Clarifying the effect of postponing nitrogen application on yield under nitrogen reduction is of great importance for increasing yield and optimizing the nitrogen application system of Tartary buckwheat. A two-year field experiment with six nitrogen treatments, including a conventional fertilizer application pattern (CK) and five treatments under 20% nitrogen reduction, with 0% (NP1), 10% (NP2), 20% (NP3), 30% (NP4), and 40% (NP5) postponed of nitrogen amounts, topdressing at the flowering stage, was conducted on the high-yielding Tartary buckwheat variety ‘Daku 1’. Compared with CK, the NP4 treatment significantly increased osmotic adjustment substance content, antioxidant enzyme– and nitrogen metabolism–related activities, dry matter accumulation, and yield. Compared with CK, the NP2, NP3, NP4, and NP5 treatments increased yield by 8.09%, 22.06%, 66.91%, and 31.62%, respectively, whereas the NP1 treatment decreased yield by 33.09%. In summary, appropriately postponing nitrogen application can improve the yield of Tartary buckwheat by improving root activity, delaying leaf senescence, and coordinating nitrogen metabolism balance. Under the conditions of this two-year single-site field study, the NP4 treatment showed promise as a nitrogen-saving strategy for improving Tartary buckwheat yield; however, further validation across different environments, soil types, and cultivars is needed before broad production recommendations can be made.
Magnetite is widely recognized as an excellent adsorbent for mitigating aqueous arsenic (As) contamination; however, the influence of aqueous Fe(II) and organic acids on As retention under oxic conditions remains poorly understood. Here, we examined the effects of 10 mM Fe(II) and 10 mM acetic acid on the adsorption kinetics of As(III) and As(V). Magnetite preferentially adsorbed As(V) over As(III), with partial structural Fe dissolution, contributing to enhance As adsorption. Adsorption kinetics differed markedly among treatments (control, Fe(II), acetic acid, and Fe(II) + acetic acid). In the As(V) system, the adsorption was rapid and appeared to reach a near steady state by the first sampling point at 24 h, with Fe(II) addition-either alone or with acetic acid-promoting nearly complete As(V) adsorption (100% of added As) compared with the control (35% of added As). Conversely, acetic acid alone decreased As(V) sorption (29% of added As). In the As(III) system, the adsorption pattern was more complex due to concurrent As(III) oxidation. Fe(II) addition enhanced As(III) adsorption but decreased As(V) adsorption, whereas combined Fe(II) + acetic acid decreased As(III) but increased As(V) adsorption. Acetic acid promoted As(III) oxidation and reduced overall As adsorption. Overall, Fe(II) enhanced both As(V) and As(III) immobilization by magnetite under oxic conditions, whereas acetic acid increased As(III) oxidation but reduced total As retention. Our findings highlight the interactive effects of Fe(II) and organic acids on As-magnetite interactions, r
To explore the feasibility of adding rosemary to goose feed, we compared the effects of basal diet (CON), 0.02 % rosemary extract (RE) and 15 % rosemary residue (RR) feed on goose meat quality, nutritional composition, antioxidant capacity and storage performance. Compared with CON, the RR and RE significantly increased levels of muscle glutathione peroxidase (GSH-Px), essential amino acid (EAA) and polyunsaturated fatty acid (PUFA) (P < 0.05), while shear force, crude fat, malondialdehyde, and saturated fatty acid levels were significantly reduced (P < 0.05). Addition-ally, the RR group had lower a* value of muscle, total antioxidant capacity, GSH-Px, EAA and PUFA levels than RE group (P < 0.05). Notably, the total viable count in RE group was significantly reduced (P < 0.05). Overall, dietary RE at 0.02 % simultaneously upgrades goose meat quality, nutritional value and storage stability, whereas 15 % RR gives moderate but still favourable changes. Consequently, RE is recommended for high-quality goose production, whereas RR can be utilized as an economical, partial substitute for conventional feed ingredients.
