814 Soil Parameters Assessment by Remote Sensing Theofanis A. Gemtos 1 , Christos Cavalaris 2 , Christos Caramoutis 2 , Dimitris Anagnostopoulos 2 , Stavros Giouvanidis 2 , Spyros Fountas 2 1 Laboratory of Farm Mechanisation, University of Thessaly, Fytoko Street, N. Ionia, 38446 Mangesia, Greece, +30.2421093228, gemtos@agr.uth.gr 2 Laboratory of Farm Mechanisation, University of Thessaly, Fytoko Street, N. Ionia, 38446 Mangesia, Greece Abstract. In this paper, remote sensing measurements like apparent electrical conductivity (ECa.) are used to assess soil compaction. In an experiment comparing five tillage treatments and their effect to energy crops soil penetration resistance (SPR) was measured at the same time as ECa. ECa measurements were carried out using EM-38with dipoles at 1m apart and SPR by an electronic penetrometer. The negative correlation between the two parameters for all measurements resulted in R2= 0.73. Taking the measurements for each treatment in conventional tillage plots R2 = 0.53, chisel plough tillage 0.61, rotary tiller 0.69, disk harrow 0.55, strip-till 0.35 and no till 0.81. Keywords: soil compaction, tillage, soil apparent electrical conductivity, soil penetration resistance 1 Introduction Soil compaction is a major problem of soil degradation affecting soil fertility and crop yields. Soil compaction is caused in the present day agriculture mainly by heavy farm machinery. Several factors affect compaction by machinery like soil water content, machinery weight, machinery tyres (width, type and inflation pressure). Compaction is not homogeneous in all parts of the field because it depends on the traffic of each part. The compaction caused is alleviated by soil tillage. Soil deep loosening causes breaking of the soil causing the restoration of large pores and facilitates the soil functioning. Tillage practices employing deep loosening and soil inversion like conventional tillage using ploughing or minimum tillage that causes soil loosening at different depths without soil inversion can lead to higher or lower soil disturbance and loosening. Soil tillage is an energy and labour consuming practice and the intensity depends on the soil compaction. It would be of interest to find ways to assess soil compaction in order to apply variable rate tillage depth and reduce energy consumption. Soil compaction is measured by instruments like penetrometers measuring soil penetration resistance (SPR) at different depths, by measuring dry bulk density at layers of different depths and by measuring water infiltration rate. Penetrometers are