Response of Wheat and Faba Bean to Intercropping and Tillage System on a Mediterranean Rainfed Vertisol

The sustainability of agricultural systems can be improved by practices such as intercropping or no tillage. Such practices have not been evaluated for wheat–faba bean cropping systems on a Vertisol in the rainfed Mediterranean region. A 3-yr study (2014–2015, 2015–2016 and 2016–2017) was conducted to determine the effects of tillage systems (reduced tillage and no tillage) on wheat (Triticum aestivum L.)–faba bean (Vicia faba L.) intercrop and sole crop performance under a dryland rotation system with sunflower (Helianthus annuus L.) rotation. Wheat was intercropped with faba bean arranged 2:1 row. The field experiment was designed in a split plot randomized block with tillage system in main plot and cropping system in sub-plot with four replications. The land equivalent ratio of the grain yield was greater than 1, indicating a more efficient use of land by intercropping. No tillage improved the grain yield compared to reduced tillage by 65, 10 and 32% in the cultivation of wheat, faba beans and sunflower, respectively. The grain yield obtained with the intercropping system was higher than that with the sole cropping system only in the faba bean crop. The cropping system was not influenced by the tillage systems. The soil–plant analyses development (SPAD) values were lower for the intercropped wheat, suggesting a lower bioavailability of N in this cropping system. However, intercropping could be highly beneficial compared to planting wheat alone since higher grain yields are achieved even without the application of N fertilizer.