Diagnosis of the functional state of transformed acid soils agroecosystems depending on long-term anthropogenic loads

Y. Olifir*, A. Нabryel, T. Partyka, O. Havryshko and H. Konyk

Institute of Agriculture of Carpathian region NAAS, 5, Hrushevskoho Str., UA81115 Obroshyne, Pustomyty district, Lviv region, Ukraine

Abstract:

The main priority of agro industrial production has always been and remains to provide
the global population and its yearly increments with food food. The issue of soil fertility improvement is still the most important task of agricultural science. The assessment of the agroecological condition of Albic Stagnic Luvisol using carbon dioxide emission, redox potential, and biotic activity was carried out, based on modern methodological approaches, such as soil quality evaluation via ecologically-related biological parameters. Carbone dioxide emission, redox, and biological processes in long-term stationary experiment depend on the degree of soil acidity reduction. Soil acidification can be minimized through chemical melioration with the combined application of different doses of mineral fertilizers and manure. It was found that carbon dioxide emission is optimal in an organo-mineral fertilizing system with application of 10 t of manure per 1 ha and N₆₅Р₆₈K₆₈ with lime dose (2.5 t ha^-1) calculated according to pH buffering capacity. It is due to oxidative and moderately oxidative conditions created. This organo-mineral fertilizing system also increases the number of aerobic bacteria and overall biological activity. The mineral fertilization and the use of Albic Stagnic Luvisol without fertilizers are accompanied by increased mineralization, growth of reductive processes, and the number of moulds. Studies have shown that it is advisable to include CO₂ emission, redox potential and biological activity along with physicochemical and agrochemical soil properties to assess the influence of different anthropogenic loads on soil formation.

Key words:

acidity, Albic Stagnic Luvisol, CO2 emission, fertilizers, liming, microbiological activity, redox potential

Relieving the calcium deficiency of field soils by means of liming

V. Loide

Estonian Research Institute of Agriculture, Teaduse 11, Saku 75501, Estonia;e-mail: valli.loide@mail.ee

Abstract:

Over 22% of Estonian field soils are calcium-deficient and acidificated, and are also among the poorest soils in Estonia in terms of humus; their average humus content remains below 2%. Low humus content in calcium-deficient soils results from either, a lesser generation of organic matter on acid soil, or its decomposition speed as affected by the micro fungi, which are dominant in calcium-deficient (Haplic Podzoluvisols) soils. The dissolved organic matter succumbs easily to leaching and transport caused by wind and water (erosion), whereby the fertility of the soil will decline. Thus, calcium plays an important role in ensuring the fertility and sustainability of soil; liming is used to relieve its deficiency. To eliminate calcium-deficiency in field soils, the quick-acting fine dusty limes with 5-year interval 5 t ha-1 are mainly used in Estonia. Paying attention to the dynamics of available calcium content in the soil limed with fine dusty lime fertilisers, it appeared that the calcium content remained at the optimum level in the ploughed layer for only 2–3 years, a considerably shorter period of time than expected. Since the level of fineness determines its ability to dissolve and the effect of lime on the available calcium content in soil, then to improve the effectiveness of liming and, from the aspect of an economical use of resources, it is advisable to use dusty limes with a shorter than 5-year interval and, respectively, in smaller quantities, which would guarantee a more stable calcium content in the soil with a better use of resources. For longer effect, limestone should sufficiently contain a coarser fraction, dissolving only in the 3rd–4th year.

Key words: