Keywords

1 Introduction

To monitor physical or environmental conditions, such as sound, temperature, vibrations, pollutants or motion and pressure autonomous sensor nodes have been used by wireless sensor networks. All the data collected by the sensor nodes is transmitted to the main base station with the help of network. With the use of these inexpensive, tiny and smarter devices more and more area can easily be covered for the investigation, all measuring environment parameters can be covered. It has enabled the continuous timed monitoring. Now collection of data can be done in real-time. Sensor nodes are used to gather data, store and then sharing the same data on network. As wireless sensor network has a very wide range of applications in almost each and every sector in this article smart agriculture has been focused.

In smart agriculture, precision farming is a technique to manage very large fields. More sophisticated sensor nodes with sensing abilities to biological and chemical parameters are required. This may increase the productivity in the fields and will be helpful for the farmers to achieve more with less efforts [1]. Precision farming is the capacity to deal with so many varieties in the productivity of crops within the fields and to increase it, so that it can help in maximizing the financial properties. This technique is also used to minimize the wastage, environmental impacts by using the automatic data gathering with sensor nodes deployed with in the fields. The gathered information is helpful in managing the fields and decision-making capability also increases. Researchers have introduced so many new and smart technologies in precision farming, few of them are GPS, Remote Sensing and GIS [2]. Whereas to make precision farming more effective characteristics of soil is required. Characteristics’ values may be recorded using sensor nodes which are deployed in the fields. These sensor nodes consist of Sensing unit, Controlling unit and the actuator unit. These sensor nodes are deployed very densely [3] so that the exact and effective data can be collected to address various issues. Sensor nodes do not require any special care, these can be deployed randomly, which means no predetermined position is required. These sensor nodes can easily communicate with each other and are able to transmit the gathered data to the end user or base station. Routing capabilities of the sensor nodes make WSN so important. In wireless sensor networks base station is where user collect the processed and aggregated information. Communication in between sensor nodes and base station can take place using WIFI, Bluetooth and internet connectivity.

This chapter will discuss the possible applications of WSN in smart precision farming which will help the readers to enhance research in this field. The issues and challenges will be discussed and last five to six years of literature will be elaborated to find out current state of art in this research area.

1.1 Wireless Sensor Networks (WSN)

Number of sensor nodes in WSN is much larger than any of traditional wireless networks. A major difference between WSN and other traditional networks computing devices including PC’s, PDA’s and other embedded devices is that in WSN main emphasize is on power management. WSN is a data centric approach but traditional wireless networks are address centric because of large number of nodes in WSN. Sensor nodes are much cheaper than nodes in other wireless networks. WSN uses broadcast communication approach but traditional wireless networks use point-to-point communication. Traditional wireless network like Mobile Ad hoc Networks are designed for distributed computing while WSN are designed to gather information. A unique characteristic of WSN is that data collected by adjacent nodes and some consecutive readings sensed by sensors are highly correlated which gives opportunity to develop efficient protocols. 802.11-like MAC in traditional wireless networks consumes two to six times more energy than S-MAC for traffic load with messages sent every 1–10 s (Fig. 1).

Fig. 1.
figure 1

WSN architecture.

Full size image

In basic architecture of WSN, in sensor unit data gathering and processing operations are completed. All the important and useful data are transmitted to the base station. Transceiver unit is responsible for the reception of the instruction from the base station and to transmit the gathered data to the base station. Power source is the backbone of any device and as in WSN sensor nodes are deployed in an open environment, it is really tough to replace or provide a continuous power supply. There are many solutions to this problem provided in literature like solar power etc. but still the power sources used in sensor nodes are batteries. Analog to digital Converter (ADC), microcontrollers used in WSN, understands binary and some of the analog sensors are used whose outputs are analog and this output needs to be converted to the digital signals. In sensor node GPS is placed which helps to find the location for randomly deployed sensor nodes [4]. Most of the sensor nodes are common to all applications like temperature sensors, humidity sensor etc. otherwise, sensors can be designed according to application requirements. In this chapter sensors available for smart agriculture or used in smart agriculture will be studied. Also, various techniques used in smart agriculture, issues and challenges present in smart agriculture will be discussed.

1.2 Internet of Things (IoT)

Internet of things is a technology which connect physical electronic devices through internet. These devices are capable in gathering and exchanging data (information) over a network as these devices are equipped with unique addressing. IoT is based on embedded system technology as it contains both hardware and software, this allows IoT devices to communicate in both the states (inside and outside environment). IoT is based on three layers system, which are sensing (perception layer), network layer (MAC & Routing) for the data transfer, and application layer related with the output [5, 6]. Internet is used as human to human communication whereas IoT is internet for machine to machine communication. IoT may be used in abundance of applications which includes smart cities, smart buildings, agriculture, defense and healthcare etc. (Fig. 2).

Fig. 2.
figure 2

Architecture of IoT systems.

Full size image

Smart agriculture is one of the most potential area of research and almost whole world is getting influenced by the applications of WSN and IoT solutions for it. These solutions include precision equipment, geo-positioning, actuators, sensors, UAV’s (drones), robotics and automation etc. [7, 8]. IoT offers so many options for smart farming like useful data collection regarding crops and soil, crop control and automatic farming methods. As the sensors used in are capable of providing useful information to the farmers regarding their crops yield process, moisture level, soil nutrition, pest infestation and information regarding above said parameters can be very useful for the farmer to increase his productivity (Fig. 3).

Fig. 3.
figure 3

IoT applications in agriculture industry.

Full size image

2 Literature Study Process

Most of the papers included in this chapter are from last five years, until unless it seems to be important to include some of oldest papers. The research questions are designed, and the relevant research works are referred accordingly.

2.1 Research Questions

The chapter’s main focus is to provide answers to the questions related to use of WSN in smart agriculture. Major research questions that will be answered in this review are:

RQ1.

What are the possibilities to use WSN and IoT in agriculture?

RQ2.

What are newly developed sensors to be used for making smart agriculture a revolution?

RQ3.

What are various issues and challenges researchers may face, when they are working with WSN in agriculture?

2.2 Information Source

Due to wide scope of this book, it was suggested that, different research databases can be extracted for existing work on smart agriculture with WSN. So, in this chapter mainly five databases are considered in searching, to generate the state of the art in use of WSN and IoT with agriculture. These databases are

  1. 1.

    IEEE Xplore (www.ieeexplore.ieee.org)

  2. 2.

    ACM digital library (dl.acm.org)

  3. 3.

    Science direct (www.sciencedirect.com)

  4. 4.

    Google Scholar (www.scholar.google.com)

  5. 5.

    Springer (www.springer.com)

  6. 6.

    Taylor & Francis Online (https://tandfonline.com/)

The papers considered for the review in this chapter are only from high impact research journals and conferences. These articles are indexed in SCI, Scopus and Web of Sciences databases. The searching keywords were related to sensors, WSN, IoT, Precision agriculture, Smart agriculture, Crop management, soil management, monitoring crops, irrigation control and other related words.

3 Review of Literature

This article is concerned about the research in smart agriculture using sensors and IoT, published in reputed journals during last five years. The literature survey includes crop monitoring research, sensors to be used in smart agriculture and communication technologies for smart agriculture. These categories of literature are summarized in upcoming subsections.

3.1 Crop Management with WSN

Agriculture is the backbone for the humans as it is one of the main sources of food. Agriculture has a great role in the growth of countries’ economy. This field offers a huge amount of employment for the people. So, the growth in production of agriculture products is also very important. Traditional methods are still in use and are not so much effective in the productivity of the agriculture output [9]. In order to address all the issues in agriculture it is necessary to introduce automation with the help of WSN and IoT. The table below present some the recent research on crop monitoring technologies using WSN and IoT [10]. In the following table the findings of authors from last five year in the area of crop monitoring are discussed. The papers discussed in the following table are from reputed databases only and also only last three years are considered for this review (Table 1).

Table 1. Crop monitoring research during last three years (2017–2019)
Full size table

3.2 Sensors Used in Smart Agriculture

Sensors/Sensor nodes are compact in size, cheap and easily available. A sensor node mainly consists a microcontroller, transceiver, power source, memory, ADC (analog-to-digital converter) and finally one or more sensors [36]. The microcontroller is the brain of the sensor node which processes all of the data gathered and also controls the functionality of all components mounted on the node. The transceiver transmits the collected data as well as receives the data to and fro from the base station or control section using wireless transmission media like RF (radio frequency), optical communication (laser) and infrared. Sensor nodes produce a measurable response to any physical change that occurs around them. Conditions like temperature, humidity, pressure etc. can be detected by the sensors easily. Following table presents the details about sensors used in various research papers during last five years. From the table one can know the possibility of using sensor nodes and type of microcontrollers in smart agriculture applications (Table 2).

Table 2. Sensors used in research on smart agriculture during last five years (2015–2019).
Full size table

3.3 Potential Area of Applications of WSN and IoT in Agriculture

IoT basic component description is provided in Sect. 2 and it uncovers its extraordinary capacity of dealing with the applications of the agriculture and ongoing patterns of the PA (precision agriculture). Developed IoT devices are of low cost and tiny in size along with daily advancements in sensor technology has contributed in a great manner toward agriculture field [31]. Various types of sensors like radiation, pressure, wind, climate stations, climate sensors, temperature & humidity sensors gives stress to the point that it is all about sensor and sensor information streams, which are deployed to the open environment for observations, sensing, thinking, learning mining, and controlling the devices according to the need. Additionally, recently, there is a growing enthusiasm for high gauge and safe rustic things. This example has yielded the prerequisite for interoperable, flowed, solid, and exact co-appointments conspicuousness structures. The IoT gathering of headways gives all the correct gadgets to building and keeping up such structure and organizations, uncommonly expected to help supply chains in cultivating and floricultural regions [32]. Wired and wireless sensor have been utilized for the agricultural applications in recent decade. Recognizing the earth wherein age occurs, and, even more starting late, the responses of the plants to the air is huge for taking the privilege and continuously accurate decisions, redesigning productivity and nature of the cultivars. The standard WSN have starting late progressed to IoT welcoming Wireless sensor frameworks, by grasping progressively ordinary measures with respect to correspondence, empowering remote access to the web and realizing wise counts for meta-treatment of the data significance to improve checking or conceivably control. Adaptable devices, with high computational limits, favorable structure factor and simplicity, would these days have the option to be used, on batteries, and work for huge parcels, with or without the assistance of force gathering modules. Likewise, at present introduced devices have sufficient resources for help all the more mentioning sensors, for instance, picture sensors, and the assistance of continuously propelled frameworks organization shows, such TCP/IP, growing the standard WSN arranging capacities. A terrible portrayal of composing on checking and control could be Monitoring and, at times, creation of early cautions, by methods for streamlined rules. This fuses multi-point checking for getting and immersing climatic slants in nursery advancement [33] Detecting is of high centrality in agriculture. WSNs have been commonly used in air and soil checking associations both in open field and in controlled condition cultivation. Controlled condition agribusiness Greenhouses have been seemed to show colossal climate vacillation, which impacts the proficiency of the plants. Nursery improvement is dynamically outrageous, in like manner, when in doubt, it requires higher exactness to the extent watching and control a few assessments have concentrated just on confined and remote checking. A great part of the time, data is taken care of and addressed in various graphical ways [32]. Despite the high-exactness checking, there have been studies presenting structures which circuit meta-getting ready strategies with data proceeded onward remote establishments through the web. Utilizing outstandingly surveyed conditions, yield and climate models, such structures produce assessments of the environment just as reap status all together for the cultivator to settle on better decisions or get early alarms [33].

3.4 Challenges in Smart Agriculture

Adoption, utility and applications [34] of WSN and IoT in agriculture is not without multitude of challenges and the requirement of addressing difficult research problems. Some of the challenges researchers may face during their research in smart agriculture are discussed in following subsections. These challenges may also act as future perspective for research in precision agriculture using WSN and IoT.

3.4.1 Data Analysis

Data science becomes the most important and popular field of research in computer science. Data analysis is very important in almost all of the applications of WSN and IoT. The decision made by the users, while applying WSN to certain applications, depend on the data collected by the sensors. The challenges in smart agriculture also include this problem [37]. The issue impose problem of integration of sensor nodes to analytic application which can further make decisions or drive automation activities. If integration is successful than it will be cost effective for the farmers and may contribute to increase the production.

3.4.2 Hardware Systems

WSN and IoT in smart agriculture faces many difficulties. The foremost problem is living the hardware in the open environment and expect it to work in harsh environmental conditions also. These harsh conditions may harm the normal embedded systems which expose it’s electronic components to the open conditions like high sunlight based radiation, outrageous temperatures, downpour or high dampness, solid breezes, vibrations and different risk. These conditions may damage the electronic circuits inside the devices [38]. The end-gadget ought to stay dynamic and limit trustworthy for huge misfortunes relying upon the compelled influence resources of batteries. Along these lines, appropriate programming instruments and low-control capacities are required, since the progressive battery substitution or reset of the stations, for example in a large-scale open field course of action, isn’t straightforward.

3.4.3 Security Issues

Like any other industry, ranchers need to think about security and safety of the technology used by him in proper manner. The PA concept brings the agribusiness into the risk of data theft and hacking. Moreover, ranchers do not have proper knowledge of data protection in this field [39]. Developers of IoT devices uses IoT devices to collect the information and data analysis to make agriculture practices more efficient. However, ranchers are still using traditional methods for agriculture which do not have data security concept.

3.4.4 Networking Challenges

Odd situations of the nature offer great difficulties to the equipment, and to the system layer. Remote communication is used in the field of agriculture to overcome the cost of the wires which are used in wired devices [40]. Nature is known to be one of the fundamental contemplations which lead to low remote association quality, through the multi-way multiplication effects and its promise to establishment uproar Real-world game plans, has shown that the presentation of standard handsets is affected by temperature sogginess human closeness and various preventions inside the space in which a remote center point attempts to pass on. According to this information collected by the sensor can be transferred with the utilizations of the powerful and dependable enhancement done in technological development as per the challenges and requirement of the rustic conditions [35].

Despite of above challenges nowadays, many manufacturers of farm gadgets provides complete solutions in integration with IoT devices. In their business it plays vital role. As these Precision agriculture solutions provides ranchers a huge set of data to enhance their farming and knowledge by gathering real-time data. As these devices are this much important these devices should have capabilities for data storage, security, deep analytics and device management on the data received from the remote sensing techniques, on-field deployed sensors and images from drones. This will generate data to educate farmers and scientist with capabilities of better decision-making.

4 Conclusions

Internet of things involving agricultural machinery, can be utilized to manage standard farming fields, whereas ranchers still needs to play the role of both scientist and the person to keep an eye for unforeseen situations. Farmers can feel relaxed by investing in digitalization treatment of the plant diseases and monitoring the livestock. New ITC devices can be useful in tackling crop diseases and pest controls. As there is a lack of knowledge about these ITC devices in farmers. Agriculture industries still needs to convince ranchers towards the benefits of these technological advancements of IoTs. Internet of Things provides farmers a platform to exchange information and establish connections and cooperation’s. This can further be important that they may develop an informal communication system which can play a vital role in advancing the formal communication system.