COMPARATIVE RESULTS OF DETERMINATION OF ORGANIC MATTER CONTENTS (TO THE HUMUS) IN SOIL AFTER NORMATIVE DOCUMENTS GOST 26213-91 AND DSTU 4289:2004

The analysis of regulatory documents (GOST 26213-91 Soils. Methods for determination of organic matter and DSTU 4289: 2004 Soil quality. Methods for determination of organic matter) was conducted in the laboratory of soil protection. It was found that the determination of carbon in the soil for the used normative documents have equivalent. These methods allow to determine of the soil carbon content (soil humus) with high accuracy (mean square error of Qualified value 1,758% was 0.019%). Further conversion of soil carbon in organic matter (humus) with a appropriate coefficients substantially changes the value of this important indicator. According to GOST 26213-91 conversion coefficient of soil carbon in organic matter is one for all types of soil (equal 1.724). For these conditions, the content of organic matter in the investigated soil (chernozems) will be 3.03 %. ISO 4289: 2004 provides for the use of coefficients conversion of carbon in organic matter (humus) for the five types of soil: soddy-podzolic soils - 2.09, gray forest soils - 2.05, chernozems - 1.88, kastanozems – 1.97, brown forest soils - 2.07. According to indicated ISO (4289: 2004) content of organic matter in investigated soil type (chernozems) will be already 3.31% (1.76 * 1.88) or more than 9 % compared to the previous result. Recalculation the content of organic matter (humus) for most soils under ISO 4289: 2004 compared with GOST 26213-91 showed that the increase in this index will be about 21% and for kastanozems - 14%. By results of inspection of Ukrainian soils in the ninth round (2006-2010) soil organic matter (humus), determined in accordance with GOST 26213-91, is an average for Ukraine 3.14%. If we calculate of humus content in the relevant coefficients (ISO 4289: 2004) for all soils of the Ukraine it increases and will be average 3.52% (12% more than the previous result in relative values). Consequently the use of conversion factors of carbon in the organic matter of DSTU 4289: 2004 significantly increases the content of organic matter (from 9% to 21% black soils in the sod-podzolic soils).