“…The soil penetration resistance was studied in the field environment to a depth of up to 50 at 5 cm intervals. A hand penetrometer Eijkelkamp was used in the study (Medvedev, 2009;Medina et al, 2012;Zhukov, Zadorozhnaya, 2016, 2017Zadorozhnaya, 2018). The average error of the measurement results of the device is ± 8%.…”