The interdependence between the leaf area index value and soil-protecting effectiveness of selected plants

The study presents results of the one-factor field experiment carried out in years 2005-2011 located on a slope with an inclination of 9%, in the mountain region (southern Poland, 545 m a.s.l.). Soil-protection effectiveness of potato, spring barley and meadow was studied on the basis of vegetation cover forming during whole plant vegetation period, expressed as LAI (leaf area index). The mass of surface runoff from the plots was measured after precipitation and snowmelts causing surface wash-out. The plots were arranged in a randomized block design, in four repetitions. Surface wash-outs were caught in the Slupik's catchers. The soil-protection effectiveness of potato starts when plants cover 80% of the soil surface, in spring barley it was 60%, and for meadow 10%. Reduction of the intensity of surface wash as a result of an increase in the surface of the plants aerial-parts is described in the following simple regression equations: y = -1480.7x + 4094.2 (r = 0.63, n = 216) for potato; y = -59.2x + 157.4 (r = 0.69, n = 200) for spring barley, and y = -1.5097x + 11.6 (r = 0.37, n = 236) for meadow. Meadow protects soil against water erosion 6.8-times more effectively than spring barley and 324-times better than potato. The results enabled verification of the nomograms determining the carbon indicator value in the USLE equation for tested plants under similar conditions.