Influence of long term organic farming on stress changes of soil

Abstract

As means of agro-environmental protection are becoming more frequently used in the world, lands of organic production getting wider, demand for organic production increasing, studies and research in the field of organic production are becoming more important. The rules of organic production forbid usage of synthetic fertilizers and means of plant protection replacing them with natural means and means of biological origin. Organic farming helps to prevent soil contamination with mineral fertilizers, pesticides, heavy metals, however it may cause certain problems and put soil into stressful situations especially during the transitional period of organic farming. Long-term research at the centre of Agro-environmental Science, at Lithuanian University of Agriculture that stressful condition of soil during transitional period-when main indexes characterizing soil fertility keep decreasing-lasts approximately 8 months. Later on increase tendencies of those indexes are observed. This is maintained also by biological characteristics of soil. Activity of a hydrolysic ferment saccharase and urease in organic farming shows increase in speed of decomposition of hydrolysic carbohydrates and process of mineralization of organic matters intensifying in soil.