EFFICIENCY OF CULTIVATION OF LENTIL VARIETIES "VEKHOVSKAYA" ON DARK CHESTNUT SOILS DEPENDING ON THE BACKGROUND OF MINERAL NUTRITION AND NITROGEN FERTILIZERS

mineral nutrition; lentils; nitrogen fertilizers; productivity; yield increase; nitrate nitrogen; optimal level.

Abstract

The relevance of the work is substantiated the existing need to optimize nitrogen nutrition for the cultivation of lentils on dark chestnut soils in the Akmola region. The experiments were conducted in JSC AF Aktyk in 2018-2020. The purpose of the research was to optimize the nitrogen nutrition and the use of fertilizers to increase 16 the productivity of “Vekhovskaya” lentils. It has been established that the yield of “Vekhovskaya” lentils was significantly affected by the initial content of nutrients in the soil and nitrogen fertilizers. The maximum yield increase was obtained on the P90N60 treatment - 9.2 dc/ha. The use of nitrogen fertilizers leads to a significant increase in protein content. The combined application of nitrogen and phosphorus fertilizers also leads to a significant increase in protein content compared with the introduction of only phosphorus or nitrogen fertilizers. A high correlation has been established between the content of nitrate nitrogen in the soil and yield (R=0.81; 0.96). The highest yield was observed on P90N60 treatment with a nitrogen content of nitrates of 17.3 mg/kg in a layer of 0-40 cm - 29.1 centners/ha in 2020. Efficiency analysis show that the highest payback of lentils was obtained when applying 30 and 60 kg of a.i. nitrogen against the P90 background, which amounts to 3.3 and 6.3 kg/kg a.i., respectively. Thus, it is cost-effective to cultivate lentils of the “Vekhovskaya” variety when soil nitrogen nitrates are in the range of 15-17 mg/kg and in the ratio with phosphorus as 1: 1.5-1,7, this potentially allows to get the max net income (34 thousand tg/ha) and return on the unit of fertilizer cost (5.2 tg).