Seed priming with silicon (Si) is an efficient and easy method to regulate plant tolerance against different abiotic stresses. A pot experiment was conducted to examine the Si-mediated changes in oxidative defense and some vital physio-biochemical parameters of maize under a limited water supply. For this purpose, two maize varieties (Pearl and Malka) with different Si priming treatments (0, 4 mM, 6 mM) were grown under a control and 60% field capacity for three weeks. At 60% field capacity, significant reductions in plant growth attributes and chlorophyll contents were recorded compared with the control. The negative effects of drought stress were more severe for Malka compared with Pearl. Drought stress increased the malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) contents, altered the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), and triggered the accumulation of soluble sugars, glycine betaine, proline, and phenolics contents. Nevertheless, seed priming with silicon at 4 or 6 mM was effective in alleviating the detrimental effects of drought stress in both cultivars. Si priming particularly at 6 mM significantly enhanced the shoot and root lengths as well as their biomass and improved the levels of photosynthetic pigments. Moreover, Si treatments enhanced the activities of antioxidant enzymes (SOD, POD, and CAT) while it reduced the MDA and H₂O₂ contents in both cultivars under stress conditions. In crux, the present investigation suggests that Si priming mitigates the harmful effects of drought stress and contributes to the recovery of maize growth.

To evaluate atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) ecotoxicology in soil, the effect of atrazine on the activity of antioxidative enzymes (superoxide dismutase [SOD], catalase [CAT], and guaiacol peroxidase [POD]) was investigated in Vicia faba roots. Tissues from each treatment were collected on the days 7, 14, 21, and 28. Compared with the controls, SOD activity in V. faba roots was stimulated by the 2.5 mg/kg treatment and inhibited by the 5 and 10 mg/kg treatments, and CAT and POD activities in the 10 mg/kg treatment were inhibited on the whole. The Olive tail moments of single-cell gel electrophoresis of root cells were enhanced after treatment with different doses of atrazine on days 7, 14, 21, and 28, and significant differences were found compared to the controls. In conclusion, atrazine induces oxidative stress and DNA damage on V. faba.

Application of controlled-release urea (CRU) improves crop yield and nitrogen use efficiency (NUE) compared with conventional urea. However, the effectiveness of CRU differs with fertilization placement. A two site-year field experiment was carried out in fluvo-aquic soil in central China to study the effects of two N sources (CRU and urea) and three fertilization placements (band application between two corn rows at 0, 5, and 15 cm soil depths) on fresh ear yield and NUE of sweet corn. The soil inorganic N (NO₃⁻-N and NH₄⁺-N) concentrations at the soil layers of 0–20 cm and 20–40 cm, root morphology characteristics and leaf physiological functions were also measured during the sweet corn growth period. Results showed that the deep placement of CRU at 15 cm soil depth significantly increased the sweet corn fresh ear yield, total N uptake, and NUE by 6.3%–13.4%, 27.9%–39.5%, and 82.9%–140.1%, respectively compared with CRU application at 0 cm depth. Deep placement of CRU at 15 cm also increased the root morphology traits, gas exchange attributes, and soil NO₃⁻-N and NH₄⁺-N concentrations in 0–20 cm and 20–40 cm layer, especially during later crop growth stages. However, the different N placements exerted non-significant effects on NUE and fresh ear yield when urea was applied as the N source. In crux, deep CRU placement instead of urea at 15 cm depth can effectively improve fresh ear yield and NUE of sweet corn in fluvo-aquic soil because of higher root growth, better leaf physiological functions and increased availability of soil NO₃⁻-N and NH₄⁺-N.

Fusarium head blight (FHB) disease severely impacts wheat production and quality. Silica nanoparticles (SiNPs) are demonstrated as an eco-friendly option for disease management, but the specific mechanisms behind their ability to confer disease resistance in wheat have not been adequately characterized. This study evaluates the impact of SiNP200 on the resistance of wheat to FHB. Scanning electron microscope observation showed that SiNPs form a physical barrier on the surface of wheat leaves. Pathogenicity tests indicated foliar application of SiNP200 can protect wheat against F. graminearum, resulting in a significant reduction of lesion length by 27.7%, but in vitro cultivation showed that SiNP200 had no impact on pathogen growth. Antioxidant enzyme activity analysis showed that SiNP200 had little effect on H₂O₂ contents, POD, and CAT activities under non-stress conditions, but under F. graminearum infection conditions, SiNP200 increased POD and SOD activities while decreased CAT and DHAR activities, and GSH content. Histochemical staining indicated that SiNP200 decreased ROS accumulation, thus reducing oxidative damage. Meanwhile, SiNP200 decreased MDA and Pro contents. Furthermore, SiNP200 increased SA response marker genes (TaPR1a, TaPR2 and TaPR5) expression levels and SA content, contributing to the enhanced wheat resistance to FHB. Summarily, SiNP200 improve wheat resistance to FHB, thereby providing a theoretical basis for SiNP200 application to control this disease.

The gleyed paddy soils in subtropical China, characterized by poor structure, high reductive substances, and low fertility, pose challenges to sustainable agriculture. This study investigates the improvement effects of applying rapeseed green manure in combination with biochar or vermicompost through field experiments, aiming to provide a theoretical basis for the organic improvement of gleyed paddy soils. The experiment included four treatments: control (CK), rapeseed green manure (GM), GM + biochar (GMB), and GM + vermicompost (GMVC). Soil physicochemical properties, aggregate stability, and fungal communities were analyzed after rice harvest. GM significantly increased the total nitrogen (TN) content in the 0–10 cm soil layer and decreased the Fe²⁺ and total glomalin-related soil protein (T-GRSP) contents. GMVC further increased the pH value, available potassium (AK) content, and Shannon index in the 0–10 cm soil layer, decreased the available phosphorus (AP) content, and increased the proportion of macro-aggregates (>2000 µm) and decreased the fractal dimension (D) in the 10–20 cm soil layer. Compared with GMVC, GMB more significantly increased the soil organic carbon content and regulated the ratio of EE-GRSP/T-GRSP in the 0–10 cm soil layer. Fungal community analysis showed Ascomycota dominance. Pearson analysis showed Westerdykella enrichment significantly correlated with reduced T-GRSP. Monte Carlo tests identified pH and SOC as key factors shaping fungal communities. The GMB strategy mitigates reductive stress, enhances nutrient availability, and activates microbial functionality. These findings offer insights and frameworks for sustainable soil management in subtropical rice agroecosystems.