DYNAMICS OF NITROGEN ACCUMULATION IN THE VEGETATIVE PART OF SHOOTS OF THE NON-TRADITIONAL FOR RUSSIA LEGUMINOUS CROP CROTALARIA JUNCEA (SUNN HEMP) NATIVE TO TROPICAL COUNTRIES

Crotalaria juncea is an annual shrub from the legume family, native to India and Africa and commonly used here as a green manure crop, mainly because it enriches the soil with large amounts of nitrogen through biological fixation from the atmosphere. In the natural population, their seedlings are quite rare and farmers around the world are still poorly aware of the beneficial properties of these plants. The crop is also rare for Russia, due to the limited area of its possible cultivation and the poor development of the breeding base. The southern regions of the country with a warm temperate climate, in particular the Krasnodar Territory, the republic of Adygea or Crimea, can serve as a place for the possible cultivation of crotalaria in the Russian Federation. The crop can also be actively grown in closed ground conditions. This work is devoted to assessing the growth and development of plants in protected soil conditions with full light culture for 140 days, before the active flowering phase, when all biochemical indicators in morphogenesis are maximum, including the concentration of nitrogen accumulation. The substrate was a soil mixture consisting of typical chernozem obtained from the Kamennaya Steppe nature reserve in the Voronezh region, and 20% additive in the form of volcanic zeolite. The experiment included a block of 50 plants with a germination rate of 66%. Throughout the entire growing season, a systematic account was taken of the dynamics of changes in the morphometric indicators of crop growth (height and dry biomass), as well as the accumulation of mineral nitrogen in it. Based on the results of the research, it was established that these indicators can be described by the following quadratic equations: accumulation of dry biomass - y=0,3325x4 - 3,7533x3 + 14,428x2 - 19,197x + 9,91 (R2=0.99); shoot growth dynamics - y=0,4208x4 - 3,0417x3 + 6,3292x2 + 13,792x + 18,5 (R2=0.99); nitrogen accumulation - y= -0,7075x4 + 8,7117x3 - 38,588x2 + 75,393x - 31,7 (R2=0.99).