The veterinary antibiotics contamination in agroecosystems is a substantial problem globally. However, little is known about their toxicity to crops, especially in wheat. This study evaluated the phytotoxic effects of the two most representative antibiotics, namely oxytetracycline (OTC) and enrofloxacin (ENR), on seed germination, seedling growth, root elongation and antioxidant status in wheat, and investigated the response of abscisic acid (ABA) to antibiotic stress and its underlying mechanism. The results showed that OTC and ENR under the experimental concentrations (5, 10, 20, 40 and 80 mg·L^-1) had no influence on seed germination of wheat. The reduced root length, fresh weight and surface area were observed when the concentrations of OTC and ENR were higher than 10 mg·L^-1 and 5 mg·L^-1, respectively. High concentrations (＞40 mg·L^-1) of antibiotics dramatically decreased the root length, fresh weight, root numbers and surface area as well as the number of stele cells and stele area. The activity of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD), and malondialdehyde (MDA) content in shoots and roots were increased with the increasing OTC and ENR concentrations. High concentrations (＞40 mg·L^-1) of antibiotics improved ABA content and enhanced the transcription levels of genes related to ABA biosynthesis (TaNCED1 and TaNCED2) and metabolism (TaABA8'OH1-A and TaABA8'OH2-A) in shoots and roots of wheat seedlings. Wheat seedlings had relatively strong sensitivity to low concentration (5 mg·L^-1) of ENR. These results suggest that OTC and ENR modulate root development and seedling growth by regulating ABA level and antioxidant defense system in wheat.

Wheat (Triticum aestivum L.) is a staple crop worldwide, and its yield has improved since the green revolution, which was attributed to chemical nitrogen (N) fertilizer application. An experiment was conducted to set seven nitrogen application levels of N0, N90, N120, N150, N180, N210 and N240 kg ha⁻¹ before sowing. The results showed that grain yield under the nitrogen rate of N210 kg ha⁻¹ was significantly increase the water intake during jointing to anthesis, Soil water storage of dryland wheat in fallow period was higher than water consumption in jointing stage and the leaf area index at anthesis, the tiller percentage rate, the jointing-anthesis, and nitrogen accumulation were closely related to yield and its components. Nitrogen fertiliser rate N150 kg ha⁻¹ significantly increased dry matter buildup from jointing to flowering in dryland wheat compared to N fertiliser rate N210 kg ha⁻¹. The rise of nitrogen application rate, there were no significant variance in nitrogen accumulation of Stem + leaf sheath and cob + glume at maturity, respectively. N fertiliser rate N210 kg ha⁻¹ compared to N180 kg ha⁻¹ significantly reduced grain gliadin content in dryland wheat, respectively. Wheat crops under N210 kg ha⁻¹ could achieve both high NUE and grain yield simultaneously with only moderate N fertilizer in South Shanxi, China.

The restoration of soil fertility and microbial communities is the key to the soil reclamation and ecological reconstruction in coal mine subsidence areas. However, the response of soil bacterial communities to reclamation is still not well understood. Here, we studied the bacterial communities in fertilizer-reclaimed soil (CK, without fertilizer; CF, chemical fertilizer; M, manure) in the Lu’an reclamation mining region and compared them with those in adjacent subsidence soil (SU) and farmland soil (FA). We found that the compositions of dominant phyla in the reclaimed soil differed greatly from those in the subsidence soil and farmland soil (p < 0.05). The related sequences of Acidobacteria, Chloroflexi, and Nitrospirae were mainly from the subsided soil, whereas those of Alphaproteobacteria, Planctomycetes, and Deltaproteobacteria were mainly derived from the farmland soil. Fertilization affected the bacterial community composition in the reclaimed soil, and bacteria richness and diversity increased significantly with the accumulation of soil nutrients after 7 years of reclamation (p < 0.05). Moreover, soil properties, especially SOM and pH, were found to play a key role in the restoration of the bacterial community in the reclaimed soil. The results are helpful to the study of soil fertility improvement and ecological restoration in mining areas.

The Loess Plateau in China has long grappled with issues such as chronic soil erosion, poor soil structure, and diminished organic matter. Soil organic carbon plays a crucial role in enhancing soil fertility, and fertilization is a key tool that influences it. In a comprehensive field experiment, we examined five fertilization methods: no fertilization (CK); traditional fertilization used by local farmers (FP); nutrient-balanced fertilization with nitrogen, phosphorus, and potassium (OF); chemical fertilizers used in conjunction with organic fertilizers (OFM); and chemical fertilizers paired with bio-organic fertilizers (OFB). Our findings revealed that the OFM and OFB treatments were the most effective, explaining 84.35% and 81.26% of the variation in soil carbon sequestration, respectively. Further, the OF, OFM, and OFB treatments demonstrated superior effectiveness compared with the FP treatment in enhancing the soil carbon fractions. However, these fertilization patterns did not significantly alter the active-to-inert carbon ratio of the soil. OF, OFM, and OFB treatments enhanced the stability of soil carbon pools more than FP treatment. In structural equation modeling, factors such as microbial biomass nitrogen and phosphorus, soil pH, and β-N-acetyl glucosidase indirectly exhibited a limiting effect on the carbon pool stability index (CPSI), while β-glucosidase displayed an indirect positive correlation with the carbon fractions. In contrast, dissolved organic carbon, low-molecular-weight organic carbon, high-molecular-weight organic carbon, and crop yield demonstrated direct positive correlations with the CPSI. Consequently, both a balanced application of chemical fertilizers and the combination of organic and chemical fertilizers were effective in enhancing and sustaining the soil’s organic carbon content, thereby contributing to soil fertility stability. To this end, this study can inform the efficient selection and use of fertilizers, improving crop yield and soil carbon content.