Conditions and factors of humus formation in soils of mountain and foothill

On the basis of information on the climatic factor, the intensity of humus formation in the soil was estimated. It was revealed that as the transition from the plain to the foothills and low mountains due to changes in atmospheric precipitation and hydrothermal regime, the period of biological activity (PBA) of the soil increases from the plain to the mountains. The balance of annual radiation in the foothill plain is 47 kcal/cm2, in the high-mountain belt - 53 kcal/cm2. As the transition from the plain to the mountainous part of the relief, an increase in soil PBA was revealed and, in accordance with this, the content and reserves of humus, as well as labile humic substances in the humus composition, increase. By the type of humus, light gray soils are humate-fulvate and fulvate; typical, dark gray soils and mountain brown soils, fulvate-humate; light brown meadow-steppe soils, and humate. It also provides information on the energy reserves of humus for the considered soils. The correlations between the indicators of PBA and humus for horizon “A” in the studied soils were calculated.

Potato yield on dark gray soils when using microbiological preparation

Increasing the yield and quality of potatoes is one of the most important tasks of potato industry. A promising method of increasing the productivity and quality of potatoes is to use microbiological preparations. Their action is due to the use of the properties of microorganisms that can transform the elements of soil nutrition from forms inaccessible to plants to assimilable ones. Consequently, it can be concluded that the study of potato productivity on the dark gray forest soil using the microbiological preparation Biocomposite-correct is an actual area of research. The results of the conducted research show that the used preparation Biocompositecorrect had a positive effect on the elements of the crop structure and potato yield.The optimal rate of application of the preparation Biocomposite-correct (3.0 l/ha with a working fluid flow rate of 400 l/ha), was determined in the course of the experiment. On average, the maximum increase of the mass of potato tubers from one bush was observed in the variant with the use of Biocomposite-correct in the dose 3.0 l / ha (+ 387.1 grams), which is 92.2% more compared to the control, where the maximum yield was 24.2 tons/ha.

Numerical methods to recognize the soil types in the forest steppe

The authors generalized and summarized original and literature data with the view of studying the gray and dark-gray soils in the Volga-Kama forest steppe. The methods of multidimensional statistics permitted to determine the position of these soils in the available soil classification system. A great number of soils described by different researchers within the framework of Russian soil classification system (1977) were formalized in conformity with that published in 2004. In the latest classification system of soils in Russia the reliable differences in the humus horizon of gray and dark-gray soils are shown in the content of humus, exchangeable bases, clay fraction, acidity and thickness as well as in the thickness of the leached layer (up to the C horizon) and the humus storage within the one meter of soil (t/ha). The methods of numerical classification allowed determining discriminated functions and classify more exactly the studied soils in the Volga-Kama forest steppe. Based upon statistic processing of the obtained data the limits for properties of the humus horizon are suggested to distinguish the gray and dark-gray soils. The visual imagination widely adopted now to recognize the types of gray and dark-gray soils should be added by limits of their varying properties. The obtained results presented in this paper may be useful to improve the idea on properties of gray forest soils. The suggested criteria to recognize the studied soils may be applicable for studying and systematizing these soils as well as for purposes of land use, elaboration of regional database and in projects of ecological territory optimization.

A COMPARISON OF HUMIC FRACTIONS OF CHERNOZEMIC AND LUVISOLIC SOILS BY ELEMENTAL ANALYSES, UV AND ESR SPECTROSCOPY

The Ah horizons of a Brown–Dark Brown–Black–Dark Gray–Gray Luvisolic sequence of Canadian grassland and forest soils were studied. Clay-associated humus was present in greater proportions in the grassland than in forest soils, particularly in the grassland soils of the more arid regions. Amounts of alkali-pyrophosphate-extractable humus increased in the Brown to Gray Luvisolic sequence. Alkali-pyrophosphate-extractable humic acid (HA-A) contents were greatest in the Black and Dark Gray soils. C:H ratios, extinction coefficients at 280 nm (E280), and resistance to acid hydrolysis of the HA-A and clay-associated HA-B increased in the Brown to Gray Luvisolic sequence. Free radical concentrations were least for the Brown and Dark Brown soils, moderate for the Black and greatest for the Gray Luvisolic soils. The data suggest an increase in the proportion of aromatic components in the humic acids in going from the Brown to the Gray Luvisolic soils. An objective, multivariate similarity analysis based on 22 humus characteristics showed a relationship between soil zone or soil environment and the nature of the soil's humus.