Recently, biochar (B) and vermicompost (V) have been widely used as amendments to improve crop productivity and soil quality. However, the ameliorative effects of biochar and vermicompost on the continuous cropping of pepper under open-air conditions, particularly in the karst areas of southwestern China, remain unclear. A field experiment was conducted to study the effects of biochar and vermicompost application, alone or in combination, on the yield, quality, nutrient accumulation, fertilizer utilization, and economic benefits of continuous pepper cropping from 2021 to 2022. The experiment included six treatments: CK (no fertilizer), TF (traditional fertilization of local farmers), TFB (TF combined with biochar of 3000 kg·ha^-1), TFV (TF combined with vermicompost of 3000 kg·ha^-1), TFBV1 (TF combined with biochar of 1500 kg·ha^-1 and vermicompost of 1500 kg·ha^-1), and TFBV2 (TF combined with biochar of 3000 kg·ha^-1 and vermicompost of 3000 kg·ha^-1). Compared with the TF treatment, biochar and vermicompost application alone or in combination increased the yield of fresh pod pepper by 24.38–50.03% and 31.61–88.92% in 2021 and 2022, respectively, whereas the yield of dry pod pepper increased by 14.69–40.63% and 21.44–73.29% in 2021 and 2022, respectively. The application of biochar and vermicompost reduced the nitrate content and increased the vitamin C (VC) and soluble sugar content of the fruits, which is beneficial for improving their quality. Biochar and vermicompost application alone or in combination not only increased nutrient uptake but also significantly improved agronomic efficiency (AE) and recovery efficiency (RE). In addition, although the application of biochar or vermicompost increased production costs, the increase in yield improved net income (ranging from 0.77 to 22.34% in 2021 and 8.82 to 59.96% in 2022), particularly in the TFBV2 treatment. In conclusion, the use of biochar and vermicompost amendments had a positive effect on the productivity and economic benefits of continuous pepper cropping, and the co-application of biochar and vermicompost could be an effective nutrient management strategy for the continuous cropping of pepper in the karst mountain areas of southwest China.

A high-quality canopy architecture is central to obtaining high crop yields. A field experiment was carried out at the Wuqiao Experimental Station from 2015 to 2019 under four irrigation schemes (W₀, no irrigation after sowing; W₁, 75 mm irrigation at jointing stage; W₂, 75 mm irrigation at jointing and anthesis stages, respectively; W₃, 75 mm irrigation at tillering, jointing and anthesis stages, respectively) to investigate the canopy structure, canopy apparent photosynthesis (CAP), canopy temperature (CT), yield and water use efficiency (WUE). The results showed that increasing irrigation times improved the leaf area index (LAI), non-leaf area index (NLAI) and light interception (LI) of the spike and total canopy but decreased the canopy temperature (CT) after anthesis. The CAP in the W₃ treatment was consistently lower than that in the W₁ treatment, suggesting lower effective utilization of light energy under the W₃ treatment. Increasing irrigation times improved wheat yield, but the W₂ treatment had no significant difference in yield compared to the W₃ treatment. In addition, the W₁ and W₂ treatments had higher WUEs. The CT, organ temperature and LI were closely positively associated with each other, but they were all strongly negatively related to the yield. Overall, the W₂ treatment was the best irrigation scheme for constructing a reasonable canopy architecture for winter wheat, obtaining more efficient water use and yield in the North China Plain (NCP). CT and organ temperature can be used as proxy parameters to estimate the canopy structure.

Drought stress inhibits quinoa ( Chenopodium quinoa Willd.) seed germination and seedlings growth, significantly affecting yield and quality. Nevertheless, the molecular mechanisms underlying quinoa’s drought stress response are not yet fully elucidated. Therefore, a multi-omics analysis of the response to drought stress was conducted using two drought-resistant quinoa varieties (LL1 and LQ18) subjected to normal (CK) and severe (DS2, 20% PEG-6000) drought conditions. Drought stress exerted no statistically significant impact on germination rate, germinative force, and germination index for LQ18, but DS2 treatment reduced these germination indicators for LL1. Concomitantly, DS2 treatment notably decreased seedlings height, hypocotyl length, radicle length, dry and fresh weight, especially for LL1. Multi-omics analyses revealed that DS2 treatment markedly downregulated genes related with starch and sucrose metabolism and galactose metabolism during the radicle emergence stage, whereas these pathways were subsequently upregulated at the cotyledon expansion stage. Thus, the starch and sucrose content increased at the two stages, while glucose content decreased at radicle emergence stage but increased at cotyledon expansion stage. The low glucose concentration at radicle emergence stage likely suppressed abscisic acid (ABA) biosynthesis, resulting in no significant change in the abundance of the differentially accumulated metabolites (DAM) of ABA. The hormonal balance was significantly altered, with the gibberellins (GAs)/ABA ratio being significantly lower in LL1 under DS2, while it was slightly up-regulated in LQ18. In addition, DS2 treatment induced genes expression of antioxidant systems, in which soluble sugars, proline, and malondialdehyde content accumulated, and raffinose, stachyose, trehalose, glutathione, kaempferol, and quercetin abundance increased, especially for LQ18. Collectively, the findings of this study contribute to a deeper understanding of the drought tolerance mechanisms of quinoa, thereby providing a theoretical foundation for future research on quinoa’s drought resistance.