EVALUATION OF THE GROWING CONDITIONS OF SEA-BUCKTHORN PLANTATIONS UNDER INUNDATIVE IRRIGATION
Sea-buckthorn grows well on slope lands that are highly drained and lack stagnant water. The optimum soil moisture content for sea-buckthorn corresponds to 70% of the lowest moisture capacity. Under continuous soil moisture deficit, the leaf surface area decreased, the fruits were poorly set as a result of ovary drop during the first half of the growing season, and berry size decreased. In this regard, the study of the water regime of the soil under sea-buckthorn plantations the possibility of its regulation remained quite topical. The available moisture in the humus horizons of chernozem in May 2004 corresponded to a satisfactory level. At the end of summer, the moisture content of the chernozem decreased to unsatisfactory state. As a result, the plants experienced water deprivation throughout the growing season. Naturally, the need arose for irrigation, especially in June and August with irrigation rates of 490 and 280 t per m3, respectively. In the underlying horizons, the soil moisture deficit was weaker. In the humus horizons, the available moisture in the chernozem in the middle of the slope did not differ much from the moisture content at its top. At the same time, in the transitional BC layer in the second half of summer, the available moisture content was significantly higher. This difference was also found in the parent rock. In the lower part of the slope, the one-meter soil layer contained a greater amount of moisture which contributed to the decrease of its deficit during the entire growing season. This was especially noticeable in the illuvial horizon and parent rock. In the second half of summer, the available moisture content here remained higher than in the upper slope sites. In conclusion, it should be noted that only humus-accumulative horizons A (arable) + AB needed irrigation with different irrigation rates depending on the location of the sea-buckthorn plantations on the slope and their growth features.