GREEN-MANURE PRODUCTIVITY OF OILSEED RADISH UNDER LATE-AUTUMN VEGETATION CONDITIONS

Over a three-year cycle of field studies, the green-manure potential of oilseed radish was assessed in terms of the efficiency and practical feasibility of its intermediate cultivation at late-autumn periods of green-manure biomass formation on grey forest soils under unfertilized conditions. The implemented assessment included both general parameters of weight and morphometric characteristics of the plants and their formation dynamics in the interval from 10 days after full emergence to 70 days before their intended green-manure incorporation. The chemical composition of the leaf-stem biomass was examined and detailed according to a set of criteria, particularly from the standpoint of classical zootechnical indicators such as crude protein, fat, fiber, and ash content. The complete mineral composition was also considered, including the contents of phosphorus, potassium, calcium, and sulfur, which made it possible to analyze the potential effects of using this biomass as green manure and its possible positive impact on the soil profile and nutrient availability for subsequent crops under this green-manure option. Additionally, based on the obtained structure of the chemical composition of the plant biomass, the potential dynamics of its decomposition in the soil were analyzed with regard to the rates of mineralization and immobilization of released macro- and microelements. Generalizations were made regarding the role of hydrothermal conditions during the period of green-manure biomass formation on its chemical structure and the accumulation of several elements. The prospects of using this timing of green-manure incorporation within bio-fumigation technologies for soil rehabilitation and restoration of low-productive and agrochemically degraded soils were evaluated. An assessment was conducted of the specific features of oilseed radish plant morphometry, including variations in the development and mass of the taproot system, and the formation of major vegetative organs in relation to the photoperiodic response of plants under gradually decreasing temperatures during the period of biomass accumulation for green-manure use. General conclusions were made regarding the feasibility and potential of late-autumn green-manure agrocenoses of oilseed radish in the study area, and prospects were outlined for further research in the field of accompanying analysis of the green-manure value of the formed root biomass, as well as its possible influence on the soil fertility conditions of grey forest soils.