P.Yankov
Abstract. The capillary water is of major importance for the growth, development and productivity of plants. The use of different ways of soil tillage affects the natural position and entity of the soil layer, which, on its side, causes variations in the capillary rise of the water. The investigation on the variation of the capillary rise of water in the slightly leached chernozems in Dobrudzha region under the effect of the long-term application of some soil tillage practices was carried out during 2008 – 2010 in the trial field of Dobrudzha Agricultural Institute. Twenty-four soil tillage systems based on different soil tillage tools and operations were tested in a stationary field trial. In this analysis the following variants of main soil tillage were used: plowing at 24–26 cm (check); cutting at 24–26 cm; double cutting at 10–12 cm; direct sowing – pre-sowing treatment of the area with total herbicide. The reading of the capillary rise of water in undisturbed soil condition in the 0–10, 10–20 and 20–30 cm layers was done under laboratory conditions. Total porosity was determined by the values of bulk density and relative weight every 10 cm to depth of 30 cm.The capillary rise of water in the soils with minimal and no tillage was higher in comparison to the soils subjected to intensive tillage. The independent application of plowing reduced the capillary rise of water in the slightly leached chernozem soils. The highest weight coefficients with regard to capillary rise of water were determined in the 10–20 and 20–30 cm layers. In these layers after minimal and no tillage the system of capillary pores and the network of inter-aggregate cavities formed by the roots of the plants remained intact in soil and hence the capillary rise of water was higher. After plowing the large-sized structural soil units along the entire profile of the cultivated layer increased the cavities of non-capillary origin.