اثر روش‌های مختلف حاصلخیزی خاک (شیمیایی، آلی و تلفیقی) بر عملکرد و اجزاء عملکرد شلغم علوفه‏ای (Brassica rapa)

To evaluate the effects of organic, chemical and integrated fertilizers on yield and yield components of turnip (Brassica rapa) an experiment was conducted in research farm of college of agriculture, University of Tehran, Iran, during 2009 - 2010 growing season. The treatments were arranged as randomized complete blocks design with three replications and fifteen different fertilization systems. The results showed that the highest root (tuber) dry matter production (836.2 kg.ha^-1) was achieved by application of Zeoponix+Vermicompost+25% chemical fertilizer while the highest shoot dry matter was produced by Zeoponix + 50% chemical fertilizer and Vermicompost+biological fertilizer+ 25% chemical fertilizer treatments. The highest total forage production (shoot+ tuber) was observed in both Zeoponix+ 50% chemical fertilizer (17613.3 kg.ha^-1) and Vermicompost + biological fertilizer + 25% chemical fertilizer treatments (16000 kg.ha^-1) which out produced the control treatments by 106 and 87%, respectively. Integrated application of organic and chemical fertilizers had a synergetic effect on turnip forage production. Application of integrated fertiliztion system had more positive effect on forage yield compared to individual application of different fertilizers. The results of this experiment also revealed that organic fertilizers were more effective on yield increment of forage turnip than chemical fertilizers.