بررسی تأثیر گیاهان پیشکاشت و کود نیتروژنه بر میزان ماده آلی و نیتروژن خاک و عملکرد گندم

In order to study the effects of preceding crops and nitrogen fertilizer rates on soil organic carbon and total nitrogen, grain yield and some qualitative characteristics of wheat (cv. Chamran), a split plot experiment in complete randomized blocks with three replications was conducted at Ramin Agricultural and Natural Resources University during 2008-2010. The experimental factors included different preceding crops (wheat, canola, barley + berseem clover, mung bean, corn, rice and fallow) as main plots and four nitrogen levels as subplot (0, 45, 90 and 135 kgha-1). The results indicated that the highest amount of soil organic carbon (0.68%), grain yield (4833 kg ha-1) and grain protein (14.3%) of wheat was obtained after mungbean and 135 kg N ha-1) while the highest amount of soil total nitrogen (0.065%) was obtained after rice and 135 kg N ha-1. It was concluded that mungbean could be introduced as proper preceding crop for wheat because of lower amount of C/N, increasing the amount of soil organic carbon and total nitrogen and increasing the grain yield of wheat.