Field experiments were conducted in three successive seasons (2019-2021) to evaluate the effects of four commercial organo-mineral fertilizers with biostimulating action (Hendophyt (R), Ergostim (R), and Radicon (R)) on the vegetative and productive performance of young almond trees (Prunus dulcis, cv. Tuono) grown in a semiarid climate in Southern Italy. Foliar treatments were applied three times during each season (at the swollen bud, beginning of flowering, and fruit set-beginning of fruit growth stages). Both 2020 and 2021 were adversely affected by late frosts, resulting in damage to the flowers and small fruits without any positive effect of the biostimulant applications. In contrast, the results obtained during the normal climate year (2019) indicated that the growth of trunk diameter and shoot length of trees tended to increase in biostimulant treatments compared to those of the control. The number of buds and flowers per unit length of the branch revealed no significant differences among years and all compared treatments. However, in 2019, the fruit set percentage, number, and weight of kernels per tree were significantly higher in the biostimulant treatments compared to those of the control. To this regard, the use of biofertilizers is suitable for maintaining soil fertility and improving crop productivity This information holds significance for almond tree growers.

The molecular structure of humus substances from permafrost-affected peat mounds of the East European forest-tundra has been studied with the use of up to date physicochemical methods (C-13 NMR, EPR spectroscopy). The structural-functional parameters of humus substances from these soils are specified by the integral action of cryogenic processes in the active layer, natural selection of aromatic structures in the course of humification, and by the species composition and degree of peat decomposition; they reflect the climatic conditions of peat formation in the Holocene. Humic acids of peat bogs are represented by low-condensed molecular structures with the low portion of carbon atoms of aromatic components, which increases down the soil profile, and by with the high content of non-oxidized aliphatic fragments. Active changes in the portions of aromatic and non-oxidized aliphatic fragments take place at the lower boundary of the active layer in the soils of bare peat spots. Such changes may serve as the basis for further search of the bioindicators of recent climate changes.

Humification plays an important role in stabilization of organic matter in soils of the cryolithic zone. In this context, the degree of organic matter stabilization has been assessed, using instrumental methods, for permafrost peat soils of the eastern European Arctic, based on selected plots from within the Komi Republic (Russian Federation). Humic substances (HSs) isolated from the mire permafrost peats of the forest-tundra sub-zone of the European Arctic have been characterized in terms of molecular composition. This was accomplished using elemental and amino acid fragments (AAFs) composition. Solid-state C-13 nuclear magnetic resonance (C-13 NMR) spectroscopy was utilized to identify the structure of HSs. Changes in the molar x(H) : x(C) ratio, ratio of aromatic to paraffin fragments and ratio of hydroxy AAFs to heterocyclic AAFs along the peat profiles have been revealed. They are due to the activation of cryogenic processes in the upper part of the seasonally thawing layer, the natural selection of condensed humic molecules, the botanical composition and degree of degradation of peat, which reflect the climatic features of the area in the Holocene. Humic acids and fulvic acids of the peat soils showed the prevalence of compounds with a low degree of condensation and a low portion of aromatic fragments. The aromaticity degree showed the trend to increase within the depth. Changes of quantitative and qualitative parameters of specific organic compounds occur at the permafrost boundary of peatlands, which can serve as an indicator of recent climate changes in environments from the high latitudes. The presented data can be useful in the evaluation of soil organic matter stabilization degree in the active layer and below the permafrost table.