Hydrotechnical arragement for rice cropping from Banloc – Topolea (Timis) worked since 1786 year. In this paper we present the environmental conditions (climate, geological, geomorphological, and hydrological and vegetation), hydro technical scheme, irrigation regime, the design of field irrigation systems and soil cover. In the irrigated plots for 120 years and 25 years and also in the field limitrophe to the rice cropping it was effectuated physical, chemical, hydrological and morphological determinations (particle –size distribution, air porosity, hydraulic conductivity, pH, CaCO3, soluble salts, humus, macro and microelements content, redoxpotential). The findings and results from the soil and water analysis allow us to have some relevant information about profound impact of the long time irrigation upon soil profile and on the other environmental conditions. The alterations yielded in the internal arrangement and also in the limitrophe zone. The most evidently alterations are observed in the soil profile irrigated for 120 years while in the soil profile irrigated for 25 years the changes are difficult to be recorded. For instance, in the plot with 120 years irrigated a lot of properties are modified: the texture species became clayey, the bulk density are great even in the topsoil (1.33/1.68 g.cm-3), infiltration velocity is diminished from 38 mm.h-1 to 5 mm.h-1 at 50 cm depth, the level of carbonates lowers from 40 cm to 150 cm depth. There are proposed some measures to control land degradation and to increase the economic efficiency of the rice cropping.

irrigation, rice, alteration, bulk density, infiltration

sciences soil

Presentation: poster