The objective of the research is to study the influence of different methods of soil primary tillage on water-physical features of soil and potato yield under irrigation. The research was carried out in 2011-2013 in the farm “Semikarakoskoye” of the Rostov region. Experimental plot soil was ordinary chernozem with heavy clay texture. The preirrigation threshold of soil moisture was maintained at the level of 75-80 % FC in 0.6 m soil layer. The background of fertilizers was N120Ð90Ê60 kg of active substance per hectare. There were three methods for soil primary tillage: moldboard, subsurface to the depth of 25-27 cm, and minimum (disking to the depth of 14-16 cm). On the base of experimental data it was established that moldboard and subsurface tillage provided equal change of water-phisical features of chernozem and potato yield 24.79 and 23.13 t/ha (LSD05= 2.34 t/ha), respectively. Against the background of subsurface tillage it was marked some yield decrease comparing with moldboard tillage (by 6.7 %). Water consumption of potato was 3258 m³/ha for moldboard, 3270 m³/ha for subsurface, and 3277 m³/ha for minimal tillage. The most rational use of moisture was at the background of moldboard tillage where the least coefficient of water consumption, 131 t/m³, was observed, but energy costs for subsurface tillage were less by 218 MJ/ha than for moldboard tillage. Against the background of subsurface tillage the best indices of soil bulk density, content of agronomically valuable soil aggregates, and hygroscopicity were observed while energy costs were less by 218 MJ/ha. Therefore, we recommend subsurface tillage to the depth of 25-27 cm along with moldboard tillage for potato.
Keywords: potato, moldboard tillage, subsurface tillage, minimum tillage, soil bulk density, water resistance, hygroscopicity, crop yield, coefficient of water consumption.
