Evaluation of yield and radiation use efficiency in intercropping of barley and vetch in different nitrogen levels.

In order to evaluate intercropping of barley (Hordeum vulgare) and vetch (Vicia vilosa ler ssp. Desycarpa), two field experiments were conducted on the farm of the University of Tehran, Karaj, Iran in 2004 and 2005. A split plot experiment based on randomized complete block design (RCBD) with four replications was used in this study. Nitrogen was the main factor (0, 45 and 90) and sub plot factor consist of sole wheat and barley and their 50%:50% mixture). Results showed that mixture was more efficient than sole crops (LER < 1). The highest LER occurred when nitrogen was not applied. Intercrops absorb 12% more light than sole crops and the light use efficiency was higher in mixture than sole crops. Means of light use efficiency in pure barley, pure vetch and the mixture were 1.67, .73 and 1.75 g.Mj-1, respectively. Different cropping systems had a significant t effect on leaf area index (P < 0.05) and area of leaf was greater at flowering stage in mixture. It can be concluded that intercropping was more efficient than sole cropping especially under low input conditions for the region. Of course more investigation is recommended.