The influence of watering conditions and fertilization on crop capacity of bulb onions and processes of water supply on different plant status in the conditions of Northern Step of Ukraine

Abstract

Relevance. Bulb onions are one of the most common and popular vegetable crops in Ukraine, which can be consumed in fresh form throughout the year. In Ukraine, more and more areas under vegetables are irrigated by drip irrigation. However, the average yield of vegetables, and in particular onions, remains at a low level due to the discrepancy of the technology elements that were mainly developed for irrigation by spraying, drip irrigation systems. This determines the relevance of research on the main elements of the technology of plant cultivation: regimes of humidification, fertilization, plant density. Purpose. Determination of the influence of methods and regimes of irrigation, fertilization and plant density on the commercial yield of onions and processes of water consumption in the conditions of the northern steppe of Ukraine. Methods. The research was conducted on the fields of Dnipropetrovsk Experimental Station of the Institute of Vegetable and Melons NAAS during the period of 2011–2014. In the experiment, an acute variety of onions of Batir. The soil of the experimental part is the normal chernozem, low-humus, extracted, mediumgrained. Experiments were conducted in accordance with the "Methodology of Experimental Case in Vegetable and Melons" (2001). The following factors were included in the experimental scheme: the method of watering (A) – without irrigation (control), irrigation with sprinkling (75–80% NH) (standard), drip irrigation (75–80% NH), drip irrigation with differentiated regime (75–80% NH to the formation of the
bulb, 70–65% NH to the penetration of the pen); fertilizer (B) – without fertilizers (control), N90P135K90 scatter (standard), P45K30 locally + 2 feed N15 (fertigation) + 2 foliar fertilizers Reakom 3l / hectar; density (B) – 600 thousand pieces / hectar (standard), 800 thousand pieces / hectar, 1000 thousand pieces / hectar. The determination of the coefficient of irrigation efficiency and the water intake ratio of onion plants was carried out according to the methods given in the book "Irrigated agriculture" (1995). Statistical data processing was performed according to B. O. Dospekhov (1985) Results. Among the studied elements of cultivation technology,the most impact on commodity productivity had the methods and regimes of irrigation, which can be explained by the features of the growing zone, which belongs to the zone of unstable moisture. The most effective method of irrigation (factor A) was a differentiated drop (80–75% of NH to the formation of bulbs, 70–65% of NH to penetration), which increased the yield almost twice. Among the investigated fertilizer variants (factor B), the P45K30 is most efficiently to apply locally, and during vegetation 2 nutrients to carry out with nitrogen N15 and 2 feedings with Reakom of 3 liters per hectare, which ensures increase in commodity yields with respect to control of 8.5 t / hectar, the standard 2,4 t / hectar up to 41.9 t / hectar. The increase in yield is observed at the thickening of crops by 14.5 – 31.8%, with the density of 800 and 1000 thousand pieces / ha. Analysis of yields values found that the most effective combination of technology elements was the use of differentiated drop irrigation (80–75% NH to the formation of the bulb, 70-65% NH to penetration) on the background of fertilizer P45K30 locally + 2 fermentation N15 + 2 recharge Reakom 3 l / hectar and plant density of 1000 thousand pounds / hectar – 55.4 t / hectar. The conducted analysis of water usage by plants of onion bulbs found that irrigation increased the rate of total water consumption by 48.6–69.9%. A significant variation of the irrigation efficiency coefficient is established. The highest water consumption per unit of crop was observed on fillets without irrigation – 119.2 m3 / t. With the use of drip irrigation, the water consumption ratio decreases with respect to control by 16.1 – 18.7%, and with respect to the standard (spillage) by 15.2 – 16.9%.
he application of fertilizers reduced the coefficient of water consumption by 16.1 – 22.4%.The lowest water consumption for forming the unit of yield is noted on the variant P45K30 + 2 feed N15 and Reakom 3l / hectar – 96.6 m3/t. The introduced fertilizers improved the development of plants, as a result – more moisture was spent on the formation of the crop, while the proportion of unproductive losses decreases. A similar effect is also observed in the thickening of crops. Analysis of the values found that the lowest water usage coefficient was observed for differentiated drip irrigation (up to 80-75% NH bulbs and 70-65% NH to pen penetration), P45K30 + 2 feeding N15 and Reakom 3l / hectar and density plants 1000 thousand plants / hectar – 74,9 m3/t. According to the results of statistical analysis of data between the commercial productivity of bulbs of the Batir variety and the water consumption coefficient, a close inverse correlation relationship was established at r = – 0.74. The calculation of the efficiency of irrigation has found that on average, the use of sprinkling on 1 ton of increment of yield consumes 200 m3 of water. The cost of drip irrigation is reduced by almost a third – up to 77.8 – 75.1 m3/t. Water is most efficiently used for differentiated drop irrigation in the background of the introduction of P45K30 + 2 feed N15 and Reakom 3l / hectar and plant density of 1000 thousand plants / hectar – the irrigation efficiency is 42.8 m3 / ton. Conclusions and perspectives. The use of drip irrigation against the background of the introduction of P45K30 + 2 feed N15 and Reakom 3l / hectar and thickening of crops to 1000 thousand ps / hectar provides the highest level of commodity yield – 55.4 t/hectar. Increasing the effectiveness of moisture is facilitated by the introduction of fertilizers and increasing plant density, the water consumption ratio decreases by 16.1 – 22.4% with the fertilizer, and with density increase from 600 to 1000 thousand tons / hectar by 20.9% and amounted to 96.8 m3/t. The best coefficient of irrigation efficiency is marked by the drop method – 77.8–75.1 m3. Between the coefficient of water consumption and the yield of onions of the Batyr variety, an inverse close correlation relationship is established at the level r = – 0.74.