Effects of weed control methods on soil productivity of beech (Fagus orientalis Lipsky) ecosystems in Western Black Sea region of Turkey

This study was conducted to investigate the effects of weed control methodsduring regeneration practices on soil productivity of eastern beech forest in BlackSea Region of Turkey. The experiment used a randomized block design with threeblocks. The manual treatments were grubbing. Mechanical treatment wasscarification of soil surface and topsoil with bulldozer.One year after treatments, amount of organic matter on mechanical treatedsite was only 1/5 of the grubbing sites. And mechanically treated sites had only 1/7nitrogen (N), 1/3 phosphorus (P), 1/11 calcium (Ca), 1/4 potassium (K) and 1/5sulfur and magnesium of that the grubbing sites.Soil pH on grubbing sites was 0.5 degree higher than that of other sites. Soilcation exchange capacity (CEC) on mechanical treatment sites was only half of thethat of grubbing sites. Analysis of data between 0-20 cm soil depth revealed that soilIVC pool on grubbing plots was 32 % and Mg pool 88 % more than that of mechanicaltreatment sites.One year after treatments, on mechanical treated sites 2.5 times more beechseedling was count than grubbing sites. However, seedling N, P, Ca, K, Mgconcentrations were significantly lower on mechanical treated sites than those ofgrubbing sites.Comparing to grubbing sites about 49, 14, 219, 22, 20 and 31 times more N,P, Ca, K, S and Mg were removed from the mechanical treatment sites respectively.Thus removing top soil and the organic matter with machine during regenerationpractices may lower the sites productivity and effect seedling growth on thisecosystems.Keywords: Soil, productivity, organic matter, weed control, nutrients.