The impact of nitrogen and organic matter on winter canola seed yield and yield components.

Abstract

Canola is becoming an important oilseed crop grown in rotation with wheat in Iran. This study was carried out to evaluate the effect of N fertilization and additive materials including wheat residue and compost on growth, yield and yield components of canola. The experiment was conducted at the Experimental Farm of College of Agriculture, Shiraz University, Shiraz, Iran, located at Badjgah in 2006-2007 and 2007-2008 growing seasons. The experimental design was split plot with three replications. Seed yield responded to the application of both compost and wheat straw and the maximum seed yield was recorded at 50 ton ha-1 of compost treatment. Increasing N caused a significant increase in seed yield. Seed yield showed a significant increase by increasing N from 0 to 100 kg ha-1 at 50 ton ha-1 compost treatment; however increasing N beyond 100 kg ha-1 had no significant effect on canola seed yield. Application of 100 kg ha-1 of N fertilizer at 50 ton ha-1 compost was adequate for optimum seed yield. Results of stepwise regression analysis showed that contribution of yield component of canola varies with change in N fertilizer and organic matter application rates. Soil organic carbon was also shown to increase following application of different types of organic matter.