ORAL - International Conference of Agricultural Engineering

AbstractA Wireless Sensor Network for Precise Soil WaterManagement in an OrchardTakashi Togami 1 , Kyosuke Yamamoto 2 , Ryoei Ito 1 , Atsushi Hashimoto 1Takaharu Kameoka 1 *1 Mie Univeristy, 1577 Kurima-machiyacho, Tsu, Mie, 514-8507 Japan2 The Univeristy of Tokyo, 1-1-1 Yayoi, Bunkyo, Tokyo, 113-8657 Japan*Corresponding author. E-mail: kameoka@mie-u.ac.jpThe importance in field sensing and plant sensing including data measurement and collectionof agrometeorological and micrometeorological data of the target field and plant informationhas been dramatically increasing in order to cultivate crops with required quality by optimalcultivation management or smart farming such as irrigation control. Field Server and weatherstation of eKo collect field representative value such as ambient temperature, humidity,amount of sunlight and precipitation, while sensors attached to each sensor node acquire theproperty value including soil information. It was decided to set up sensor nodes at threecritical points where it becomes irrigation index for the cultivation management, and thepoints were selected according to the soil moisture distribution map based on the researchon Time Domain Reflectrometry (TDR) soil moisture measurements of orchards. Toaccomplish our goals, we installed a wireless sensor network to support long-term, stableoperation, including optimal placement of sensor nodes, optimal installation of the sensorsand modification of network connections with Internet, and developed user-friendly FieldServer and eKo data browsing software to support agricultural workers.Key words: A wireless sensor network, Smart farming, Field sensing, Plant sensing, FieldServer1. IntroductionSatsuma Mandarin cultivated in Nanki, Mie, Japan is one of the most excellent rareripes.However, lack of agricultural continuators makes the translation of special agricultural skillsmuch harder. Furthermore both external and internal qualities of fruits in pomiculture havebeen required in Japanese market since the adoption of marketing strategy such as fruitsorting by optical sensors, and a segregation strategy. Hence, the importance in field sensingincluding data measurement and collection of agrometeorological and micrometeorologicaldata of the target field and plant information has been dramatically increasing in order tocultivate crops with required quality by optimal cultivation management or smart farming suchas irrigation control (Togami et al., 2010a).We introduced an agricultural small stationary robot, Field Server (Fukatsu et al., 2005),which measures environmental and growing conditions in real time in the orchard, and Mulchand Driptube system, which produce high quality fruit with being unaffected by weather, as isshown in Fig. 1 (Fujita et al., 2011; Togami et al., 2011a).The aims of this study are to install a wireless sensor network to support long-term, stableoperation, including optimal placement of sensor nodes, optimal installation of the soilmoisture sensors and modification of network connections with Internet, and to develop userfriendlyField Server and eKo data browsing software to support agricultural workers.2. Experimental Setup and Method2.1. Soil Moisture Content Distribution