Changes in soil properties under mechanical stress significantly influence the emergence and growth of crops, with different crops responding differently to these changes. To explore the impact of different soil compaction states on crop growth, field experiments were conducted in 2022 and 2023 in sandy loam soil in Manitoba, Canada. The crops (canola and soybean) were planted under three compaction levels created by a seeder’s press roller: no press roller (P0), one pass of the press roller (P1), and two passes of the press roller (P2). Soil mechanical properties and plant growth were measured for each treatment. The results indicated that soil shear strength increased significantly with each level of compaction from P0 to P1 and from P1 to P2, while soil surface resistance remained largely unaffected. Interestingly, soybean and canola responded differently to soil compaction. Soybeans showed no significant changes in emergence speed or final plant population across the three treatments. Conversely, canola exhibited over a 50% increase in emergence speed and more than a 100% increase in final plant population with either one (P1) or two passes (P2) of the press roller, compared to the no press roller (P0) treatment. These findings provide valuable guidance for agricultural producers and engineers in adjusting the down pressure of seeder press wheels when planting different crops.

Mechanical weed-control methods using autonomous weeding machines provide an option for farmers to reduce the use of herbicides while efficiently dealing with weed issues. However, there is limited knowledge regarding the effects of advanced mechanical weed control technology on soil bacterial communities in paddy fields. In this study, a field experiment was conducted in southern China in 2021. High-throughput 16S rRNA gene sequencing was employed to sequence bacterial communities in soil samples under three treatments: mechanical weeding, chemical weeding, and no weeding. The objective was to investigate the impact of different weed-control methods on the diversity, composition, and co-occurrence patterns of soil bacteria. While mechanical weed-control method did not significantly alter bacterial alpha diversity, it specifically increased the relative abundance of the Bacteroidota phylum. Co-occurrence network analysis further showed that mechanical weed-control treatment enhanced network complexity and the proportion of positive interactions among bacteria, likely due to the physical intertillage effect of the weeding machinery. Our one-year study indicates that mechanical weed control can promote beneficial shifts in soil bacterial interactions without reducing diversity, offering a novel microcosmic perspective for selecting appropriate weed-control methods in agricultural management and sustainability of soil ecosystems.

Introduction: The current nitrogen fertilizer application methods during rice ( Oryza sativa L .) transplanting have many problems. To address the problems, a new method, the full root-zone fertilizer application method (RF), was applied during transplanting. Methods: To investigate the impact of the RF method compared with other fertilizer methods on rice productivity, three repeated experiments were carried in different sites in South China from 2022 to 2023, involving four treatments being four fertilizer application methods: no nitrogen fertilizer applied throughout whole growth cycle (C), RF, deep-side fertilizer application (DF), and manually broadcasting fertilizer application (BF). All treatments applied 100 kg ha ^-1 N during transplanting except C. Results and Discussion: The experiment results demonstrated that at the tillering stage, the RF method significantly enhanced rice root characteristics over the BF method, with increases of 24.41% in average root length, 34.93% in diameter, and 25.22% in total root surface area. The tiller number and the antioxidant enzymes activity under the RF method were significantly higher than the DF and BF methods during the rice growth period. The rice yield under RF method increased 13.87% to 33.41% compared with BF and DF methods. This increase was associated with superior performance in effective panicle number and seed setting rate at maturity. The RF method also significantly enhanced nitrogen use efficiency (NUE) compared to other methods, by reducing nitrogen loss and improving plant nitrogen uptake. Additionally, the RF method increased net income by 31.77% to 45.33% over the DF and BF methods by raising the total rice value.