The Main Physical and Chemical Characteristics of the Soil, Influenced by Conventional and Conservative Systems in Areas Susceptible to Aridification

In this paper the influence of soil tillage on physical and chemical and characteristics of soil from different pedoclimatic areas from Romania was studied. Two soil tillage systems were experimented in Olt County, mostly in Iminog Plain, part of the Boian Plain: conventional (classical) and conservative (minimum tillage) at: Brebeni, Olt County; Adunații Copăceni, Giurgiu County; Constantin Brâncoveanu, Călărași County; and Roșiori, Brăila County. The identified soil classes in the area are Luvisols and Chernozems, with the types Haplic Luvisol and Haplic Chernozem (WRB-SR 2014). Soil samples were collected by 5-10; 25-30; and 45-50 cm depths and their physical and chemical properties were determined in the laboratory according to standardized methodology. Soil texture varied from coarse (silt loam) to fine (medium clay), no matter the soil tillage system. Other soil physical characteristics, such as resistance to penetration and total porosity showed slightly more favorable values in the conservative system. Soil chemical properties also varied. Soil reaction (pH) ranged from moderately acid to slightly alkaline and proved to be a bit more favorable for plants growth in the conservative system. Organic matter contents were very low - average, slightly better accumulating in the conservative system. Soil supply with nutritional chemical elements (nitrogen, phosphorus, and potassium) was very low - average for nitrogen and very low - high for phosphorus and potassium. Except for the potassium, which had better values in the conservative system, no significant differences were noticed between the two soil tillage systems. Soil cation exchange properties framed the samples in the oligomesobasic - eubasic classes. Samples of the conservative system generally had a better base saturation degree. Although soil physical and chemical characteristic in the investigated plots differ relatively little between the working systems slight improvements are noticed from these points of view when minimum tillage technology is applied. It is to be predicted that constant and consistent application of conservative technologies will bring about better soil fertility properties preservation and even their improvement.