Field Crop 2024, Vol.7, No.2, 58-69 http://cropscipublisher.com/index.php/fc 63 maintain productivity and reduce the reliance on mineral fertilizers (Iannetta et al., 2016). Another example is the use of legume-based cropping systems in temperate agroecosystems, which has been shown to improve nitrogen use efficiency and overall sustainability (Anglade et al., 2015; Rodriguez et al., 2020). These case studies underscore the potential of legumes to contribute significantly to sustainable agricultural practices through enhanced nitrogen fixation and improved soil fertility. Figure 3 Systemic responses of the rhizobium-legume holobiont to plant N deficit (Adopted from Lepetit and Brouquisse, 2023) Image caption: Various steps of the regulatory loop are indicated in blue. A local suppression of SNF may be obtained artificially (by replacing locally air by a mixture Ar/O2 80/20 v/v) or as the result of abiotic stresses. The local inhibition of symbiosis in the roots exposed to these conditions results in a partial decrease of the whole plant SNF. As the whole plant N demand is not fully satisfied, the systemic signaling promoting symbiosis is activated, resulting in the formation of new nodules on the other roots not exposed to the constraint. In mature nodules of these roots, the Ndeficit systemic signaling results in a strong increase in nodule sucrose and organic acid levels associated with nodule expansion. This increase in nodule biomass is associated with higher levels of SNF in roots not exposed to the local constraint that may compensate the plant N deficit (Adopted from Lepetit and Brouquisse, 2023) 6 Environmental Impact 6.1 Reduction of synthetic fertilizer use through BNF Biological nitrogen fixation (BNF) in legumes significantly reduces the need for synthetic nitrogen fertilizers in agricultural systems. Legumes, through their symbiotic relationship with rhizobia, can fix atmospheric nitrogen, making it available to the plant and subsequently to the soil. This process not only enhances soil fertility but also reduces the dependency on synthetic fertilizers, which are often costly and environmentally damaging (Iannetta et al., 2016; Kessel and Hartley, 2000; Kebede, 2021). Intercropping legumes with cereals has been shown to increase the efficiency of nitrogen use, further reducing the need for synthetic fertilizers (Rodriguez et al., 2020; Jensen et al., 2020). This practice can lead to a reduction in the global requirement for synthetic nitrogen fertilizers by approximately 26% (Jensen et al., 2020).
RkJQdWJsaXNoZXIy MjQ4ODY0NQ==