The influence of long–term organic farming on segetic flora composition in the eastern galega (Galega orientalis Lam.) crop

Abstract

Investigations of long-term organic farming effect on the eastern galega (Galega orientalis Lam.) segetic flora species composition were carried out at Experimental Station of Aleksandras Stulginskis University in 2007-2011. The galega field was dominated by loam Calc(ar)i- Epihypogleyic Luvisol - LVg-pw-cc soil, which has been r alkaline (pH 7.4-7.6), having medium humus content (2.00 - 2.88%), phosphorus (P2O5 165-200 mg kg-1) and small and medium amount of potassium (K2O 90-142 mg kg-1). There in galega field after spring barley cover crop cutting were found 51 segetic flora plant species. Crop was dominated by short - lived spring and short-lived overwintering weed species. Number of segetic flora species decreased to 32 units or 19 species during the first year of galega use. Segetic flora species composition varied little from the second year of use and there found 17-20 species of which 11-14 were perennial. Perennial weeds, spreading seeds as well as reproducing by seeds and vegetative began to dominate. Crop was dominated by small, medium, and weak alkaline, moderately rich, rich and the very rich with nitrogen, moderately moist and humid and moderately warm and warm soils and indifferent plants. The highest number of weeds in galega was found after cutting of spring barley cover crop, in the first year of using the number of weeds decreased significantly, and the weed mass decreased only slightly. In the second year of galega cultivation weeds, compared to the first year of cultivation decreased significantly. Comparing the third and fourth years of use galega crop, no significant differences of weeds number and weight were found.