Intercropping research interest is increasing globally due to its contribution to agriculture sustainability, crop productivity, and soil quality. To better understand the advantageous effect of intercropping, a pot and field experiment was conducted to evaluate the impact of maize-alfalfa intercropping on the plant and soil nutrient contents under nitrogen fertilization (N0 and N1 at 2.0 g pot⁻¹ and 225.0 kg hm⁻²) in Changchun, China. The results revealed that intercropping with or without nitrogen fertilizer application significantly (p < 0.05) improved the yield, biomass dry matter and plant-soil nutrient contents. The increased yield and biomass dry matter (140.7 and 268.7 g pot⁻¹) and (38% and 25%) suggested the improved efficiency of the intercropping system with nitrogen in maize. Moreover, the nutrient concentration of maize and alfalfa such as nitrogen (N), phosphorous (P), potassium (K), calcium (Ca), iron (Fe) and zinc (Zn) were also improved in the intercropping system under nitrogen fertilizer application. In general, the findings also indicated that maize-alfalfa intercropping with nitrogen fertilizer application significantly improved the soil-based N, P, K, and soil organic matter. The results suggest that the use of intercropping with reasonable nitrogen fertilizer application can improve the growth, yield, plant, and soil nutrient status.

Introduction: This study assessed the effects of S application on maize yields and soil bacterial communities across four sites with different soil types and three S application rates (0 kg ha^-1, 30 kg ha^-1, and 90 kg ha^-1).Methods: Changes in soil properties, bacterial community diversity, structure, and their contributions to maize production were evaluated post-S application treatments.Results: (1) S application decreased soil pH, increased available sulfur (AS), and boosted maize yields in all soil types. (2) Reduced Chao1 and Shannon diversity indices were observed in black soil after S application. (3) Bacterial community structure was significantly affected by S application, except in sandy soil, impacting key stone taxa abundance. (4) Black soil showed higher sensitivity to S application due to less stable bacterial community structure. (5) Soil physicochemical indicators altered by S application, such as AS and pH, mediated bacterial diversity, influencing maize yield. Organic matter (OM) had the most significant direct positive effect on yield, followed by AS and bacterial community diversity.Discussion: This study emphasizes the impact of S application on soil properties and bacterial communities in diverse soil types. Understanding these mechanisms can guide precision S application practices for maize yield regulation.

Sulfur (S) is an essential nutrient element for crops and plays an important role in regulating and controlling the growth and development of plants. However, there are few studies on the effects of inorganic S fertilizer on soil bacterial community structure and the relationship between these communities and soil properties in the main corn producing areas of Jilin Province, China. This study evaluated the effects of applying different levels of ammonium sulfate fertilizers (S0, S30, S90, S150) on soil properties and bacterial communities. The results revealed that S fertilizer treatment increased the available sulfur (AS) content in soil and reduced soil pH, soil organic matter (OM) as compared with S0 treatment. S fertilizer treatment increased the bacterial richness of black soil (Chao1) and reduced the bacterial richness of sandy soil. In addition, the application of S fertilizer significantly changed the soil bacterial community structure and it was revealed that S fertilizer have different effect on black and sandy soil bacterial communities. Partial Least Squares Discriminant Analysis (PLS-DA) indicated that the S treatment changed the structure of bacterial community and Redundancy analysis (RDA) showed that soil pH and AS were major variables affecting the structure of soil bacterial community.