No abstract

No abstract

No abstract

This article describes the results of the analysis of correlation between the soil electrical conductivity and BPEJ (valued soil-ecological units). The measurements were made in 2006 at the School Agribusiness Land Farm in Lány established by the Czech University of Life Sciences in Prague. The soil electrical conductivity (EC) was measured by the contact method using a sensor with six electrodes. The soil EC data measured were compared with the data obtained from BPEJ maps. The aim was to verify if any relationship exists between the soil EC and BPEJ. The results achieved show that the same dependency exists between the values of the main soil unit of the BPEJ code and the soil EC. The results achieved can be used in the precise agriculture system to improve the decision process. 131and distribute water and also the nutrients near the plants root system. The soil EC is also significantly influenced by the actual soil humidity but, as states Farahani (2007), "Soil water has a strong effect on the values of soil EC, but research shows that even though the values of soil EC may change as soil water changes, the patterns of a soil EC map stay unchanged. Thus, a single soil EC map for a field is probably sufficient for many years to characterize the soil variability patterns. " Doerge et al. (2007) states that the main factors influencing the values of soil EC are pore continuity, water content, salinity level, cation exchange kapacity, and soil depth. MATERIAL AND METHODSIn 2006, the soil EC measurements were made on the selected land "NS KONOPAS A 6001_3" of the School Agribusiness Land in Lány. The contact method was used for the soil EC measurement by means of a traktor-carried measuring frame with six electrodes (Figure 1). The measuring instrument was developed by the Department of Machinery Application, Faculty of Engineering of the Czech University of Life Sciences in Prague. This equipment provides the soil EC values into a measuring central, incl. the position data, in 5 seconds intervals. The position data were obtained by using the GPS unit. The data chains are stored into the .txt format. The BPEJ data were bought in the digital form by the Research Institute for Soil and Water Conservation, Prague-Zbraslav. The ArcView 9.1 software with Geostatistic and Spatial analyst add-in was used for the processing. RESULTS AND DISCUSSIONTwo data sets were used for the analysis, namely soil EC and BPEJ values. Several modifications were performed on the initial data set prior to statistical processing and evaluation. Before the proper elaboration, the voltage and electrical current data, measured by the measuring central, were re-calculated to the soil EC values. Non-complete records were deleted from the basic file, same as the records containing zeros and extreme values. The file modified in this way was then processed by the procedure described in (Thylén et al. 1997;Kumhála et al. 2001). As both authors identically mention, the most failures occur at the moment of driving the machine into a new row,...

No abstract