Abstract Agriculture is a source of livelihood of majority Indians and has great impact on the economy of the country. In a country like India, where climatic conditions vary substantially and irrigation facilities are poor, sustainable agriculture practices that conserve resources and make a farmer’s life easier are absolutely essential. This paper proposes a system that makes use of contemporary technologies- wireless sensor networks, GSM and SMS – to provide the farmer with the ability to handle the water level in the field remotely and in real time. Keywords Wireless Sensor Networks, GSM, SMS, Sprinkler, Agriculture, India, Mobile I. Introduction Even in the modern era of industrialization, agriculture plays a very significant role in the overall socio-economic development of India. India has an agriculture based economy. 43% of India’s territory comes under agricultural lands. Agriculture along with other related fields like forestry and logging provides employment to 52% of India’s population.
Agriculture also accounts for 8.56% of the country’s total exports. According to a survey made in 2007, agriculture accounts for 16.6% of India’s Gross Domestic Product . Hence, it is agriculture that is the most influential field as compared to others in India. This importance on agriculture leads to an emphasis on better agricultural practices. Sustainable agricultural practices that lead to better development of the crop and better utilization of resources are required in order to meet the changing needs of the people and economy and also to maintain the environmental balance.
This paper proposes one such method that makes use of wireless sensor networks and mobile phone to control the water level in agricultural fields remotely. Minimal power consumption can be achieved for the watering process along with optimal water usage. Due to the fast development in tele-communication technologies, it is believed that wireless communication is a good practice for remote sensing in the agriculture industries. This system has fully utilized wireless sensor network, Global System for Mobile Communication (GSM) and short message service (SMS) to carry out data from the sensors to computers or directly alert the workers through their mobile phone and to control the watering process, also through the mobile phone. This practice eliminates the use of wired technology, improves old method of collecting data in farming areas and allows farmers to control their sprinklers remotely.
II. Design of the system
Fig. 1: Basic Outline of the proposed system The basic objective of this system is to utilize the wireless sensor network to collect real-time status of the agricultural field and to use the mobile phone to control the watering of the field. The wireless sensor nodes are placed at strategic points in the fields. These nodes collect information regarding the condition of water level in the field and send this data to a central sink node. The sink node processes this information and sends it to the user’s mobile phone. The user can then view this information and can adjust the watering of the field by controlling the sprinklers through the sprinkler controller. The major tasks of the system that this paper deals with are A. Finding the best method to arrange the nodes of the wireless sensor network in the field. B. Sending the information collected in the sink node to the user’s mobile device. C. Controlling the sprinklers, using the mobile, to maintain the water level in the field.
III. Arranging the Nodes The nodes make up the wireless sensor network. Each of these nodes contains – a sensor, a radio transceiver, a battery and an interfacing circuit. The placement of these nodes in the agricultural field is essential to obtain an efficient system. Irregular placement, without any concern for the physical conditions, can lead to a system that is highly faulty and does not serve its cause. The placement of the nodes in the agricultural field will majorly depend on the following conditions – A. Area and Shape of the agricultural field – based on the area and shape of the field, the divisions of the field are made and the number of nodes required can be calculated. B. Division of the field – the way in which the field is divided will influence the positioning of the nodes of the wireless sensor network.
C. Topography of the divisions – the varying level of the field plays an important role in determining the positions for InternatIonal Journal of Computer SCIenCe & teChnology the nodes. The type of sensors used in the nodes is equally important. Level sensors can be used to measure the water level in the soil. However, level sensors have the drawback that they do not take physical conditions into account – the entire field may not be on the same level, different types of soil need different levels of water, etc. These drawbacks of the level sensors can be overcome by the use of soil moisture sensors such as DT171A (Ref: ) etc., These soil moisture sensors work using the fact that capacitance in water is greater than the capacitance in the soil. Hence these soil moisture sensors can produce better results than level sensors.
Table 1: Ref  Comparision between major technologies
Technology Range Data Rate Media Security GSM Wide 9.6 Kbps Suitable and Low Cost Moderate Blue-tooth Short 700 Kbps Need access point to send to distant places Moderate 3G Limited 2 Mbps Costly for sending text messages Moderate
Store and-forward capability which, in the case the host server is out of service, allows the user to still gain information after the problem is fixed.(Ref: [5, 7] The use of mobile phone in this operation will result in a significant cost and time saving as well as the user would benefit from being able to use familiar gadget. The SMS technology provides an efficient information delivery service to the users. According to an experiment conducted by , the SMS transmission can be found to be highly reliable. The following is a table depicting the results of the experiment – Table 2: Ref:  Results determining the reliability of SMS technology
Fig. 2: (Ref: ): A Soil Moisture Sensor The sensitivity of these sensors will depend on the type of soil that is used in the field. Some types of soil absorb more water than others and hence the sensitivity of the sensors that are used must vary. So far, systems that use wired devices have been used to implement such agricultural practices. These systems are constrained because of their lack of mobility, complexity and unsuitability to adverse conditions. Wireless sensor network technologies have enabled sensor nodes to be deployed in quantity to gather environmental parameters and to detect certain events by using inexpensive microcontrollers and lowcost RF hardware (Ref: ). These wireless systems are highly reliable under adverse conditions also. This paper presents a system that is completely un-wired- it uses only wireless transmission of data to perform its functionality.
IV. Transfer of Information The next step, after collecting information regarding the status of water level in the field, is to transmit this data to a central node called the sink. This paper proposes the use of GSM and SMS technologies in order to perform this transfer. Once the sink receives data from all the nodes, it develops a database to organize the data and then an SMS will be triggered and sent via GSM modem through the cellular network to the farmer’s mobile phone. GSM and SMS solutions would provide benefits which include among others – 1. Simple power solutions 2. Wide range of coverage – GSM technology has a wide range of coverage and provides advantages over other faster, but less effective technologies. The following table shows a comparision between the three major technologies –
Accuracy of data
Total Data Transmitted 915/ 915 25/915 6/915
Percentage Value 100 % 2.73 % 0.66 %
Transmission Retransmission Total data rate loss
V. Controlling the Sprinklers The final process of the system is to allow the user to control the sprinklers present in the field remotely through his mobile. Here, two major conditions must be taken into account – the type of sprinklers used in the field and the method to control these sprinklers. Existing systems span the evolution of technology from water to electric and hydraulically driven machines. According to , center pivot sprinklers are operating on varying topography, and also take into account the soil texture and other parameters. Low infiltration rate soils challenge managers of standard machines with the need to provide little or no irrigation water to some areas while fully irrigating others.
All these factors represent a reason for using some sort of monitor/controller to manage water applications based upon need. This system proposes the use of sprinklers that have 2 major features – pulsing and nozzle orifice control (Ref ). Pulsing is a method by which the water application depth can be controlled by a series of on-off cycles. Reducing the on-time is effective at reducing both the application depth and the water application rate. Nozzle Orifice control indicates that the sprinkler uses a mechanically-activated pin to alter the nozzle orifice area which adjusts the sprinkler flow rate over the range of 35 to 100% of its rated flow rate based upon operating pressure. The pin can be controlled using either electric or hydraulic actuators. These features allow the sprinklers to control the direction, amount and rate of water to be distributed. w w w. i j c s t. c o m
InternatIonal Journal of Computer SCIenCe & teChnology
ISSN : 0976-8491(Online) | ISSN : 2229-4333(Print)
IJCST Vol. 2, ISSue 4, oCT. – DeC. 2011
Controlling the sprinklers is done by means of using a special device called the sprinkler controller. This controller consists of a GSM modem and a microcontroller that is programmed as per the requirements. This controller receives command from the user’s mobile phone through the GSM modem and the micro-controller performs the necessary control operations as per the command received. The basic technique used to interface the mobile phone to the sprinkler controller is the missed call instruction format. In this technique, the user is required to make a certain number of missed calls within a specified period of time. Each number of missed calls is associated with a certain instruction that has to be performed. Once the user has made the required number of calls, all the microcontroller has to do is count the number of missed calls, check the pre-defined table embedded in it and then perform the associated instruction.
A sample table that is pre-defined in the controller may be as follows – Table 3: Example for Missed Call Instruction Format % Nozzle Orifice area to be opened 2 25% 30% 3 50% 60% 4 65% 45% 5 100% 50% This approach, however, has some drawbacks. The number of instructions will become limited. This is because the number of missed calls that a user can make in a certain amount of time is limited. So, a more efficient, but more complicated one is the use of SMS technology. Using this, the user can not only have a large set of instructions but can also control each sprinkler individually. Here, the user sends an SMS in a fixed format – the sprinkler ID (in order to controller individual sprinklers), pulsing rate and percentage nozzle orifice area to be exposed. An example SMS can be as follows – No. of Missed Calls Pulsing Rate 1- 25+30, 2-50+60, 3-65+45/ Fig. 3: Example of SMS sent to the controller
The first line indicates that the sprinkler with ID number 1 has to be operated at a pulsing rate of 25 (i.e. on for 25% of a minute and off for the remaining time) and with 30% of nozzle orifice area being exposed. The instruction for each sprinkler can be separated by a comma (,) and ‘/’ is used to indicate the end of the instructions. The controller retrieves this information from the SMS, and sends control signals as per the instructions in it. This technology can be extended to help even illiterate farmers by making use of voice messaging technique. VI. Conclusion The need for systems that make agriculture easier and more sustainable has increased within the past few years. The ability to conserve two of the most important resources of a farmer, water and time, has been the latest challenge. A w w w. i j c s t. c o m system that provides this ability – through the use of efficient and reliable methods such as wireless sensor networking, sprinkler irrigation, GSM, SMS technologies and readily available mobile phone devices – is certain to help the farmers get a better yield and on a larger scale, help the agricultural and economic growth of the country.
 William L. Kranz, Robert J. Evans, Freddie R. Lamm, Susan A. O’Shaughnessy, Troy G. Peters, “A Review of Center Pivot Irrigation Control and Automation Technologies”. Paper Number: IRR10-9632. ASABE conference. 2010  Mahir Dursun, Semih Ozden, “ A wireless application of drip irrigation automation supported by soil moisture sensors”. pp – 1573-1582. 2011  Xihai Zhang, Junlong Fang, Xiao Yu,“Design and Implementation of Nodes Based on CC2430 for the Agricultural Information Wireless Monitoring”, IEEE. 2010  Eng Jiang, Hongbo Xia, Zhiye He, Zheming Wang,“Design of a Water Environment Monitoring System Based on Wireless Sensor Networks”, 2009.  Vasif Ahmed, Siddharth A Ladhake,“Design of Ultra Low Cost Cell Phone Based Embedded System for Irrigation”, IEEE, 2010.  [Online] Available: www.wikipedia.com  Izzatdin Abdul Aziz, Mohd. Hilmi Hasan, Mohd. Jimmy Ismail, Mazlina Mehat, Nazleeni Samiha haron, “Remote Monitoring in Agricultural Greenhouse using Wireless Sensor and Short Message Service(SMS)”, International Journal of Enfineering and technology IJET Vol,9 No. 9.  [Online] Available: www.howstuffworks.com
InternatIonal Journal of Computer SCIenCe & teChnology