This peanut-sorghum intercropping study examined the effects of peanut habit of posture (one erect and one semi-erect accession) on dwarf sorghum growth and yield over two years under field conditions. In northern China, the dwarf sorghum ( Sorghum bicolor [L.] Moench) is an important and widely planted industrial crop for ethanol fermentation. Substantial efforts are in progress to reduce the negative environmental impacts arising from sorghum monocultures and other conventional farming practices. Intercropping, especially with nitrogen-fixing legumes, was identified as one of the effective and sustainable agricultural practices for maintaining productivity while minimizing ecological impacts. In this study, the intercropping of a dwarf sorghum cultivar with peanuts (two accessions) increased the sorghum yield over two crop cycles. Relative to peanuts planted in monocultures, the intercropping process with sorghum generally reduced peanuts’ yield. Specifically, intercropping lowered the total dry matter, yield, and leaf net photosynthetic rates (Pn) in both peanut accessions. Conversely, in the semi-erect peanut-sorghum system, the total seed yield of the peanut-sorghum system increased by 19.5% in 2021 and 21.2% in 2022, resulting in a land equivalent ratio (LER > 1), whereas the erect peanut-sorghum system failed to deliver better outcomes (LER < 1). Interestingly, the semi-erect habit mitigated intercropping-induced yield losses in peanuts while conferring a significant yield advantage to sorghum compared to the erect system. From the photosynthesis perspective, the intercropped peanut plants had lower quantum yields of photosystems I (PSI) and II (PSII) than the monocultured peanuts; and this inhibition was less pronounced in the semi-erect peanuts. Additionally, the cyclic electron flow (CEF), proton gradient (∆pH), and non-photochemical quenching were higher in intercropped peanuts than in monocultured peanuts. The increased foliar CEF and ΔpH plausibly helped the semi-erect type peanut to alleviate photoinhibition and growth reduction in the peanut-sorghum intercropping system. These enhanced photoprotective mechanisms (increased CEF and ΔpH) facilitated photosynthetic acclimation in the semi-erect peanuts, highlighting the value of habit-specific selection for optimizing sorghum-peanut intercropping. • Intercropping with peanuts increased dwarf sorghum yield over two cycles. • Intercropping lowered peanut yield attributed to carbon-assimilation limitation. • Semi-erect peanut varieties mitigated yield loss during intercropping. • High CEF and ΔpH in semi-erect peanuts helped to alleviate photoinhibition.

Cover cropping has the potential to enhance the sustainability of cropping systems across temperate regions. However, poor establishment of cover crops (CCs), often driven by unfavorable weather conditions, remain a major barrier to their adoption. Sowing CC mixtures may mitigate the risks of poor establishment compared to pure stands, thereby lowering spatio-temporal variability in biomass production, which is critical for consistent ecosystem service provision. Yet, it is unclear whether CCs establish more successfully in mixtures than in pure stands, and whether a better establishment results in greater biomass production that enhances ecosystem services. We aimed to: i) analyze seedling emergence dynamics, final emergence rates, and emergence vigor (i.e., speed of emergence) in CC mixtures vs. pure stands; ii) determine the relationship between seedling establishment success and final biomass production; and iii) evaluate the effect of CC mixtures vs. pure stands on soil cover, weed suppression, nitrogen (N) catch crop, and N green manure services. A 2-year field experiment (2020–2022) was conducted in Southwestern France, testing 11 pure stands and six two-species mixtures of brassicas, legumes, and grasses. CCs were sown in autumn and grown for eight months, with a fallow treatment as control. Data were analyzed using analysis of variance. Significant intra- ( p < 0.001) and inter-annual ( p < 0.001) variability was observed in CC seedling emergence dynamics. Brassica CCs showed the highest emergence vigor (77 ± 21°Cd), and their establishment success was positively correlated with final biomass yield (0.4 ± 0.2–8.6 ± 0.6 t.ha −1 ; r = 0.61, p < 0.001). In contrast, legumes, such as faba bean, showed the lowest emergence vigor (147 ± 52°Cd), and their biomass yield (3.1 ± 0.1–6.8 ± 0.4 t.ha −1 ) depended mainly on post-establishment climatic conditions. Seedling emergence vigor and establishment success did not differ significantly between CC mixtures and pure stands. Single species CC yielded more variable biomass between years, mixtures produced more stable yields (2.1 ± 0.1–9.9 ± 0.3 t.ha −1 ). Soil cover was similar between CC pure stands (75.0 ± 0.0–100.0 ± 0.0 %) and mixtures (66.7 ± 5.3–100.0 ± 0.0 %), whereas poor establishment reduced soil cover (25.0 ± 7.9–50 ± 0.0 %). All CCs effectively suppressed weeds (up to 100 % reduction in biomass) and supplied N through scavenging and/or green manuring (up to 203 ± 18 kgN.ha −1 ) compared to fallow. In systems dominated by monocultures or short rotations under high-input management and climatic uncertainty, Brassicaceae-Fabaceae mixtures represent a promising option to ensure good establishment, stable biomass production, and delivery of key ecosystem services. • Brassica CCs had the highest seedling vigor; legumes showed species-specific, contrasting responses. • Brassica CC biomass relied on seedling establishment quality; legumes were less dependent on it. • Inter-annual variability in biomass production was lower in CC mixtures than in pure stands. • CC mixtures overyielded compared to pure stands, but transgressive overyielding was rare. • Both CC mixtures and pure stands effectively suppressed weed biomass.