Features of immobilization-mobilization of some macroelements of soil on drained floodplain lands under energy crops

Abstract

The article presents features of immobilization-mobilization of the main macroelements of drained alluvial soils within the limits of the Left Bank Forest-Steppe for the cultivation of energy crops. The objects of the study were meadow alluvial clay loam soil and meadow-bog alluvial clay loam soil, within the experimental plot on the territory of the flood plain of the Vilhovatka River, in the Kharkiv region of Ukraine. In the plot in 2016, perennial energy crops were planted - energy willow (Salix spp.) and giant miscanthus (Miscanthus spp.). Research methods: field - monitoring of groundwater level, annual (2017-2019) sampling of soil; laboratory-analytical - determination of the content of basic organic elements in the soil (hydrogen, carbon, nitrogen) and iron; Statistical-mathematical analysis of the reliability of the research results. It has been determined that the background of climate change in the direction of aridization the properties of alluvial drained soils significantly affects the rearrangement of a pool of iron in the soil on which energy crops are grown. It has been established that in the upper layers of the meadow alluvial clay loam soil under the plants of willow energy and giant miscanthus for three years there were positive changes in the aspect of the process of accumulation-dissipation of movable iron, which was reflected in the reduced content of its divalent form, which is toxic to plants. The effect of growing energy crops over three years on the processes of immobilization-mobilization of the main macroelements on the meadow alluvial clay loam soil indicates the predominance of immobilization processes with respect to nitrogen, which is reflected in the enhanced ratios of Corg / Ntot., which in the third year was in layers 0-20 and 20-40 cm, respectively, 16,6 and 16,3 and 17,4 and 16,5 under willow and miscanthus, while in the control version was equal to 15,1 and 15, 9. Similar processes occur in the meadow-bog alluvial soil. The identified positive changes in the composition of the soil under energy crops are a reasonable prospect in terms of widespread involvement of lands unoccupied in agricultural production for the production of energy raw materials and simultaneous soil remediation