The organic matter of the soil and humus are heterogeneous in composition. That is why the nature of soil organic matter has not yet been fully understood and causes many discussions. The purpose of this work is to study the identification features of humus in the process of peat's transformation. The results of a fiveyear experiment studying the processes of organic matter transformation in organic-mineral substrate based on peat growing coniferous seedlings in greenhouses are presented. In the dynamics of the group and fractional composition of humus for several years the biochemical essence of the humification process is revealed. To extract specific humic substances from the organogenic substrate, we used the method of fractioning humus into groups and fractions, which is a stepwise sequential extraction using solutions of sodium hydroxide and sulfuric acid. It was found that the organic matter of the substrate passes through three stages of transformation: hydrolysis of organic products → initial transformation → humification of lignin structures. There is a significant change in the ratio of the three main groups of humus in favor of humic acids at the third stage. In general, the system is tends to its most stable state: aromatic structures are copolymerized, the core of humic substances is densified, and humus gradually "matures".

Under conditions of field production experiments, it was shown that the large-tonnage waste of hydrolysis production is the hydrolysis lignin (HL), which can act not only as a source of organic matter in organic or organic-mineral fertilizers, but also serve as a matrix for microorganisms, contributing to improvement of phytosanitary state of soils. It was shown that HL not only contributes to improvement of physicochemical properties of soils and replenishment of humus reserves, but also increases the resistance of plants to diseases, providing a yield increase by 10-20%. In this regard, the integrated use of HL with microbiological compounds is of particular interest. It was revealed that use of HL in combination with bacterial compound – “Mizorin”, provided a statistically significant yield increase (2 t/ha or 6.6%). At the same time, the plants’ damage by common scab decreased from 0.75 to 0.46 points. The observed effect can be caused by the fact that the beneficial microflora, which is part of the “Mizorin” product, is significantly activated due to the branched matrix of lignin.

No abstract

The work presents the formation of a system for assessing soil fertility and plant development using test monitoring polygons. Monitoring polygons became the basis for the introduction of modern technologies to increase plant productivity and soil fertility. The monitoring sites were located in the main agro-climatic regions of the Leningrad Region on soil types typical for the respective region. Analysis of the dynamics of the main parameters of soil fertility in test plots shows a tendency towards a decrease in the content of mobile forms of potassium and acidification of soils, as well as other signs of degradation. A decrease in soil fertility is associated with a decrease in the proportion of applied fertilizers and a decrease in soil liming. This process develops on all types of soils, with the exception of those areas that are located in suburban farms. The data for the test sites are consistent with the overall results of the agrochemical surveys. For industrial practice, test sites and information collected on them can serve as “information keys” for decoding space and aerial photographs in order to assess the state of agroecosystems, monitor changes in soil fertility and plant development. On the example of the cultivation of spring wheat, the way of precision assessment of the management of the productivity of cultivated crops and the increase of soil fertility is shown. The mechanism for the implementation of the plant productivity management system was carried out with the introduction of elements of precision farming.