Changes of some agro-chemical parameters of Pellic Vertisol (FAO) soil type in growing cereal crops under organic system of agriculture

V. Koteva
Abstract. The investigation was carried out in a field certified for organic agriculture, on soil type Pellic vertisol (FAO) during 2004 – 2012. The changes in soil acidity, total humus content and reserves of mineral nitrogen, mobile phosphorus and available potassium in soil after growing of cereals without soil organic fertilization were followed. The obtained results were compared to the values of these indices from the same soil type subjected to intensive cultivation (conventional system of agriculture) and the amounts obtained from soil covered with perennial grasses (virgin soil). The realization of the production potential of common wheat and winter barley grown on Pellic Vertisol without soil organic fertilization is pointed out.