Itt - Magyar Talajtani Társaság

Talajtani Vándorgyűlés, Sopron, 2006. augusztus 23-25.SummaryThe Carpathian Plains have relatively favourable agro-ecological conditions forrainfed biomass production. But! These favourable conditions show high spatial andtime variability; often extremes and hardly predictable; and sensitively react to naturalor human-induced stresses.Generally favourable agroecological conditions are limited or threatened by soildegradation processes; extreme moisture events; unfavourable changes in thebiogeochemical cycles of plant nutrients and potentially harmful soil pollutants.The risk, probability, frequency, duration and „seriousness” of extreme moistureevents, as flood–waterlogging–overmoistening (too much water) hazard, or droughtsensitivity(water deficiency) are increasing and they often happen in the same year atthe same place. The reasons of these situations are the high, random (and hardlypredictable) spatial and time variability of atmospheric precipitation; the rain–snowratio and snowmelt intensity; macro-, meso- and micro-relief; soil conditions, especiallythe physical–hydrophysical properties of soils; natural vegetation and land use pattern.Their main consequences are: losses in wate-, soil, organic matter, plant nutrients, biota,plant, yield and energy; and the increasing hazard of undesirable environmental sideeffects.Under such conditions the fact that in Hungary the soils represent the highestpotential natural water storage capacity has special significance. In the pore space of the0–100 cm soil layer 30–35 km³ water can be stored, which is more than half of the 50–55 km³ yearly atmospheric precipitation. The main reason of the increasing hazard ofextreme hydrological events is that this huge potential water storage capacity cannot beefficiently used because of the following reasons:– the pore space is not empty, it was filled up during the previous rainy periods(„filled bottle” effect);– the water infiltration to the soil is limited by a frozen („frozen bottle” effect),or a compact, hardly penetrable („closed bottle” effect) soil surface or near surface soillayer;– the infiltrated water is not stored within the upper soil layers, but percolatesdownward into deeper horizons, or to the groundwater („leaking bottle” effect).It can be concluded from these facts that the main goals of efficient soil moisturecontrol are: to help the infiltration of water into the soil; and to help the useful storageof infiltrated water within the soil profile in plant (biota) available form. These effortswill simultaneously decrease evaporation and filtration losses; improve the moisturesupply of plants; and reduce the risk of unfavourable environmental side-effects.BevezetésAz emberi élet minőségének kritériumait illetően a különböző társadalmaktagjainak véleménye, a természeti és gazdasági viszonyoktól, emberikarakterüktől, szociális körülményeiktől, lehetőségeiktől, történelmihagyományaitól, befolyásoltságuktól, egyéni és csoportérdekeiktől függőennagymértékben különbözik, s időben is jelentősen változik.8