Crop productivity is typically affected by various soil–plant factors systematically as they influence plant photosynthesis, soil fertility, and root systems. However, little is known about how the productivity of legumes is related to crop rotation systems. The objectives of this study were to determine the effect of rotation systems on legume productivity and the relationships among legume productivity and soil–plant factors. Three annual legumes – chickpea (Cicer arietinum L.), pea (Pisum sativum L.), and lentil (Lens culinaris Medikus), were included in various diversified rotation systems and compared with legume monoculture in the 8-year rotation study. Soil N and water conditions, and canopy and root systems were evaluated at the end of 8-year rotation in the semiarid Canadian prairies. Results showed that diversified rotation systems improved leaf greenness by 4%, shoot biomass by 25%, nodule biomass by 44%, and seed yield by 95% for chickpea and pea, but such effects were not found for lentil. Pea monocultures increased root rot severity by threefold compared with diversified rotations, and chickpea monoculture increased shoot rot severity by 23%, root rot severity by 96% and nodule damage by 219%. However, all the legume monocultures improved soil N accumulation by an average 38% compared to diversified systems. Pea and chickpea displayed considerable sensitivity to plant biotic stresses, whereas lentil productivity had a larger dependence on initial soil N content. The 8-year study concludes that the rotational effect on legume productivity varies with legume species, the frequency of a legume appearing in the rotation, and the integration of relevant soil and plant indices.
Bibliographical noteFunding Information:
The authors thank Lee Poppy and Limin Luan for their excellent technical assistance with field operation, Yining Niu for suggestions on experimentation, and Jianling Fan, Chen Gu, and Hu Wang for suggestions on data interpretation and manuscript preparation. Funding. This study was supported by the MOE-AAFC Ph.D. Research Program (Ministry of Education, China and Agriculture and Agri-Food Canada), the National Natural Science Foundation of China (Grant Nos. 31460337, 31660373, and 31761143004), and the Education Department of Gansu Province, China (Grant No. 2017C-12).
© 2018 Li, Liu, Zhang, Huang, Coulter, Woodburn, Li and Gan.
- Biotic stress
- Cropping system
- Sustainable agriculture