Evaluation of Radiation Absorption and Use Efficiency in Row Intercropping of Wheat (Triticum aestivum L.) and Canola (Brassica napus L.)

In order to evaluate radiation absorption and use efficiency in row intercropping for wheat and canola, a field experiment was conducted based on a randomized block design with three replications at Agricultural Research Station of Ferdowsi University of Mashhad during two growing seasons of 2008-2009 and 2009-2010. Treatments included four combinations of row intercropping of wheat and canola (one row of wheat + one row of canola (1:1), two rows of wheat + two rows of canola (2:2), three rows of wheat + three rows of canola (3:3) and four rows of wheat + four rows of canola (4:4)) and their monoculture. Results indicated that the effect of row intercropping was significant on radiation use efficiency of wheat and canola. The highest radiation use efficiency based on biological yield of wheat and canola were observed in monoculture (with 1.6 and 1.04 g.MJ-1) and three rows wheat+ three rows canola (with 1.4 and 0.57 g.MJ-1), respectively. The maximum radiation use efficiency based on economical yield of wheat and canola were obtained in monoculture (with 0.52 and 0.3 g.MJ-1) and three rows wheat+ three rows canola (0.49 and 0.23 g.MJ-1), respectively. The range of land equivalent ratio for radiation absorption efficiency in different row intercroppings of wheat and canola was 1.31-1.61. In general, row intercropping of wheat with canola increased radiation use efficiency and combination of three rows of wheat + three rows of canola was the most promising one.