Evaluation of different crop rotation schemes for organic common bean production under mild-winter climatic conditions

An experiment with different rotation schemes was established at the facilities of the Laboratory of Vegetable Crops at the Agricultural University of Athens. This experiment aims to contribute to the establishment of sustainable crop rotation schemes for organic common bean production under mild-winter climatic conditions that optimize N availability to the crop and maximize yield. The experiment was conducted during autumn 2017 to summer 2018 and repeated the following year (autumn 2018 to summer 2019). In particular, during the winter cultivation periods of 2017-2018 and 2018-2019 the experimental field was cultivated with broccoli under organic (a) or conventional (b) farming systems, faba bean as green manure (c), while non-cultivated plots (d) served as the control treatment. During the respective spring-summer cultivation period (2017-2018 and 2018-2019), the winter crops (a), (c) and (d) were followed by common bean treated according to organic farming practices, while the crop (b) was followed by conventional farming of common beans. The results indicated that the incorporation of faba bean to the soil as green manure enhanced the N availability and the fresh pod yield in the following crop of common bean in both years. The lowest yield was recorded in the organically-grown common bean when the preceding winter crop was organically grown broccoli in both cultivation periods. However, the lowest N availability in the soil was recorded in the plots of organically treated common bean which were in fallow during the preceding winter.