Weeds seriously affect the yield and quality of crops. Because manual weeding is time-consuming and laborious, the use of herbicides becomes an effective way to solve the harm caused by weeds in fields. Both 5-enolpyruvyl shikimate-3-phosphate synthetase (EPSPS) and acetyltransferase genes (bialaphos resistance, BAR) are widely used to improve crop resistance to herbicides. However, cotton, as the most important natural fiber crop, is not tolerant to herbicides in China, and the EPSPS and BAR family genes have not yet been characterized in cotton. Therefore, we explore the genes of these two families to provide candidate genes for the study of herbicide resistance mechanisms. In this study, 8, 8, 4, and 5 EPSPS genes and 6, 6, 5, and 5 BAR genes were identified in allotetraploid Gossypium hirsutum and Gossypium barbadense, diploid Gossypium arboreum and Gossypium raimondii, respectively. Members of the EPSPS and BAR families were classified into three subgroups based on the distribution of phylogenetic trees, conserved motifs, and gene structures. In addition, the promoter sequences of EPSPS and BAR family members included growth and development, stress, and hormone-related cis-elements. Based on the expression analysis, the family members showed tissue-specific expression and differed significantly in response to abiotic stresses. Finally, qRT-PCR analysis revealed that the expression levels of GhEPSPS3, GhEPSPS4, and GhBAR1 were significantly upregulated after exogenous spraying of herbicides. Overall, we characterized the EPSPS and BAR gene families of cotton at the genome-wide level, which will provide a basis for further studying the functions of EPSPS and BAR genes during growth and development and herbicide stress.

In Northeast China, increasing agricultural activities has led to severe soil compaction, reducing soil aeration and water infiltration capacity. Conservation tillage, through multiple approaches, alleviates this compaction while simultaneously enhancing crop yields and promoting sustainable agricultural production. In light of domestic and international developments, this paper provides a detailed elaboration on conservation tillage (CT) as a sustainable agricultural practice system. It examines its core technical measures, global adoption status, and impacts on soil physicochemical properties. Furthermore, by analyzing the causes and detrimental effects of soil compaction, it proposes approaches and elucidates the significance of using CT to alleviate compaction in black soils. Integrating considerations of its influence on climate change, economic benefits, future development, challenges, and trends, the paper offers a forward-looking perspective.

To address low nitrogen use efficiency (NUE) derived from excessive fertilization in cotton production in the Yellow River Basin, a field study was conducted to evaluate the effects of two planting densities and six nitrogen (N) rate levels. Key results show that a N rate of 225 kg ha⁻¹ optimized root length density and root biomass density. High planting density (105,000 plants ha⁻¹) improved the population-level root traits, photosynthetic radiation interception, and boll number per unit area, though it reduced individual plant root development. Total dry matter peaked at 225 kg ha⁻¹ N, and density increased reproductive dry matter by 7.5–11.9%. Higher N rates reduced reproductive partitioning and root–shoot ratio. While the maximum seed cotton yield (SCY) was 225 kg ha⁻¹, near-maximum yield was achieved at 150 kg ha⁻¹. NUE declined with increasing N, but densification improved agronomic NUE and partial factor productivity by 1.5–6.6% and 3.3–39.3%, respectively. Under the “densification with N reduction” mode, combining a planting density of 105,000 plants·ha⁻¹ with an N rate of 150 kg·ha⁻¹ achieved conventional yield. At the same density, an N rate of 225 kg·ha⁻¹ not only enabled high yield and maintained relatively high NUE but also showed better adaptability to the simplified cultivation mode in Yellow River Basin cotton-growing regions.

Drought is one of the major abiotic stresses limiting soybean production, and its detrimental effects are jointly influenced by stress intensity, duration, and cultivation conditions. To investigate the morphological and physiological regulatory mechanisms by which mepiquat chloride (DPC) alleviates drought stress at the soybean seedling stage, this study used the drought-tolerant soybean cultivar Heinong 44 (H-44) and the drought-sensitive cultivar Heinong 65 (H-65) as experimental materials. Osmotic stress was simulated with 10% PEG-6000 at the V2 stage, and the effects of foliar application of different DPC concentrations (125–500 mg/L) on soybean morphology, biomass allocation, antioxidant systems, and osmotic adjustment capacity were systematically analyzed. The results showed that drought stress significantly inhibited the growth of both soybean cultivars and induced severe oxidative damage. Appropriate DPC concentrations moderately restricted shoot growth to reduce transpiration area while promoting root growth to enhance water acquisition capacity. The optimal DPC concentrations for alleviating drought stress were 200 mg/L for H-44 and 275 mg/L for H-65. Allometric growth analysis indicated that drought disrupted the original root–shoot growth pattern, whereas appropriate DPC concentrations significantly promoted dry matter accumulation in drought-stressed plants and improved root–shoot growth coordination. However, an excessive concentration of DPC (500 mg/L) caused an abnormal deviation in the growth trajectory. In addition, appropriate DPC concentrations synergistically enhanced the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) in leaves and roots under drought conditions; promoted the accumulation of proline (Pro), soluble sugars (Ss), and soluble proteins (Sp); effectively reduced the contents of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂); and protected cell membrane stability. In conclusion, DPC synergistically enhances drought resistance in soybean by reshaping the root–shoot allometric growth configuration and systematically activating physiological defense networks, providing a theoretical basis for chemically regulated cultivation of soybean under stress conditions.

Salt stress is a major abiotic stress limiting soybean production, with the seedling stage being the most salt-sensitive period. Elucidating the growth, ph

Soybean is an important protein source, economic crop, and strategic agricultural product, which is related to nutrition and health, industrial development, and food security. Mepiquat chloride (MC) can influence yield, but its effectiveness depends on application timing and concentration. We hypothesized that optimal MC application enhances photosynthetic efficiency and carbohydrate metabolism, thereby increasing yield. A pot experiment was conducted using two cultivars (HN44, HN65) with four MC concentrations (50–400 mg/L) applied at seedling (V3), flowering (R1), or both stages (V3 + R1). Dry matter, photosynthesis, carbohydrates, and yield were evaluated. MC significantly altered dry matter partitioning; 200 mg/L at seedling stage increased total dry matter in HN65 at R6. MC enhanced net photosynthetic rate and PSII efficiency in a concentration-dependent manner, particularly improving photoprotective capacity in HN65. Leaf carbohydrate accumulation was also affected. Yield gains were stage- and cultivar-specific: seedling-stage 200 mg/L increased grain weight per plant in HN65, while flowering-stage 50 mg/L was most effective for HN44. Combined applications (200–400 mg/L) produced the highest yields for both cultivars. This is the first comparative evidence that HN44 and HN65 exhibit divergent yield responses to MC timing—HN44 benefits from flowering-stage, HN65 from seedling-stage application. Optimizing MC concentration and timing enhances yield by modulating photosynthesis and assimilate partitioning in a cultivar-dependent manner.