The effectiveness of cultivating soybean varieties of different maturity groups in the conditions of the central Ciscaucasia

The studies were conducted in 2017-2019 at the experimental station of the Stavropol State Agrarian University in conditions without irrigation and on the basis of the experimental plots of Agrosakhar LLC with the use of irrigation. The territories of the research sites belong to the zone of unstable humidification, characterized by unstable and uneven precipitation during the growing season of soybeans, elevated air temperatures in summer, when soybean plants enter the phases of flowering and grain filling. At the experimental plots of the SSAU experimental station, the soil is represented by leached chernozem, at the experimental sites of Agrosahar LLC by ordinary chernozem. The purpose of the research is to determine the biological characteristics and efficiency of growing new, promising soybean varieties of the southern ecotype. It was found that the most quickly-ripening variety with a growing season of 96 days is the Bara variety, the longest growing season was noted in the mid-ripening Vilana variety – 129 days. The maximum photosynthetic potential of soybean crops was formed under irrigation conditions: quickly-ripening Selecta 101 variety – 1376, early-ripening Duar variety – 1678 and mid-ripening Zara variety – 2167 thous. m2.day/ha. In terms of yield, when growing soybeans without irrigation in the quickly-ripening group, the Lira variety stood out – 1.59 t/ha, in the early-ripening Selecta 201 variety – 1.75 t/ha and the midripening Zara variety – 1.94 t/ha, when irrigation was used in the quickly-ripening group, the Selecta 101 variety stood out – 2.34 t/ha, in the early-ripening Duar variety – 2.89 t/ha and the mid-ripening Zara variety – 3.14 t/ha. In the conditions of the SSAU experimental station without irrigation and in Agrosakhar LLC the largest profit in the amount of 16028 to 40912 rub./ha was obtained by cultivating the mid-ripening Zara variety with a yield of 1.94 - 3.14 t/ha, and the level of profitability ranged from 49.4 to 108.8%

Soybean Cultivation Cost-effectiveness Depending on Bacterial Preparations and Growth Stimulants Use

Researches and analysis of the data obtained on the basis of the Armavir Experimental Station of the All-Russian Scientific Research Institute of Oilseeds establish the most effective bacterial preparations, growth stimulants and their combination for soybean cultivation under conditions of unstable moisture on ordinary chernozem. The soybeans yield during the seed treatment with the rhizobial preparation Nitrofix P (2 kg/t) in combination with the film former was the highest and amounted to 1.83 t/ha, which is 0.23 t/ha higher than in the control. It also obtained the maximum collection of plant protein – 0,69 t/ha. The highest yields (1.72–1.83 t/ha) and relatively low production costs allow getting quite high profits (19,472–22,191 rub/ha) with complex soybeans seed treatment with rusobial preparations containing a film former. The maximum profitability in the study of seed treatment with rhizobial preparations was obtained in the variants with the use of the preparations Nitrofiks P and Nitrofiks Zh in combination with the film-forming agent – 95–107 %, which is higher in comparison with the use of bacterial preparations by 2–15 %, and with the control by 12–24 %. The most cost-effective (107 %) was the use of rhizobial Nitrofix preparation in its powder form (2 kg/t) combining with a film former. The obtaining soybeans yield – 1.73 t/ha in the treatment of seeds combining with a rhizobial preparation in combination with a growth stimulator Nagro bioenergetic made it possible to get the highest profit – 19 668 rubles/ha. Given the cost of production and profit per hectare rate, the highest level of profitability was obtained when applying seed treatment with the rhizobial preparation Nitrofiks Zh in combination with Albit and Nagro bioenergetic growth stimulants: 91–94 %. Hence it has been established that the bacterial preparations for treating seeds in combination with a film former and growth stimulant use provides high profits and increases the soybean cultivation profitability level