Sėjomainų poveikio dirvožemio savybėms vertinimas ekologiniame ūkyje

Abstract

The studies on soil properties were carried out in 2017 in the Southern Lithuania (Lithuanian Research Centre for Agriculture and Forestry, Perloja Experimental Station) in ecological crop growth areas. The ecological farming has been taking place since 2011. The main aim of the study was to evaluate the balance of organic matter and chemical parameters in soil, to identify the features of crop root biomass and to determine the activity of soil microorganisms in crop rhizosphere of different crops in several rotations. The studied soil was characterized by low humus content (up to 1.8 percent) and low nitrogen content (up to 1.1 g kg-1), and differed especially by organic carbon concentrations in the humus horizon (0-20 cm in depth). Concentration of the organic carbon (Corg) varied from 11.7 to 28.2 g kg-1 and depended on the crop rotation plants. The highest Corg was found in the soil with red clover, and the lowest – in the soil with summer or winter cereals. During active vegetation, dehydrogenase activity varied within the range of 12.3 – 19.8 μg g-1. The activity of dehydrogenase enzyme was higher and changed with the trends of Corg change in humus horizon. The highest C/N ratio was found in the clover fields of I and II year of use (approximately 22/1 on average), and the lowest one – in the winter wheat (after white mustard) area (approximately 16/1) and even in peas area (approximately 18/1). It might be assumed that at C/N ratio of 16-22/1 the mineralization rather than humification of the organic matter is still predominant in the mineral soils, thought, the ecological farming was started since 2015.