Evaluation of the physical conditions of chernozem soil by using penetrometer in a long-term tillage experiment

Similarly to other soil physical parameters, the high standard deviation of values is typical of the soil penetration resistance measured by static penetrometer also in case when the measurement points are relatively closely located to each other. Following mathematical and statistical methods, it is possible to determine the smallest number of replications, by which the estimation error of measurement can be pressed under the acceptable value. The penetrometer is more sensible to a change in the bulk density of dry soil than it is in the case of wet soil. Long-term tillage management without deep tillage, especially shallow spring disk tillage, on chernozem soil caused soil compaction under the tillage layer. Our research results have shown that the formation of adversely compacted soil layers can be prevented by keeping the optimal cultivation moisture, by decreasing the number of passes and by changing the depth of tillage.