Agriculture must balance productivity with greenhouse gas emissions, biodiversity, and resource concerns. This study examined how tillage (conventional, CT; minimum, MT), nitrogen fertilisation (0–221 kg N ha⁻¹), and herbicide rates (0–100%) interactively affected soil CO2 emissions, vegetation vigour, and weed diversity in maize production during 2022. A factorial experiment was conducted on a 1 ha with 40 plots monitored soil temperature, moisture, penetration resistance, normalised difference vegetation index (NDVI), weed diversity (Simpson’s Index), and CO2 emissions (closed-chamber method). Minimum tillage increased soil water retention (9.3 ± 6.5% vs. 5.4 ± 4.3%), soil temperature (28.0 ± 1.5), and compaction (0.6 ± 0.3 vs. 0.1 ± 0.0 MPa), while enhancing weed diversity (0.53–0.80 vs. 0.38–0.67). MT produced higher CO2 emissions than CT, especially at 147 kg N ha⁻¹ (49.9 ± 15.7 vs. 29.1 ± 11.6 μmol m⁻² s⁻¹), peaking under MT-147 kg N ha⁻¹-H75 (79.4 ± 1.2 μmol m⁻² s⁻¹). NDVI responses varied between tillage systems; under CT, vegetation vigour peaked at 75% herbicide application, while under MT vegetation was more responsive to nitrogen and more sensitive to herbicide, highlighting nitrogen × herbicide interaction trade-offs. Overall, MT enhanced water conservation and weed diversity but increased short-term CO2 emissions. This study reports first-year, site-specific results from an ongoing multi-year field experiment; therefore, the findings were interpreted as short-term, season-specific responses. This highlights the need for site-specific, climate-smart management that integrates emissions, soil health, biodiversity, and productivity.

Onions (Allium cepa L.) are widely cultivated and consumed vegetable crops around the world. Weed interference is the main limitation to onion production. Onions grow slowly, are short-statured, and are non-branching, which makes them difficult to compete with weeds. The aim of this study was to summarise the literature published between 2020 and 2025 that evaluated the effectiveness of different weed control methods used in onion cultivation using a systematic review following the PRISMA guidelines. Based on the results, pendimethalin and oxyfluorfen were the most used and most effective herbicides. Combining pre- and post-emergence treatments and spraying herbicide mixtures improved weed control efficiency compared with single treatments. Acetolactate synthase (ALS) inhibitors can adversely affect onions and reduce yield, making them unsuitable for use in onion production. Integrated weed management practises, such as combining herbicides with manual weeding and using plant-based extracts, offer a sustainable approach that can reduce reliance on chemicals. Mechanical weed management is not widely adopted in onion production because its application poses numerous challenges. The future direction of weed management should focus on technological advances in mechanical weed control and the development of bioherbicides to reduce reliance on synthetic herbicides.