Proceedings Volume 2010 (format .pdf) - SimpBTH

EFFECT OF SOIL PROCESSING AND FERTILIZATION ON THEOCCURRENCE OF WEEDS IN ALFALFA SEEDIVAN DIMITROV, SVILEN RAYKOV 11 Shumen University “Ep.K.Preslavski, e-mail:rajkov_svilen@abv.bgABSTRACTThe success for growing of alfalfa is being set before its sowing. Important are the choice of area,the method of soil treatment and mineral fertilization to ensure creation of durable and high-yieldplanting alfalfa.Major problems in the cultivation of alfalfa are weeds with their high species diversity and highenvironmental and biological plasticity, which facilitates their rapid dissemination and adaptation.Researches were conducted in a field experiment for the period of four years to determine theinfluence of soil processing and fertilization on weeds development in alfalfa crops grown for forage.The survey results show that at least weeds per square meter were found in versions of looseningwithout inverting the layers of 12-15 cm, due to good crop garnish and better physical characteristicsof soil in the arable layer. The highest is the weeds density in variants with a ploughing depth of 12-15 cm - 10.2%, followed by ploughing of 18 -22 cm and 30 to 35 cm, respectively, 9.24 and 9.90percent. Lowest is the stage of weeds in the variant with N 2,3 P 10 K 3,5 , nitrogen½ in I year, ½ year inIII year for the phosphorus and potassium as a stock and non-fertilized control respectively 5.2 and5.9 percent compared to alfalfa yield, followed by the variants with fractional introduction ofphosphorus fertilizer.Key words: alfalfa, weeds, soil processing, fertilizationIn Bulgaria alfalfa is the main grass-fodder crop. It provides the mostprotein per unit area due to the symbiosis with the nitrogen-fixing bacteria, withoutrequiring high doses of nitrogen fertilization.The success for growing of alfalfa is being set before its sowing. Importantare the choice of area, the method of soil treatment, bringing to gardening state, asthe choice of suitable seed to ensure creation of durable and high-yield plantingalfalfa. Not a little is the role of good nourishing regimen maintaining through theuse of mineral fertilizers.The creation of high agro-background for growing alfalfa enhances thecompetition by weeds. Due to their rapid pace of development they grow older andaccumulate big biomass, while culture sprout slowly.Integrated control is best suited to maintaining the purity of crops withalfalfa. Soil processing is the central group in it. The weed vegetation is limitedsignificantly by performing timely processing, at appropriate technologicalconditions and on the required depth. (Dimitrov etc. 2003, T. Tonev 2000, AlbrechtH & Sommer, H., 1998).The chemical method is one of the highly efficient, fast and easily methodsof weed control (Dimitrova, Ts., 2000). The majority of weed species rapidlydevelop resistance to most of the preparations for a long time (Joene, W. at all.192