Hydrolases activity in differently managed agro-ecosystems.

Soil samples were collected from different farming fields of the Training Farm ( Aleksandras Stulginskis University): extensive (abandoned barley Hordeum vulgaris L. field, meadow and fodder galega (Galega orientalis Lam.) stand), conventional, and organic (winter wheat Triticum aestivum L. and and legumes mixtures) rotation crops in the middle of vegetation, June of 2007-2009. The objective of this study was to determine the soil bioactivity responses (saccharase and urease activity) on different land management systems and main recourses of ecological factors such as soil genesis type, content of soil organic carbon (SOC), total nitrogen (N), and C/N ratio. The trial was comprised of eight experimental plots (three land management systems and two crops groups: legumes and gramineous). Hydrolases activity correlated stronger with SOC (r = 0.7) or ratio C/N (r = 0.6) than that with total nitrogen content (r = 0.5-0.6) Significantly higher mean value of saccharase (27.00 and 12.6 mg CG g^-1) and urease (5.78 and 4.16 mg NH4⁺-N g^-1 24 h^-1) were observed in oatvetch-barley of conventional farming and winter wheat-oat-pea-barley rotation fields of Organic Farm respectively. In most of the studies, it was observed that enzymes behave differently with different SOC content. Without mineral fertilizers application resulted in the least activity of urease (1.13 mg NH4⁺-N g^-1) and saccharase (8.40 mg CG g^-1 24 h^-1). A significant increase of hydrolases activity has been observed in conventional (144- 413% of urease and 49-50% of saccharase) and organic (219-269% of urease and 78-221% of saccharase) farming as compared. [ABSTRACT FROM AUTHOR]