The scarcity of phosphorus (P) makes improving phosphorus use efficiency a critical issue in crop production. Plant rhizosphere microorganisms play a vital role in increasing phosphorus bioavailability and promoting the level of plant-absorbable P in agroecosystems. In this study, Talaromyces purpurogenus SW-10 strain with efficient organic phosphate-mineralizing ability was isolated from maize rhizosphere soil. SW-10 showed efficient phytate utilization with corresponding soluble P levels of 525.43 mg/L and produced phytase in the liquid medium. The response surface methodology (RSM) analysis showed that glucose as the carbon source and (NH₄)₂SO₄ as the nitrogen source at 28 °C and pH 7.0 promoted higher mineralization of insoluble organic phosphate. When cocultivated with different genotypes of maize seedlings, SW-10 significantly increased the shoot’s dry weight by 37.93%, root’s dry weight by 31.25%, and the plant height by 13.03% for low-P sensitive inbred line 31778, while no significant change was observed in the low-P tolerance inbred line CCM454. In addition, SW-10 strain significantly increased total P-concentration in the shoots (22.4%~32.9%) and roots (3.10%~9.77%) for both inbred lines. In conclusion, the isolated T. purpurogenus SW-10 strain possesses an efficient organic phosphate-mineralizing ability and maize plant growth-promoting effect, especially for the low-P sensitive genotype that could be exploited for enhancing P availability in agriculture.

Tillage practices can directly affect soil quality, influencing soil properties, crop growth, and soil microbial community characteristics. However, the influence of long-term tillage practices on the rhizosphere bacterial community in lime concretion black soil remains largely unknown. In this study, the effects of nine-year rotary tillage (RT), no-tillage (NT), subsoiling tillage (ST), and plow tillage (PT) on soil chemical properties, microbial community structure, and correlations between bacterial communities and soil properties in the maize rhizosphere were investigated. The results revealed that the maize yield in ST and PT was higher by 10.61% and 10.26% than that in RT and by 10.25% and 9.90% than that in NT, respectively. The soil organic matter (SOM) and total nitrogen (TN) contents in NT and ST were significantly higher than those in RT and PT, whereas the available phosphorus (AP) content in ST and PT was significantly higher than that in NT and RT. The diversity and richness of the soil bacterial communities exhibited a trend of NT > RT > PT > ST. The principal component analysis revealed that the soil bacterial community differed among treatments. Linear discriminant analysis effect size (LEfSe) analysis demonstrated that Proteobacteria, Armatimonadetes, Verrucomicrobia, and Chloroflexi could serve as crucial biomarkers. Phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) results revealed that genes involved in carbon, lipid, and xenobiotic metabolism were enriched under ST and PT, whereas those involved in nitrogen and carbon fixation were enriched under NT. Besides, Proteobacteria, Verrucomicrobia, and Armatimonadetes were positively associated with AP levels and negatively associated with pH; however, Acidobacteria, Bacteroidetes, and Planctomycetes exhibited an opposite trend. Overall, ST and PT improved the soil properties and environmental suitability by increasing the bacterial keystone taxa; thus, these practices improved crop yield. These findings could enhance our understanding of the rhizosphere functional microbial community in lime concretion black soil for winter wheat–summer maize double-cropping system.

Inappropriate spatial distribution of canopy and roots limits further improvements to the grain yield of maize with increased planting density. We explored an integrated management practice called strip deep rotary with staggered planting (SRS) which includes comprehensive technology for both canopy layers and topsoil. Here, field experiments were conducted under two maize cropping systems (spring maize and summer maize) to evaluate the effect of SRS on the spatial distribution of the canopy and roots for maize under high planting density (90,000 plants ha⁻¹) and to determine the physiological factors involved in yield formation. Compared with conventional management practices (no-tillage with single planting, NTS), SRS decreased the LAI of the middle to top layers while improving the light distribution of the middle and lower layers by 72.99% and 84.78%, respectively. Meanwhile, SRS increased the root dry weight density and root sap bleeding by 51.26% and 21.77%, respectively, due to the reduction in soil bulk density by an average of 5.08% in the 0–40 cm soil layer. SRS improved the SPAD in the ear and lower leaves and maximized the LAD, which was conducive to dry matter accumulation (DMA), increasing it by 14.02–24.16% compared to that of NTS. As a result, SRS increased maize grain yield by 6.71–25.44%. These results suggest that strip deep rotary combined with staggered planting noticeably optimized the distribution of light in the canopy and reduced the soil bulk density to promote root vitality and growth, to maintain canopy longevity, and to promote the accumulation of dry matter, which eventually increased the grain yield of the maize under high planting density conditions. Therefore, SRS can be considered a better choice for the sustainable high yield of maize under high-density planting conditions in the NCP and similar areas throughout the world.

Talaromyces purpurogenus, an endophytic fungus, exhibits beneficial effects on plants during plant–fungus interactions. However, the molecular mechanisms underlying plants’ responses to T. purpurogenus under low-phosphorous (P) stress are not fully understood. In this study, we investigated the transcriptomic changes in maize with low-P-sensitive (31778) and -tolerant (CCM454) genotypes under low-P stress and its symbiotic interaction with T. purpurogenus. Its colonization enhanced plant growth and facilitated P uptake, particularly in 31778. Transcriptome sequencing revealed that 135 DEGs from CCM454 and 389 from 31778 were identified, and that only 6 DEGs were common. This suggested that CCM454 and 31778 exhibited distinct molecular responses to T. purpurogenus inoculation. GO and KEGG analysis revealed that DEGs in 31778 were associated with nicotianamine biosynthesis, organic acid metabolic process, inorganic anion transport, biosynthesis of various secondary metabolites and nitrogen metabolism. In CCM454, DEGs were associated with anthocyanin biosynthesis, diterpenoid biosynthesis and metabolic process. After T. purpurogenus inoculation, the genes associated with phosphate transporter, phosphatase, peroxidase and high-affinity nitrate transporter were upregulated in 31778, whereas AP2-EREBP-transcription factors were detected at significantly higher levels in CCM454. This study provided insights on the molecular mechanisms underlying plant–endophytic fungus symbiosis and low-P stress in maize with low-P-sensitive and -tolerant genotypes.

Drip tape layout and flow rate are crucial variables that impact the effects of drip fertigation. To investigate the influence of drip tape layout and flow rate on the soil water and nitrogen transport in summer maize in sandy tidal soil, field experiments were conducted for two years. Two drip tape layouts were set: one tape serving for two crop rows (N) and one tape serving for each crop row (E), with two levels of drip flow rate, i.e., high (2 L/h; H) and low (1.3 L/h; L). The results show that under the same drip tape layout, the lower the drip emitter flow rate, the more upright the shape of wetted soil volume. The maximum vertical and horizontal water transport distance under NL treatment was higher than that under NH, EH, and EL treatments. After surface drip fertigation, nitrate nitrogen accumulated near and at the edge of the wetted soil volume. In 2020, under NL treatment, nitrate nitrogen transported to a 55 cm soil layer, which was 22.22%, 71.42%, and 57.14% deeper than that under NH, EH, and EL treatments, respectively. In 2021, nitrate nitrogen could transport to a 60 cm soil layer in both NL and NH treatments. The maximum concentration of ammonium nitrogen was nearby the emitter. Under NL treatment, ammonium nitrogen was transported to 48 and 60 cm soil layers below the emitter in 2020 and 2021, respectively, which was deeper than that observed under NH, EH, and EL treatments. The soil inorganic nitrogen residue of the NL was lower than that of the NH, EH, and EL treatments. Compared with NH, EH, and EL treatments, the two-year maize yield under NL treatment increased by 11.09%, 13.47%, and 8.66% on average, respectively. NL treatment exhibited the highest water use efficiency and nitrogen fertilizer productivity. Therefore, NL treatment (one drip tape serving for two rows with 1.3 L/h flow rate) could promote the absorption of water and nutrients, reduce inorganic nitrogen residue, and to obtain high maize yield in sandy tidal soil.

In the Huang-Huai-Hai region, a high kernel moisture content remains a primary constraint for the mechanical harvesting of maize kernels. Recent studies have largely focused on the relationships among ear traits, meteorological factors, and kernel dehydration. However, the regulatory mechanisms underlying the influence of kernel microstructure and starch granule size distribution on dehydration characteristics remain unclear. In this study, the fast-dehydrating variety Jingnongke 728 (JNK728) and the slow-dehydrating variety Zhengdan 958 (ZD958) were selected as experimental materials to compare the varietal differences in kernel microstructure and starch granule size distribution, and to investigate their roles in regulating kernel dehydration characteristics. The results showed that JNK728 had a significantly higher kernel dehydration rate (KDR). Compared with ZD958, JNK728 exhibited average increases of 15.22% in the pre-physiological maturity dehydration rate (pre-KDR) and 97.72% in the post-physiological maturity dehydration rate (post-KDR). The higher accumulations of kernel total starch content and amylopectin content were also observed in JNK728. Kernels of JNK728 were characterized by thinner pericarp at 35 days after pollination (DAP), lower vitreousness and a higher proportion of floury endosperm. Additionally, JNK728 displayed more uniformly sized starch granules with smooth surfaces, wider intergranular spaces, and looser starch packing. Moreover, the volume, number, and surface area of large starch granules (≥10 μm) in JNK728, increased by 2.91%, 10.94%, and 4.95%, respectively. These findings enhance the understanding of the regulatory role of kernel microstructure and starch granule size distribution in dehydration characteristics, offering theoretical guidance for the development of mechanical maize kernel harvesting technologies in the Huang-Huai-Hai region.