Effect of Tillage System and Rice Residue Management on Grain Yield and Its Components of Rapeseed (Brassica napus L.) as Second Crop in Paddy Fields

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Abstract

To evaluate the effects of tillage systems and rice residue management on yield components, grain and oil yields of rapeseed (Brassica napus L.) as second crop in paddy fields, a factorial experiment was conducted using randomized complete block design with three replications at Rice Research Institute of Iran (RRII), in 2003-2004 and 2004-2005 cropping seasons. The experimental factors were tillage systems at three levels no tillage, minimum tillage (one pass rotivator in depth of 10-15 cm) and conventional or complete tillage (moldboard plow in depth of 30 cm and rotivator) and rice residue management at two levels (R0: without residue and R1: with residue). Plant density, silique number per plant, grain number per silique, 1000-grain weight, biological yield, harvest index, oil percent, grain and oil yields and C:N ratio were measured. Results showed that there was a significant difference between tillage systems for grain and oil yields, biological yield, harvest index, plant density and silique number per plant. In addition, the effect of rice residue management and interaction of tillage system × residue management was not significant on any of the characteristics, except plant density. No tillage system with residue had the lowest grain and oil yields. Minimum tillage system (2033 kg/ha) and conventional tillage (2255 kg/ha) showed no significant difference for grain yield, however, they were significantly different from no tillage system (1455kg/ha). Results also showed that despite the higher grain yield in conventional tillage system, minimum tillage system with and without residue had relative advantages due to reducing the costs of tillage operations.

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