Effects of Wheat Straw and Nitrogen Fertilizer on Yield and Yield Components of Garlic (Allium sativum L.)

Garlic (Allium sativum L.) is a valuable medicinal and industrial plant that its production has long history in Iran. In order to study the impacts of different amounts of wheat straw and nitrogen fertilizer on yield and yield components of garlic، a field experiment was performed as factorial layout based on a randomized complete block design with three replications at the Research Station، College of Africulture، Ferdowsi University of Mashhad، during growing season of 2011-2012. Treatments were four rates of wheat straw (0، 5، 10 and 15 t ha-1) and four nitrogen levels (0، 50، 100 and 150 kg ha-1). Nitrogen was applied as Urea before the planting time. The results indicated that the simple and interaction effects of wheat straw and nitrogen fertilizer were significant on leaf dry weight، yield components، biological yield، economic yield and harvest index of garlic. By increasing wheat straw from zero to 10 t ha-1 growth characteristics، yield components and yield of garlic enhanced، but adding more than this amount declined those traits due to temporary loss of nitrogen under improvement in population and activity of soil microorganisms. The highest and the lowest economic yield were observed in 10 t ha-1 straw wheat with 150 kg N ha-1 (112. 2 g m-2) and 15 t ha-1 straw wheat whithout nitrogen (24. 8 g m-2). Adding nitrogen to the soil improved growth characteristics، yield and yield components of garlic due to simulate in vegetative growth.