Abstract-One of the soil conditions that affect the development of a plant and crop production is the soil moisture. Therefore, it is necessary to monitor this property with multi points and real time of observation around the plant environment. In this research, it had been designed and tested a multichannel soil moisture measurement system with the wireless communication system. The system consists of transmitter and receiver blocks using soil moisture sensors as a soil moisture detector and microcontroller media in both blocks as the overall control of the measurement system. The measured result data is observed directly through the PC display. Laboratory scale testing is done as calibration process of the output voltage from sensor to soil moisture. The soil moisture 14.45 %; 19.92% and 26.73% comparable to 4.71 volt; 4.13 volt and 3.06 volt output voltage respectively. While the resistance values of each humidity were equal to 170.87 kΩ; 49.49 kΩ and 16.36 kΩ. The whole system test is done in the field (oil palm plantation ) with the result obtained that the content of water contented which is pretty much found at the top near the rooting of fibers and the bottom (subsoil).

Data on aquifer characteristic is an important factor in studying groundwater, especially to determine the capacity of groundwater, which can be stored in the soil layer and how much that can be utilized. Geoelectrical survey was applied to observed groundwater at oil palm plantation. The research was conducted in PT. Bio Nusantara oil palm plantation, Bengkulu Province, Indonesia especially at 2, 4, 7, 14 and 22 years of mature plant age (TM). As a comparison for the mature plant age level, the survey was also performed at the oil palm plantation farm-soccer field, oil palm plantation farm-residential and oil palm plantation farm-secondary forest. The result of electric survey on TM2 and TM4 showed some rocks, clay and dry litter still existed. While at the depth over than 4 m was dominated by a shallow aquifer. The dry zone wasn't found at site of TM7, TM14 and TM22, all sites was in high soil humidity. The electric survey result at oil palm plantation farm-soccer field indicated that able to maintain the balance of soil-water availability, there is a shallow aquifer zone at the residential site and a water scarcity at secondary forest site.