SOIL MOISTURE AVAILABILITY IN AN ORCHARD AND THE NEED FOR ITSREGULATION
The growth and fruiting of fruit crops is interconnected with the biotic and abiotic conditions of the natural envi-ronment as water, heat and nutritional regimes in the soil which continuously change in space and time. The main limiting factor in the forest-steppe zone of the Altai Region is the moisture content in the soil profile since plants often suffer from moisture deficit. The available soil moisture (ASM) storage in the apple orchard in April 2012 was satis-factory. In Mayand in the summer, they dropped to zero, so the plants suffered from water hunger during the grow-ing season. Under pears, at the beginning of the growing season, the ASM turned out to be higher than under the apple trees, but from June to August they alsodecreased. As a result, the irrigation rates were the same as for the apple trees. The summer of 2013 was rainy and that af-fected the water resources in the chernozem layer. At the same time, the ASM deficit did not exceed 85 mm in June and July, and in the remaining periods did not rise above 50 mm. In the pear orchard, the moisture storage did not fall below 30 mm. In one-meter chernozem layer in April 2012, the available soil moisture storage under the apple trees corresponded to a very good level. In June and July, the moisture content dropped below the wilting moisture. In spring, the ASM under the pear plantations were consid-ered satisfactory. On the following months, a severe mois-ture deficit arose until autumn. In 2013, the ASM in the apple orchard did not exceed 50 mm in summer. Under the pears, in May they even reached 118 mm, but then dropped to 30 mm and that also required irrigation. Since the season of 2014 was an arid one, the water situation in one-meter layer of chernozem turned out to be disastrous.