Wpływ wysokości opadu na wymywanie substancji organicznych i mineralnych z gleb uprawnych

The concentration and the load of organic and mineral matter in water (lowing out from rural areas during a wet and a very dry years has been researched. Some drained and not drained areas were chosen. It was stated that the concentration of the matter in water depends on grain-size distribution (higher values in light soils), dewatering intensity (higher values in drainage water than in ditch water) as well as rainfall quantity (higher values over the dry year). The amount of eluted matter was dependent, first of all, on the grain-size distribution of soil (higher values were observed in light soil) and the water outflow which is highly correlated to rainfall quantity and a kind of drainage system. During the wet year 13 kg C, 245 kg Ca, 27 kg Mg, 25 kg Na, 18 N-NO₃, 13 kg K, 1.1 kg N-NH₄ and 0.4 kg P were eluted from light soil and 3.7 kg C, 82 kg Ca, 12 kg Mg, 9 kg Na, 3 kg K, 3.4 kg N-NO₃, 0.5 kg N-NH₄ and 0.15 kg P were eluted from heavy soil. The elution from light soil during the very dry year was as follows: 4.1 kg C, 68 kg Ca, 7 kg Mg, 11 kg K, 10 kg Na, 7 kg N-NO₃, 0.5 kg N-NH₄ and 0.3 kg P from heavy one: 1.6 kg C, 17 kg Ca, 2 kg Mg, 2 kg Na, 0.7 kg K, 0.4 N-NO₃, 0.07 kg N-NH₄ and 0.03 kg P.