A systematic analysis of the past 35-year period of development of the country's agro-industrial complex shows that there has been an intensification of the production of grain and other products of the industry. The contribution of various ecological and economic factors to this process is estimated. It is proved that its material and resource basis is the accumulated, and not yet replenished, soil fertility-a stock of organic matter( humus), macro-and microelements of mineral nutrition of plants, a set of modes and parameters that allow for the production process and form the yield of cultivated crops (marketable products). Reproduction of soil fertility can be achieved only through technologies that include the assessment and adjustment of expenditure and input items of the balance of elements of mineral nutrition of plants in agrocenoses. It is shown that if the current approach is maintained, the limits of the growth of the agricultural sector of the economy will be determined by the annually decreasing potential of the fertility of arable soils, the degradation of which increases every year.

This paper identifies and discusses two trends in the digitalization of soil research data: (1) creation and maintenance of databases containing reflectance spectra of the upper soil horizons in the range of 300–2500 nm and information on the main physicochemical properties of these horizons; and (2) accumulation and actualization of already published spectra in the visible range (400–750 nm) and incorporation of the data on all horizons constituting the soil profile into the spectral databases, which makes it possible to identify both individual horizons and entire profiles. The second trend widely uses color parameters of soils; this applies both to international optical systems and to Russian-specific indicatory systems. The algorithms used in such databases can be applied in studies involving open-access global soil libraries.

An effect of the integrated use of chicken compost, a diatomite-based silicon fertilizer, and a microbial Bacillus amyloliquefaciens preparation on tomato, cucumber, and pepper crops is assessed under greenhouse conditions. The new technology makes it possible to gain an additional high-quality yield for all the studied vegetable crops. The studied agricultural chemical properties of the gray forest middle-loamy soil were preserved after harvesting. Unlike experimental variants using traditional mineral fertilizers, the collected products fall under the definition of “organic” products or products with improved quality indices (the so-called green products). Resources of raw materials for creating nature-like innovative technologies of green agricultural chemistry are calculated. A whole beneficial use of organic resources is possible in the system of measures for “revitalizing” rural areas to maintain soil fertility and prevent “decarbonization.” This will reduce the negative impact of the uncontrolled turnover of nitrogen- and carbon-containing products on environmental components.

Soil is the basis of food systems at all levels. Preservation of ecological functions of the soil cover and its status in areas newly developed or excluded from agriculture determines the rate and occurrence time of ecological risks and threats to food security. The global role and cost of soil resources increase. Russia is characterized by the maximal area of soil cover: approximately 14.5 × 106 km2 or one sixth of the soil cover of the Earth. Soils are underestimated as a unique national wealth and strategic resource. The amounts of applied agrochemicals are insufficient for the reproduction of soil fertility. The food security in the country is achieved and food products are exported due to nonreimbursable expenses of reserves of soil fertility. There are no state documents, which clearly and unequivocally determine the amount and location of arable soils and farm lands required for the modern agriculture and for solution of problems of sustainable development.

The effect of amorphous silicon dioxide (SiO 2 ) on cadmium behavior in the soil–plant system was studied in a field experiment on a flooded paddy soil slightly contaminated by cadmium. The application of amorphous SiO 2 results in a 1.3- to 1.8-fold smaller cadmium accumulation in the aboveground organs of rice and a 1.8- to 2.6-fold decrease in the content of its available compounds, which can be explained by metal sorption on the surface of applied silicon dioxide and by the reaction of monosilicic acid, which forms in the SiO 2 solution, with cadmium. The decrease in cadmium availability is most intensive in the first 2 weeks after SiO 2 application. Amorphous silicon causes a 26.6% increase in rice productivity in the first season and 72.9% in the second. The data obtained testify to the fact that the application rates of traditional mineral fertilizers can be decreased without risk to rice productivity if silicon compounds are used. They should become an integral and important part of implementing the 4R-STRATEGY for fertilizer application and plant nutrition optimization.

Soluble forms of silicon affect a number of physical, chemical, and biological soil properties. Optimization of silicon nutrition enhances plant tolerance to biotic and abiotic stresses. Current climate change and anthropogenic impacts can alter the soil silicon state. Model laboratory experiments conducted with upper horizons of sod-podzolic soil, gray forest soil under different plant associations, chernozem, paddy soil, and red subtropical soil showed that insufficient soil moistening led to a reduction in soil monosilicic acid by 15 to 36% and simultaneous increases in polysilicic acid by 9 to 45%. Soil cultivation resulted in a decrease in plant-available soil silicon. An increase in NaCl concentration in the soil caused an increase in both monomers and polymers of silicic acid by 6 to 79%. The mobile equilibrium and lability of the numerical values of the parameters of the silicon state of the soil–plant system are revealed. These factors should be taken into account when implementing the 4R-STRATEGY for optimizing mineral nutrition in agricultural crops.

The total content and content of mobile forms of potential soil pollutants (Cd, Pb, Zn, Cu, Sr, F, S) are determined in the topsoil in the impact zone of a cement plant and phosphorus fertilizer factory. The total concentration of Cd (4.0 mg/kg), Pb (99.4 mg/kg), F (15.2 mg/kg), and S (479.6 mg/kg) is found to exceed the established maximum permissible concentrations (MPC, APC). The local concentration maximum of the major pollutants is observed at a distance of 0.5 and 1.0 km away from a phosphogypsum stack. Comparing sampling plots equidistant from the pollution source reveals that alluvial soils have accumulated 1.5–2 times more total forms of Cd, Pb, Zn, Cu, S than agrosod podzolic soils.

Soluble forms of Si and Si-rich substances may reduce both metal mobility and toxicity. A series of column experiments were performed to investigate the influence of Si-rich materials on the mobility and leaching potential of certain metals. Column experiments were conducted using sandy soil that had been treated with various forms of a Si-rich substance, i.e. diatomaceous earth, zeolite, amorphous silicon dioxide, and concentrated monosilicic acid. The soil was also treated with soluble forms of Cd, Cu, Ni, and Pb to simulate a contaminated mine site. Application of the Si-rich materials resulted in metal immobilization and reduced leaching. It appears that monosilicic acid can cause both physical adsorption and metal precipitation within contaminated soils. Further investigations are recommended to assess the potential use of this approach for remediation of mine tailings and decontamination mine sites.