2015,    N 6 (22)    

ECOLOGY

Chernikov V., Vasenev I., Valentini R.

Influence of the humic acids structure on the greenhouse gases potential soil emission in samples from the Dorenko-Pryanishnikov Long-term field experiment in the Russian Timiryazev State Agricultural University

The principal reason of current Global climate change is the characteristic for XXI century accelerated growth in the atmospheric greenhouse gases (GHGs) content, primarily in carbon dioxide (CO2), methane (CH4) and nitrogen oxide (I - N2O). The main part (up to 60-80 %) of the terrestrial ecosystems greenhouse gases fluxes has a soil origin so it is very important to evaluate the GHGs soil emission potential and the impacts of the principal factors that determine it. The main source of the greenhouse gases generation in soil is its organic matter and its relatively stable part, called humus. The functional features of humus and its resistance to external impacts are determined by its structural-functional composition and, in particular, the humic acids structure which is typomorphic for many soils. The humic acids structural-group composition identified by the pyrolysis mass spectrometry method allows to estimate the potential soil greenhouse gases emissions from the investigated soil samples. The conducted analysis of arable horizons in the representative for the Central region of Russia versions of the cultivated sandy-loam sod-pale-podzoluvisols at the Dorenko-Pryanishnikov Long-term (centennial since 2012) field experiment in the Field experimental station of the Russian Timiryazev State Agricultural University allows to evaluate the impact of the different agricultural land-use practices on the humic acids structure of the investigated soils and the potential of their GHGs emissions under different land use. Streak enforcement of the classical procedure of extraction and purification of the analyzed humic acids allows to minimize the noise effects of potential pollutants. The investigated experiments with permanent black fallow, permanent rye without any fertilizing and permanent rye with periodic application of manure and lime give an idea about the influence of extremely contrasting agricultural impacts on the structural-group composition of humic acids of the long-term cultivated sod-pale-podzoluvisols and their potential soil greenhouse gases emission that is very important for estimating the functional-ecological state of zonal for the Russian Non-Chernozemic region sod-podzoluvisols in conditions of the XXI century principal climate and technological challenges. According to the obtained research results the humic acids of arable horizons of the centennial experiment «permanent rye with periodic application of manure and lime» not only contain the greatest content of gases, including the greenhouse ones, but also conserve in soil better. This helps to reduce their emission to the atmosphere and to increase the sustainable biological productivity in such field agroecosystems. The normalization of the air-regulatory environmental function of the investigated sod-podzoluvisols in the Central region of Russia creates favorable conditions for the regional greenhouse gas fluxes stabilization that, in turn, is an important factor for the declared by the Paris Summit prevention of the characteristic for XXI century accelerated global changes in climate and biota.

Keywords: ECOLOGY, AGROECOLOGY, GLOBAL CHANGES, GREENHOUSE GASES, SOD-PODZOLUVISOLS, LONG-TERM EXPERIMENTS, SOIL FLUXES, SOIL ENVIRONMENTAL FUNCTIONS, SOIL FUNCTIONAL-ECOLOGICAL ASSESSMENT, HUMUS, HUMIC ACIDS, HUMUS STRUCTURE