Proceedings Volume 2010 (format .pdf) - SimpBTH

formation in the variant fertilized on the common accepted technology with N 6 P 10K 8, followed by the variant fertilized with N 2,3 P 8 K 3,5 , nitrogen before the sowing,phosphorus and potassium on a stock.Smaller weeds amount was observed in variants with fractional introducingof phosphorus manure as this fertilizer stimulates legume crops and suppresseswheat weeds, which are mainly nitrogen preferring.CONCLUSIONSIn variant with loosening without inverting the layers of 12-15 cm atleast weeds per square meter were ascertained due to good crop garnish and betterphysical characteristics of soil in the arable layer.The highest density of weeds formation is in the variant with ploughingdepth of 12-15 cm - 10.2%, followed by plowing of 18 -22 cm and 30 to 35 cm,respectively 9.24 and 9.90 percent.The lowest weeds formation level is in the variant with fertilization N 2,3P 10 K 3,5 , nitrogen ½ in I year, ½ in III year for the phosphorus and potassium in astock and non fertilized control respectively 5.2 and 5.9 % compared to the yield ofalfalfa, followed by options with the introduction of fractional phosphorusfertilizer.REFERENCES1. Dimitrova, Ts.,1998. Influence of some alternative methods of weed control on yield and qualityof alfalfa for fodder., Plant-growing Science № 7, 569-574.2. Dimitrova, Ts., 2000. Study of some herbicides for weed control in alfalfa in the year of crop.Plant-growing Science № 5, 328-331.3. Dimitrov, I., M. Borisova, D. Nikolova, 2003. Amendment of weed associations under theinfluence of some agricultural factors. Symposium of scientific papers international conference "50Years University of Forestry, Sofia, Department of Plant Protection, p 45 to 48.4. Dimitrov, I., M. Borisova, 1996. Environmental, agricultural and technological aspects of thesystem of soil processing. Soil Science, Agrochemistry and Ecology Section 3 p.217-220.5. Pachev I., 2001. Study on optimization of fertilization on alfalfa for fodder. Proceedings of theUnion of Scientists - Rousse, Obraztsov chiflik.6. Tonev T., 2000. Manual for integrated weed control and farming culture. Higher Institute ofAgriculture, Plovdiv, issue 2.7. Albrecht H & Sommer,Н., 1998, development of the arable weed seed bank after the change fromconventional to integrated and organic farming. Aspects of Applied Biology 51. Weed seed banks:determination dinamics and manipulation, 279-288.8. Bond W & Lenardson, MEK,1999, Organic weed control back to the future., Jn: Proseedings1999. Brighton Conference – Weeds, Brighton, UK, 929-938.9. Joene, W., B. Post, H. Haber., 2000. Weed Science Introduction, Wageningen.197