Resumo

CAMPOS MAGANA, Santos Gabriel et al. Development of a soil penetrometer integrated with RTK-GPS technology for generating soil resistance penetration maps. Terra Latinoam [online]. 2015, vol.33, n.2, pp.119-128. ISSN 2395-8030.

Precision agriculture requires accurate information about soil properties to optimize the input supply and to satisfy a particular crop need. In particular, resistance to penetration (RP) is a factor that measures soil compaction, which limits the growth of roots and crop yield, so it is important to determine its magnitude and location. This paper describes the development of a system for measuring and monitoring physical soil properties, specifically an integrated penetrometer with two sensors (resistance and depth) connected to Real Time Kinematics-Geo Positional System for Agriculture (RTK-AgGPS) technology in order to construct soil compacted layers diagnostic maps. The first sensor was developed for RP measurement using a ring transducer with a capacity of up to 9 MPa, a sensitivity of 13.15 Nm V-1 and a correlation coefficient of 99.6% between the applied force and the output voltage. The second sensor was developed to determine with high accuracy the working depth of RP with a maximum displacement of 0.60 m, a sensitivity of 258.5 mm V-1 and a correlation coefficient of 100% between the penetration depth and the voltage output. For field evaluation, the portable sensors carriage prototype was attached to the tractor three-point hitch; the penetrometer is driven by a hydraulic actuator. Systematic sampling with 30 points was performed using RTK-GPS technology to obtain RP values and location with an accuracy of 0.025 m in a working depth range of up to 0.40 m. Three maps were generated with a GIS software for three different ranges of depths: 0.20, 0.30 and 0.40 m.

Palavras-chave : force sensor; position sensor; precision agriculture.