Remote intelligent management system for soil sampling based on 3S, ZigBee and radio frequency identification

Abstract: In order to realize intelligent management of soil sampling in farmland, remote intelligent management system of soil sampling was designed based on the technologies including 3S (GIS, geographic information system; GPS, global positioning system; RS, remote sensing), ZigBee wireless communication, RFID (Radio frequency identification), the 4G (4th generation) communication system, and so on. The system consists of acquisition node, gateway of the coordinator, mobile terminal and remote management software. The acquisition node can obtain the geographic location information of soil samples, the RFID electronic tag and the temperature and humidity of the soil environment; key technologies used in acquisition node are ZigBee wireless communication protocol, serial port communication protocol, and modules of data parsing, packaging, sending, and so on. The gateway of the coordinator is constituted by ZigBee coordinator and 4G module, realizing data transformation from the ZigBee wireless network to 4G network. And the data of acquisition node would be transmitted to management software of remote server when the 4G DTU (data transfer unit) was configured with server IP (Internet Protocol), port number and other configuration information. PDA (personal digital assistant) is used as mobile terminal, which has been remodeled by embedding a micro ZigBee coordinator and a management software in the system. So it is convenient and portable to achieve monitoring and controlling of soil samples collection in time for user, and another important function of PDA is it can realize the transformation of the data from soil samples acquisition node to remote server management software through GSM/GPRS (Global System for Mobile communication / General Packet Radio Service) network if there is no 4G network in remote farmland area. The 4G network is primary communication means under normal circumstances because of its higher efficiency and reliability. Therefore, this method can enhance reliability of the whole system with the double communication links. Management software of remote server develops the data reception, Baidu map, automatic data mapping (two-dimensional, three-dimensional) and other function modules based on Web, SQL (structured query language) Server, Socket and other technologies. Data will be saved to different groups for each test in data reception module, so it is convenient to process data for user. The real-time tracking of soil sampling can be realized through Baidu map with latitude and longitude information from GPS module, and the spatial distribution figure of soil sampling can be automatically generated by calling data collected in database or uploading the local experiment data. We can use system to collect soil sample information and obtain according total nitrogen content of soil sample in laboratory at the same time. In this way, total nitrogen content data of soil sample were imported into information bar by corresponding RFID label in soil management software, generating spatial distribution figure of soil nitrogen, which will provide the decision support for subsequent variable fertilization. The stability test of the system shows it has a high reliability, the packet loss rate of which is 0.2%. So the remote intelligent management system for soil sampling can work stably and accurately, and can be used in production practice. With the further study of the system, it will continue to be improved. The next step will be to increase the number of ZigBee acquisition nodes, and sensor is integrated with different functions of field information detection.