Assessment of soil quality in conservative agriculture systems versus conventional agriculture

Abstract

The paper presents the results of the researches carried out in the SCDA Drăgănești Vlașca experimental field, in two agriculture systems, conservative and conventional. Soil samples, taken in two phases, were analyzed in the laboratory to determine physical and chemical parameters: organic matter content, soil structure, bulk density, soil reaction, nutrients (N, P, K, and S) contents, total porosity, and resistance to penetration. Micro biological analyses were also performed: total number of bacteria (TNB106 /g dry soil), total number of micro fungi (TNF103 /g soil), and soil respiration (mg CO2/100 g sol). Soil arrangement state assessed through BD, TP, and RP is more favorable in the case of the conservative system as compared to the conventional one. The analyzed indicators highlight a soil looser arrangement in the conservative system and a certain improvement of the air condition. The slightly positive effects determined by the conservative system application reflect upon the soil hydric and physical state, and a little better conditions are present for water accumulation in soil. Diminished surface traffic permitted the so-called `soil rest` resulting in a natural soil aggregates re-arrangement and a slight improvement of the air-water system. From the chemical point of view, the soil in both agriculture systems presented characteristics relatively favorable for growth and evolution of cultivated plants. From the micro biological point of view an increase of the TNF values was noticed at the spring harvest 2017 in two of the three probes made in the soil worked in conservative system as compared both to the autumn harvest and the conventional system, due to the nutrients abundance proceeded from the vegetal biomass left at the soil surface after harvest. Soil respiration as a soil biologic activity indicator closely modelled the TNB and TNF values obtained in both agriculture systems and in both harvest periods, proving that the soil microorganisms’ populations are really active and develop their metabolic and ecologic functions in the soil.