EFFECT OF DIFFERENT TILLAGE METHODS ON NUTRIENTS DYNAMICS IN SOILS AND PRODUCTIVITY OF WINTER WHEAT UNDER DIFFERENT ENVIRONMENTAL CONDITIONS
Studying the effect of soil tillage methods on the nutrients dynamics under winter wheat makes it possible to regulate the nutritional regime of plants that affect the crops productivity. Field experiments were carried out in the conditions of plain and foothill zones on meadow-chestnut soil of Gunibsky district and dark-chestnut soil of Sergokalinsky district in Dagestan during 2010-2015. Two-layer and three-layer tillage greatly affected the content of hydrolyzed nitrogen compared to plowing. The content of P2O5 in the soil when plowing in the plain area (average for 3 years) was 2,1 mg for stubble forecrop and 1,9 mg for cultivated, and during two-layer tillage - 2,20 and 2,13 mg, three-layer - 2,41 and 2,31 mg/100 g soil. The content К2О in the soil of the plain area when plowing in the early growing season was the forecrops - 36,7 mg and 32,4 mg and to harvesting: 31,6 and 27,5 mg (control), when two-layer tillage - 30,8 and 28,0 mg and three-layer - 31,1 and 28,2 mg/100 g soil. Similar results were recorded in the foothills zone. At the same time the grain yield when two-layer and three-layer tillage were higher in the plain zone after stubble forecrops - by 0,74 and 1,29 tons or 20,4 and 35,6%, cultivated - by 0,85 and 1,17 tons or 24,5 and 33,8%, and in the foothill zone - by 0,85 and 1,44 tons as well as 0,75 and 1,5 t/ha respectively, compared to plowing.