The aim of the research is to identify an optimal combination of irrigation regime, method of tillage, and mineral nutrition level for pumpkin (Cucurbita moschata) growing. The experiment was conducted in the Rostov region in 2012–2013. We studied three variants of irrigation regime: intense (pre-irrigation threshold of soil moisture content 75–80 % FC in soil layer of 0.6 m throughout the growing period), water-saving (irrigation in the period from seedling emergence till flowering) and rainfed. Background of mineral nutrition was as follows: recommended fertilizer dose P90K90, half dose and without fertilizers. Methods of tillage included moldboard and subsurface to the depth of 25–27 cm and minimal – disking to the depth of 14–16 cm. It was established that intense irrigation improved pumpkin yield in 2.0-2.2 times comparing with rainfed variant. In water-saving variant there was marked the decreasing of pumpkin yield by 32.2–37.4 % comparing with intense irrigation, while the savings of irrigation water were 1140 m³/ha. The greatest efficiency of fertilizer use was obtained at applying the recommended fertilizer dose which increased the yield by 10.5–20.7 % against the variant without fertilizing. For this case one kilogram of applied fertilizers provided 33.4 kg of additional production. Moldboard tillage facilitated to higher crop productivity which was by 7.4–11.3 % higher than at minimal tillage. The optimal combination of technological elements for pumpkin growing is intense irrigation regime, moldboard tillage and the recommended fertilizer dose.
Keywords: pumpkin, irrigation regime, mineral nutrition levels, methods of tillage, crop yield, irrigation water savings, resource savings.
