VARIOUS SOIL QUALITY PARAMETERS AND HUMUS CONTENT EVOLUTION IN CONVENTIONAL AND MINIMUM TILLAGE SYSTEMS.

An experiment was laid out on a Haplic Phaeozem (PH ha) (WRB-SR 2014) characterized by a dark colored mollic A horizon (Am), a cambic B horizon (Bv), and an accumulation calcareous illuviation horizon (Cca) of secondary calcium carbonates which occurs deeper than 125 cm (SRTS, 2012). Clay content in the first 40 cm varies between 39.4 and 42.6%, total nitrogen is 0.186%, available phosphorus soluble in the ammonium acetate lactate solution (PAL) 76 mg/kg, available potassium soluble in the same solution (KAL) 250 mg/kg, and soil reaction (pH) 6.3. The land is slightly uneven, groundwater below 5 m depth. The humus content was average in the beginning of the experimentations after which increases were noticed especially in the upper layer (5-10 cm). Soil humus content evolution following different agricultural technologies use was similar at all three studied depths, with increases in the case of minimum tillage system, but without statistically significant differences as compared to the classic one. Therefore, the various agricultural technological systems must assert the conservation and increase of soil organic matter, respectively, the soil humus supply, through their technological chain links. [ABSTRACT FROM AUTHOR]