Based on sprinkler heads and the portability of systems, sprinkler irrigation systems are classified into several types. The most common types of irrigation systems are described below:

6.3.1 Rotating Head Systems

The rotating head sprinkler system consists of the small size nozzles mounted on the riser which are equally spaced and installed on the lateral pipes of the sprinkler system. In this system, the lateral is placed on the ground surface, while the mainlines are buried in the ground below the cultivation depth. The pumping unit is connected to the mainline to provide the sufficient operating pressure. The system is also mounted above the crop high to provide the sufficient irrigation in the targeted areas in a rectangular pattern as the degree of rotation is at 90^o. In this system, spray heads are rotated due to the impact of water and are generally known as impact-type sprinklers.

6.3.2 Perforated Pipe Systems

The perforated pipe sprinkler system consists of the equally spaced nozzles along the length of the pipes from irrigation that is done under the operating pressure. These system works for the small-scale irrigation as the operating pressure varies from 0.5 to 2.5 kg/cm². This level of operating pressure can be achieved by connecting the pipe with the overhead tank. As the nozzles are made on both sides of the pipes, the average area covered mostly falls between 6 and 15 m. The area coverage also depends upon the scale of the operating pressure. The suitable site for this system is considered with the high infiltration soil as the system provides high flow rates. These types of sprinkler systems are considered more suitable for irrigating plants whose height does not exceed 40–60 cm, such as grass, gardens, and small vegetable gardens like the concept of kitchen gardening.

6.3.3 Portable Sprinkler System

These systems use a back pipe with periodic fittings. The side pipe is usually made of aluminum with various lengths of sections, that is, 20, 30, or 40 ft, and has a special connection that connects quickly to each pipe area. The sprinkler is fitted with a single pipe riser to operate above the cultivated plant. The risers are connected to the side where the pipes meet, and the length of the pipe section is selected to match the desired spraying space. The lateral pipe of the system is placed on the same site till the completion of the irrigation to the selected field, and then these lateral are moved to the next position for the irrigation to the next field or the desired field. This type of sprinkler system has low initial costs, but with high labor requirements. It can be used in many crops, such as corn, and the side parts are difficult to move as the crop reaches maturity.

The solid-set sprinkler irrigation system is the most expensive sprinkler system in terms of its capital cost and it is the cheapest in terms of the operating cost. In this sprinkler system, the lateral are placed in fields at the time of sowing and removed before the harvesting. The irrigation flow is regulated through the value system to provide the sufficient discharge at the time of requirement. This system requires extensive labor at the time of installation and at the time of removing the system from the field. In this system, the main pipes are buried under the surface below the depth of cultivation. These types of systems are expensive but operate under the automated system to retain the moisture in the roots according to the requirement.

6.3.4 Rain Gun Systems

The rain gun irrigation system is a specially designed sprinkler irrigation system for the high flow rate and vast area coverage through the high pressure thrust. The working pressure is relatively high among the other designed sprinkler systems with the range of 2–7.5 kg/cm². The flow rate of the rain gun system varies from 3 to 30 l/s and the operating nozzle diameter is about 10–30 mm. The area coverage of the rain gun having the aforementioned specification varies from 27 to 60 m. The rain gun system is very efficient with the equally distributed pressure and uniformity of the water distribution at the whole coverage area. The variation in the radius of coverage and flow rate can be adjusted as per requirement. The trajectory path is easily adjustable to control the angle of application and mitigate the wide effect. The rain gun system is highly recommended for the large coverage field crops which include sugarcane, oilseed crops, pulses, tea, and coffee. Figure 5 shows the working of a rain gun in a maize field.

Fig. 5

Rain gun irrigation system

6.3.5 Central Pivot Systems

The central pivot sprinkler irrigation system is made of counted towers in series, upon which nozzles are mounted. The ending part of the connected towers has the nozzles that also covered the corner areas. One part is connected to the pumping unit, which is also the point of rotation. The time to complete one rotation ranges between one hour and several hours. The performance of the system depends upon the flow rate from the mounted nozzles, the operating pressure from the pumping system, the speed of the rotation, the irrigation water requirement, and the type of soil. Center pivots can irrigate many field plants, but they are sometimes used on trees and vineyards. Linear motion systems are similar to the center pivot systems, with the exception that there is no fixed pipe end. Figure 6 shows the central pivot irrigation system on a large field.

Fig. 6

Central pivot irrigation system

6.3.6 Sprinkler System Limits

The major limitation of sprinkler irrigation systems is their high initial costs and operational expenses due to the requirement of excessive use of power to create working pressure from 3 to 6 bars. Moreover, the requirement of skilled labor for operating the system requires additional costs. The areas having high winds disrupt the equal distribution of water, resulting in uneven irrigation. This uneven irrigation causes the over-irrigation and under-irrigation at some parts of the field. The continuous direct irrigation may cause some fungal disease, leave burning, and damage to fruits due to the accumulation of salts on the leaves. Extensive labor is required to move the sprinkler on large area. A portable system becomes blocked in the case of long trees or plants in the fields. The proper maintenance and care is compulsory to run the system for a longer period and in order to justify the cost. System failure occurs as a result of improper maintenance or the unavailability of skilled labor or a technical operator.

6.3.7 Laser Land Leveling

Traditionally, farmers often used to level the soil in their fields using tractor-drawn plows called scrapers. These are simple implements that comprise a hook and a small bucket to turn the soil from a high point to a low point. Traditionally balanced or unequal soils lead to low levels of irrigation efficiency. A large amount (10–25%) of irrigation water is lost during farm irrigation due to poor management and unequal fields. Over-irrigation in low-lying areas removes soluble nutrients in the root zone of plants and makes the soil less productive. On the other hand, plants receive stress at higher levels, causing growth to be negatively affected. Technological options for advanced production and profit are expected to improve the efficiency of water use and, consequently, increase production. Precision land leveling helps control the beginning of soil salinity, thereby increasing crop production by 3–5%, improving crop development, reducing weed growth, and saving water for irrigation. Laser leveling is a process of smoothing the soil ±2 cm from its central height by using laser-assisted drag buckets to achieve precision ground measurement. Precision measuring the ground involves changing the fields in such a way that it creates a constant slope of 0–0.2%. This practice uses large horse tractors equipped with global positioning and/or laser-guided instruments to move the soil by cutting or filling to create the desired slope.

The laser leveler consists of (1) an emitter which emits a fast rotating beam and is placed on a tripod and (2) a receiver which is carried by a sensor mounted on a tractor near the scraper unit. The received signal then actuates the scrapper through a hydraulic system into cutting and filling level adjustment. The direction of the scraper is fully automated; user error features are removed, which allows for a fairly precise ground measurement. Figure 7 shows the laser land leveling at the research field of Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan.

Fig. 7

Laser land levelling at Khwaja Fareed University of Engineering and Information Technology, Rahim Yar Khan

6.3.8 Benefits and Limitations

The benefits of this system includes the laser-controlled soil accuracy, which helps to improve both plant growth and crop maturity. Laser land leveling increases water efficiency by up to 50%, controls the movement of salts into the soil, and saves irrigation water by about 35–45%. The limitation includes the high cost of laser implementation and the need for a skilled operator to set/adjust laser settings and operate the tractor. However, the government supports these services from its allied departments and, in some countries, provides subsidies to farmers for the purchase of these pieces of equipment.

7 Variable Rate Technologies

The variable rate technology began with the idea of fertilizer application at different rates on different parts of the field based on the requirements in the early to mid-1980s. Gradually, the variable rate technology has come to replace the concept of traditional farming. Similarly, the US university scientists started working on the concept of variable fertilizer application in the late 1980s. The concept of the variable rate of fertilizer application yielded both economic and environmental benefits. The selective application of fertilizers decreased the input cost, improved the efficiency of fertilizer use, and improved crop production. The variable rate application of fertilizer protected the soil and water quality due to the reduction of its application under traditional pattern of fertilizer application.

The use of variable rate input through the variable rate technology for crop input such as seeds, lime, fertilizer, and pesticides is an effective management strategy to address field variability. In the reactive approach of precision agriculture, the on-the-go requires the updated and latest technology of electrical and mechanical systems for the formation of variable rate technology. The two approaches of precision agriculture, based on the predicted approach or reactive approach, have different issues and complexity. Both approaches have benefits and limitations in terms of their application, and they will be used in future for effective management. In this era, most of the technologies are commercially available, but their effective utilization and implementation require the capacity building of the farming community. The effectiveness of the adoption of the variable rate technology will not provide equal benefits to the farming community, but it will reduce the environmental hazards produced due to unrestricted use of the agricultural inputs. The adoption of precision agriculture through variable rate technology will not provide equal economic benefits, but it will provide the route path to select the suitable technologies for better crop production while maintaining the system’s sustainability.

8 GIS Application in Agriculture

The first geographical information system (GIS) was created by Canadians in the early 1960s to store geospatial data and create maps for the Canadian Land Inventory. This information revealed the global potential for agriculture, wildlife, forestry, and recreation. The GIS technology was not particularly familiar about a decade ago, but it is now the most important and widely accepted and utilized tool in the agriculture production system. GIS has become the most important tool for the site-specific crop management through the development of the management zones. These practices are valid for the reduction of the input cost and productivity enhancement. The application of the GIS for the improved crop production is developed based on the real-world information through the random collected data of the fields and the satellite information. The sensing technology used for data collection ranges from agriculture machinery-based sensors to satellite systems.

Precision GPS has become an important tool for workers in the agricultural industry. For farmers, technology provides numerous cost-effective and productive benefits, as well as social and environmental benefits. The use of mechanical sensors to collect information about plants and GPS to immediately record the area used in the field is an important example. The technology, therefore, allows fertilizer to be applied only where it is needed, and the application rate may be changed to target nutrient-free areas. This saves money on fertilizer production and protects the environment by preventing local rivers and streams from overflowing and flooding. Satellites and drone use have grown exponentially in the past few decades in precision agriculture. One of the core challenges in the agriculture system is the management of water resources. Water accounting is the main pillar involved in improving and enhancing water productivity. Remote sensing and GIS made it possible to assess water accounting at different spatial and temporal scales. The management factors for the improved crop production and water management include soil salinity, groundwater level and groundwater quality, surface water supply, rainfall pattern, soil moisture, flood, and drought. The spatial and temporal mapping of all these factors provides sufficient information for the making of better decisions regarding improved crop production.

Satellite-based information has the course resolution than the drone technology. Drone technology collects the very fine resolution information and performs better management operations. The fine resolution data collected through drone technology includes plant-based information such as plant height, plant biomass, the number of plants, weeds and other diseases, and the level of nutrients. The regular monitoring on the large fields is also performed through the drone technology. Drone technology helps the farmers to make real-time decisions. A single drone can empower farmers to make many powerful decisions which will affect the field’s level of production.

The agricultural industry has undergone a major transformation with the introduction of geospatial technology. Over the past few years, the power of the Internet and GIS access and digital mapping have both changed the way in which farmers manage their land and perform their basic functions. GIS allows us to visualize, analyze, and comprehend the vast area of data that is stored and collected daily. It is now possible to give an easy explanation of which crops thrive, the level of pollution, and natural disasters that hinder the production and control of fertilizer use.

9 GPS and DGPS System Use

Site-specific crop management through the delineation of precisely developed zones is very important in precision farming based on the soil and crop yield variability. The distribution of the inputs based on the variability assessed in the farms and delineated zones is also very important for improved crop production. The delineated maps provide the georeference-based information to provide the required amount in the right place. Initially, it was a difficult task to identify within-the-field variability, but the use of accurate GPS made it very simple in the modern era. The GPS-mounted machinery performs these field-based operation very effectively. The connectivity of the four satellites made the accurate decision in the agricultural fields for the application of the crop inputs and other management practices. The approach of changing the real-time difference was chosen over the real-time kinematic position, which involves continuously calculating the phase of data from at least four satellites on both the primary and oriented receivers. When a roaming receiver passes behind a tree, building, or hill, there can be a loss of signal, leading to real-time kinematic failure. The primary motivation for GPS precision farming was to identify compound areas and collect real-time data on grain harvesting position fluctuations. Later, attention to GPS switched to its usage in the areas of agricultural equipment navigation and autosteering. This program comprises hardware, software, and image data, as well as information on geographical surveys, management, analysis, and demonstration. In a conventional integrated system, a GIS may receive, organize, quantitatively analyze, and display various types of digitally identified location data. When these databases are built and covered with fresh combinations in databases, allocation decisions can be made continuously. Figure 8 shows the differential global positing system available at KFUEIT, Rahim Yar Khan, Pakistan.

Fig. 8

Differential global positioning system, KFUEIT, Rahim Yar Khan, Pakistan

10 Geostatistics

The assessment for quantifying the soil variability within the agriculture fields was started during the 1970s and 1980s by the soil scientist. Initially, they started on the assessment of the variability of the soil moisture and soil hydraulic parameters. The use of geostatistics started with the core purpose of assessing the water and salute transport in the unsaturated zones. Similarly, the spatial mapping of soil was also understudied using the geostatistics approach. The application of variable rate fertilizer was not the aim of the soil mapping during this time.

Parallel research on the spatial variability of soil was also conducted. Mulla’s research came to the attention of Max Hammond, a crop consultant working for CENEX Land O’Lakes and Soil Teq, and in 1986, Soil Teq, from Waconia, Minnesota, hired Mulla as a consultant to write software that automatically reclassified and mapped soil fertility sampling data into fertilizer recommendation zones, which Mulla called “management zones.” The integration of the GIS and geostatistics started with this work of precision farming. The use of geostatistics in precision agriculture is extensively documented by Mulla (1988); Swinton & Lowenberg (2001); Hammad et al. (2010a); Oliver (2010) ); Gebbers & Adamchuk (2010); Munis et al. (2012); Nasim & Bano (2012); Khaliq et al. (2012); Mubeen et al. (2013); Hammad et al. (2014).

11 Satellite Remote-Sensing Application

Agriculture, which is the engine of economic growth in many countries, provides essential human services such as nutrition and fiber. The sector has evolved dramatically as a result of technological advancements in the last century, such as the Green Revolution. The Green Revolution, or the so-called third agricultural revolution, enhanced crop output and food security, especially in poor countries, from the 1960s to the 1980s. It included advanced plant varieties, synthetic fertilizers, pesticides, and irrigation. As a result, despite a threefold increase in population density and a threefold increase in food demand since the 1960s, agriculture has been able to supply demand with only 30% of all producers located globally (Pingali 2012). By 2050, demand for food and agricultural goods is predicted to increase by more than 70%. Given the limited availability of agricultural land, a large part of this increasing demand will be met through agricultural intensification, that is, increased use of fertilizers, pesticides, water, and other inputs.

However, heavy use of agricultural inputs also causes environmental degradation, including the depletion of groundwater, reduced groundwater flow, and eutrophication. Excess and/or limited use of natural resources (e.g., soil and water), fertilizers, and pesticides in agriculture production causes economic losses and increases the loss of water and nutrients from agriculture leading to environmental degradation. To achieve an economic and environmental sustainability production system, there is a need to develop strategies that can increase crop production through the increased use of inputs and reduced environmental losses. Precision agriculture has been described in many different ways, yet the basic concept is still the same. Precision agriculture integrates a management strategy that uses a collection of advanced data, communications, and data analytical strategies in the decision-making process (e.g., water use, fertilizer, pesticide, seeds, fuel, labor), which help to improve crop production and reduce water and nutrient loss and adverse environmental impact. Information-based management, site-specific plant management, targeted farming, dynamic technology, and grid farming were all used similarly in precision agriculture. In addition to crop production, precision agriculture has been used to grow viticulture, farming, grazing, and livestock production and management.

Currently, agriculture can be considered as a transition to the fourth most important transformation through the development of information and communication technologies. Emerging technologies, such as remote sensing and GIS, GPS, Internet of Things, big data analysis, and artificial intelligence, are all promising tools used increasing agricultural efficiency and resources aimed at improving productivity and reducing inputs as well as yield loss. Many IoT technology applications use cloud computing, wireless sensor networks, and large-scale data analysis for intelligent farming activities such as automation telephone irrigation systems and intelligent diseases and pest monitoring and prognosis systems. Artificial intelligence techniques, including machine learning, have been in place used to measure evapotranspiration, soil moisture, and crop predictions for automatic use and water accuracy, fertilizer, herbicide, and pesticides. These technologies and tools enable farmers to highlight spatial fluctuations between farms and large plantations that harm crop growth and harvest. This is a modern technology for site-specific development, and implementation management is an important aspect of precision agriculture.

Remote-sensing systems, making use of information and communication technology, typically produce a large amount of spectral data due to the high resolution required in precision agriculture applications. Emerging data-processing techniques, such as big data analysis, practical wisdom, and machine learning, have been used to extract useful information from large amounts of data. In addition, cloud computing systems are used to store, process, and distribute/use such a large amount of application data in precision agriculture. All of this has improved data acquisition, and processing methods are used worldwide, to assist in the decision-making process of field crops, horticulture, viticulture, pasture, and livestock.

In the past, a few studies have provided reviews of remote hearing techniques and applications in agriculture. Land use and land cover development for the estimation of the cropped area assessment and water resource management component estimation at a high-resolution scale is an extensively adopted technique for effective management solutions (Awan et al. 2016; Cheema and Bastiaanssen 2010; Cheema et al. 2014; Cheema and Bastiaanssen 2012; Liaqat et al. 2015, 2016; Waqas et al. 2019). Although some studies have focused on specific areas that used evapotranspiration measurement, such as disease and pest control, others cover more than one application area. Many of these studies have demonstrated the artistic nature of distance-based strategies and their limitations and future challenges.

Remote-sensing systems for precision agriculture and agriculture, in general, can be divided into two categories: (i) sensory platform; and (ii) sensor type. Satellites, aerial, and terrestrial platforms are frequently coupled to sensors. Satellite goods have been regularly used in Pennsylvania since the 1970s. Aerial platforms, including airplanes and unmanned aerial vehicles, have recently been utilized in precision agriculture. In comparison to air-based or satellite platforms, supported systems are dubbed remote-sensing systems since they are placed close to the target location. Many plant indices and mathematical learning methods and equipment, including the neural network and random forest, have been employed to minimize the impact of hyperspectral data to extract significant information on plant conditions. Measurements of chlorophyll produced by sun fluorescence from hyperspectral images have recently been widely utilized to evaluate photosynthesis, plant genetics, and biotic and abiotic stress such as disease and water stress. Even though most modern satellites give high-altitude and transient corrections, most publicly available satellite products are reliable in most precision agriculture systems. The capacity of farm equipment to modify input application costs is dependent on various aspects, including management objectives, field size, and the ability of farm equipment to change input application prices. In comparison to variable fertilizer and irrigation level applications, crop yield and yield rate often require changeable height. Furthermore, weed map design and flexible herbicide administration necessitate a higher level of space fixation than weed sections. When compared to satellites, aerial platforms such as UAVs deliver high-resolution photos. So, UAVs, as well as other grounded platforms or greater flexibility in rendering images in a beautiful and temporary environment.

There are many ground-based remote-hearing stations with working sensors in the area. Applications like Green Seeker and Crop Circle, for example, feature active sensors near the amount of flexible fertilizer available for sale. That’s true; in these systems, daylight variation has less of an effect on the light intensity, allowing for greater precision and viability of the plant index or other crop indicators used to measure plant nutritional condition. Two more sensors (thermal infrared and microwave) that have been placed in recent satellites are increasingly being employed in agriculture. Thermal infrared sensors detect energy emissions by detecting their temperature and can be used to continually monitor plant water pressure, evapotranspiration, and irrigation requirements. Microwave sensors, like heat sensors, balance power by emitting energy from the earth’s surface. Microwave sensors are commonly employed in broad regions to assess soil moisture and plant water use. Microwaves can also penetrate clouds, which is an advantage over other types of sensors that use visible and near-infrared wavelengths.

However, microwave satellite sensors, particularly passive ones, require rough local adjustments. Sensors, on the other hand, are limited to precision agriculture. Microwave data for passive downscale for improved adjustment for use in precision agriculture has recently been created and applied in many ways. Active microwave sensors are frequently used for high-resolution localization; nevertheless, they are extremely sensitive to soil avoidance, which can cause soil moisture content shortages. Overall, many remote sensors and platforms can be utilized to provide high-resolution images, which are necessary for developing and implementing site-specific management. In Fig. 9, the NDVI developed from LANDSAT 7 image is presented.

Fig. 9

NDVI from the LANDSAT Image

12 Sampling and Interpolation Techniques

Fertilizer use was recommended as early as the 1920s, but cheaper fertilizers and agricultural work prompted many farmers to move to uniform farming until the 1980s. Variability in soil fertility was significant, and sampling of a neglected part of the field could be an inaccurate approximation of general fertilizer requirements; later on, this created the theme of grid sampling. Fine grid sampling was carried out in the same area regularly till around 1994. However, until a few decades later, there was little practical implementation of this principle. Figure 10 represents the piezometers data in the Rechna Doab of Pakistan and Interpolation of the this data.

Fig. 10

Interpolation using GIS

13 Yield Monitoring Techniques

The agricultural output varies geographically and temporally due to many limiting factors such as soil type, fertilizer supply, water availability, weather, and crop variety. It’s difficult to evaluate the influence of these limiting limitations on crop yield, as well as the regional variance of crop output before harvest. During the season, the use of remotely sensed aerial images can aid improve estimates of agricultural production. However, the success of such methods is usually decided by the image categorization system utilized.

14 Smart Sensors and IoT Applications

Farming efficiency hinges on a farmer’s capacity to anticipate natural events and respond as promptly as possible. Due to quick data gathering and distribution, the precision of such projections was not as high a few decades ago as it is now. With increasingly complicated Farm Management Information Systems supporting everyday farmers’ decisions, agricultural production management is entering a new era. The latter has evolved from simple record-keeping software to complex systems capable of manipulating large amounts of data and assisting with decision-making. Figure 11 presents the soil moisture sensor, developed under the Students Final Year Project at KFUEIT, Rahim Yar Khan.

Fig. 11

Soil moisture sensor, Students Final Year Project KFUEIT, Rahim Yar Khan

15 Delineation of Management Zones

Local farming has a distinct mindset from land farming. According to soil farming, fertilizer requirements vary by soil type, but are similar within each soil type. Specific tillage suggested that there is a lot of variation across soil chain boundaries, and the only method to figure out how much fertilizer is required is to take grid samples or soil samples at the soil chain boundaries. The advantage of irrigated crops provided for a deep grid soil sample, which could be utilized to define the flexible P and K fertilizer control regions. The maximal grid space of the soil sample can be calculated using geostatistics. Soil parameters, including soil texture and organic matter content, are the most popular ways of classification of management areas, followed by sensitive approaches such as electrical conductivity maps and remote sensing. Crop map layout, followed by height variances throughout the field, are two other unusual ways of characterizing management areas. Similar practices are well applied for the detection of groundwater quality zones for irrigation purposes. The basic parameters of the groundwater irrigation quality are considered SAR, RSC, and EC. These interpolated maps are classified based on the irrigation water quality standard, and then management zones are formulated through the overlay approach in GIS. The figure represents the groundwater quality zones detected using GIS. Figure 12 shows the groundwater quality zones delineated using GIS.

Fig. 12

Groundwater quality zones detected using GIS

16 Introduction to Agricultural Robotics and Unmanned Arial Vehicles

Over the past three decades, precision automated navigation has been one of the most active fields of research and application. This method has the advantages of decreasing user fatigue, eliminating mechanical strains, and increasing fuel efficiency. The mechanized cultivation of circular fields based on the distance to the center using a cable spool method automated the agricultural machinery. The use of radio balloons or microwave signals to automate agricultural machinery areas necessitated a clear line of sight and a significant set of equipment in the area.

GPS is the most prevalent form of precise autonomous navigation. The use of GPS for autonomous tractor steering in straight lines is becoming popular in agriculture practices. The tractor’s steering unit is automatically guided by GPS, which is paving the way for speedier trade and implementation of autosteer technology in agriculture. GPS is utilized to drive the tractor over curved tracks, which is far more difficult than traveling in straight lines. Multiple sensors, such as GPS, geomagnetic directional sensors, and machine vision, are frequently used in recent efforts to improve navigation accuracy. Japan has been a pioneer in the use of all types of autosteering navigation technology, particularly in Hokkaido Island’s tiny agricultural industries. Depending on the investment, automatic tractor rotation can take a variety of forms, including manual lightbar manipulation, and an assisted steering wheel, or autosteer.

17 Conclusion

Precision farming is an emerging field to ensure food security through the methodology of sustainable use of input resources. Precision farming is an art to implement the engineering principles to implement the management decision timely and correctly under a sustainable solution. This chapter provides the insight about the core engineering principles about the precision farming as a route path for the developing countries to ensure the food security while optimizing the resources.