Physico-chemical and agrochemical indicators of typical chernozem and isohumisol under various tillage and fertiliser systems

The relevance of examining the physico-chemical and agrochemical indicators of soils lies in the fact that these properties determine the level and quality of agricultural crops, thus affecting the food security of the country as a whole. In this regard, the purpose of the study is to establish the longterm impact of different soil tillage and fertilisation technologies on the profile distribution of physicochemical and agrochemical indicators of typical chernozem and isohumisol soils. Under conventional tillage (CTu), plant nutrients were evenly distributed within the upper layer of typical chernozem, with the highest values observed in the 10-40 cm depth range. Under soil conservation tillage, with the addition of straw at a rate of 1.2 t/ha+N12+N78P68K68, the content of available hydrolyzable nitrogen, mobile phosphorus, and exchangeable potassium in the typical chernozem soil was highest in the 0-20 cm layer: 192.30±22.44 and 192.51±22 mg/kg; 63.57±5.762 and 62.07±0.312 mg/kg; 527.14±36.204 and 465.27±5.844 mg/kg for shallow (RTu) and deep (DRTu) soil conservation tillage, respectively. In total at 0-100 cm layer of typical chernozem, the highest content of plant nutrients was observed under DRTu followed by CTu. In Chinese isohumisol, a higher accumulation of NH4 + -N and NO3 -N was observed in the 0-10 cm depth range under no-till soil management, while in the 20-40 cm depth range, plowing resulted in greater accumulation of these nutrients. The total phosphorus content did not notably change with depth. Under the application of fertilisers, the content of nutrients and the reaction value of the medium increased for all tillage treatments of typical chernozem. The content of exchangeable calcium and magnesium did not change considerably on the fertilised inputs. The findings of this study indicate the feasibility of using crop residues with nitrogen compensation and cover crops, in conjunction with mineral fertilizers, to maintain the fertility level of chernozem soils under conditions of limited manure utilisation