Fertilization is a key management practice for maintaining or improving soil fertility and ensuring grain yield in agro-ecosystems. Nevertheless, as a low-yield soil, how fertilization strategies impact the status of albic soil physical and chemical properties, biological activity, and crop yield are poorly understood. Through a two-year positioning experiment, the albic soil fertility characteristics (physical, chemical, and biological) and changes in maize yield under different fertilization were studied. Three treatments were established: (1) conventional fertilization (chemical fertilizer) (T1), (2) optimized fertilization 1 (low amount of organic fertilizer + chemical fertilizer) (T2), and (3) optimized fertilization 2 (high amount of organic fertilizer + chemical fertilizer) (T3). The results indicated that, compared with T1, the soil bulk density of T2 and T3 treatments decreased, the average solid phase ratio of soil decreased by 8.2%, and the average liquid and gas phase ratios increased by 7.2% and 10.2%, respectively. The soil organic matter (SOM) and soil organic carbon storage (SOCS) under treatment of optimized fertilization were significantly higher than under T1, with an average increase of 10.1% for SOM and 8.8% for SOCS, respectively. T3 significantly increased the contents of alkali-hydrolyzable nitrogen, available phosphorus, and available potassium, while different fertilizations had little effect on soil pH. T2 and T3 significantly increased activities of soil urease, sucrase, phosphatase, and catalase, with an average increase of 33.7%, 56.9%, 32.0%, and 6.7%, respectively. The numbers of soil bacteria and actinomycetes under T3 increased significantly by 30.2% and 22.0% compared to T1, while the number of fungi decreased by 6.7%. The total number of soil microorganisms increased significantly by 29.0% of T3, and the proportion of soil bacteria to the total number of microorganisms increased, while the proportion of fungi and actinomycetes decreased. The maize yield of T3 was significantly higher than under other treatments, with an increase of 2368.5 kg/ha compared to T1. Correlation analysis showed that the contents of available nutrients and organic matter, the numbers of soil bacteria and actinomycetes, and the activities of soil urease and phosphatase had the most significant impact on maize yield. The optimized fertilization, which was the organic fertilizer combined with chemical fertilizer, can improve the physical properties of albic soil, increase soil organic matter content, organic carbon storage, available nutrient content, and soil biological activity, also for maize yield. Therefore, the optimized fertilization in albic soil of Northeast China is a promising and important management option for improved soil quality and grain yield. This work provides a theoretical basis and technical reference for efficient fertilization.

This research targets straw return in Farm 852’s albic soil, China. The soil is nutrient-poor with few microbes and slow straw decomposition. Through fixed-point sampling and bacterial screening, an actinomycete consortium consisting of four strains was assembled, and two of them were identified as new actinomycetes. After 7 days of fermentation, the lignocellulose degradation rates of this consortium outstripped those of single strains, with cellulose degraded at 69.07%, hemicellulose at 64.98%, and lignin at 68.95%. FTIR, XRD, and SEM verified the damage inflicted on the straw structure. Lab simulations found group D (with the consortium) had a higher straw weight loss rate than group C (with commercialized microbial agents) and controls. The compound actinomycetes stepped up the bacterial abundance with the passage of time. In contrast, their effect on fungal abundance was hardly noticeable, but they had markedly ameliorated the soil fertility. These findings prove that the microbial consortium effectively accelerates straw decomposition and boosts soil microbe abundance and fertility in albic soil. It shows great potential for straw return and provides a microbial solution for this field.

Nitrogen (N) fertilizer incorporation of efficiency enhancer is a well-established practice aiming at reducing N loss while enhancing crop yield. However, the effect of different kinds of fertilizer efficiency enhancer on N use efficiency (NUE) and gas loss are rarely compared and poorly comprehended. Here, we conducted a field experiment involving the combination of urease and nitrification inhibitor (NI), the biological inhibitor eugenol (DE) and the bioploymer poly-glutamic acid (PG) and their combinations (NI + PG, NI + DE, PG + DE) to evaluate their effects on crop yield, NUE, NH3 volatilization and greenhouse gas emissions (GHGs). Results indicated that NI, DE, PG and their combinations significantly enhanced the crop yield, N uptake and NUE. NI, DE and PG are all effective in reducing NH₃ volatilization and N₂O emission, averagely decreased by 11.13%, 6.83%, 8.29%, respectively, and by 11.15%, 4.32%, 8.35%, respectively, while have no significant effects on CO₂-C and CH₄-C fluxes, except PG significantly increases CO₂-C emission and thus global warming potential. The combination of these three efficiency enhancers has no multiply effect on maize yield, NUE and gas loss. These findings help to screen the fertilizer efficiency enhancer that can be more effectively utilized in agricultural practices and contribute to their application strategies within agricultural systems.

Poly-γ-glutamic acid (γ-PGA) significantly promotes the fertilizer N uptake efficiency of crops and evidently affects soil available N (nitrate, ammonium and glutamate) status. As an adaptive strategy to forage N, root morphology responds variably to soil available N dynamics. Detailed knowledge of how root morphology responds to γ-PGA remains unexplored. A pot trial was conducted to investigate the response of root morphological traits to γ-PGA when applied with CO(NH₂)₂ or (NH₄)₂SO₄. The results showed that γ-PGA significantly improved the dry weight, total carbon and total nitrogen content of roots, and with a higher improvement with CO(NH₂)₂ compared to (NH₄)₂SO₄. γ-PGA significantly increased the root length, total surface area, tips and forks with CO(NH₂)₂. Contrarily, γ-PGA significantly reduced root length, specific root length, specific root area, root volume, tips and forks with (NH₄)₂SO₄, with its inhibition on root growth mainly caused by the high ammonium content in soil. In conclusion, γ-PGA gives opposite effects on root morphological traits when applied with CO(NH₂)₂ or (NH₄)₂SO₄. This finding provides a new insight to reveal the promotion mechanism of γ-PGA on plant N acquisition in the rhizosphere and offers a practical reference for optimizing γ-PGA and fertilizer application management.

Soils with an albic horizon (characterized by a bleached, nutrient-poor eluvial layer), classified primarily as Albic Planosols and associated groups (e.g., Albic Luvisols and Retisols) in the World Reference Base for Soil Resources (WRB), are widespread in Northeast China and suffer from inherent poor nutrient availability and low crop productivity. The present study aimed to evaluate the efficacy of novel microbial–enzyme composite biofertilizers in ameliorating Albic soils. This comprehensive assessment investigated their effects on soil nutrient availability, microbial community structure, and the activities of key enzymes involved in nutrient cycling (e.g., dehydrogenase and phosphatase). Concurrently, the impact on maize crop performance was determined by measuring changes in agronomic traits, including chlorophyll content, stem diameter, and final grain yield. A field experiment was conducted in Heilongjiang Province during the 2023 maize growing season using a randomized block design with six treatments: CF (conventional chemical fertilizer, 330 kg·ha⁻¹ NPK), OF (chemical fertilizer + 1500 kg·ha⁻¹ organic carrier), BF1 (OF + 75 kg·ha⁻¹ marine actinomycetes), BF2 (OF + 75 kg·ha⁻¹ actinomycetes + 45 kg·ha⁻¹ phytase), BF3 (OF + 75 kg·ha⁻¹ actinomycetes + 45 kg·ha⁻¹ mycorrhizal fungi + 45 kg·ha⁻¹ phytase), and BF4 (OF + 75 kg·ha⁻¹ actinomycetes + 45 kg·ha⁻¹ mycorrhizal fungi + 45 kg·ha⁻¹ phytase + 45 kg·ha⁻¹ β–glucosidase). The results showed that biofertilizers significantly increased microbial abundance and enzyme activity. The integrated treatment BF4 notably enhanced topsoil fungal abundance by 188.1% and dehydrogenase activity in the 0–20 cm layer, while also increasing available phosphorus by 92.6% at maturity. Although BF4 improved soil properties the most, BF3 produced the highest maize yield—boosting grain output by 18.3% over CF—and improved stem diameter and chlorophyll content. Strong correlations between microbial parameters and enzyme activities indicated a nutrient-cycling mechanism driven by microorganisms, with topsoil fungal abundance positively linked to alkaline phosphatase activity (r = 0.72) and subsoil bacterial abundance associated with available phosphorus (r = 0.65), demonstrating microbial–mediated carbon–phosphorus coupling. In conclusion, microbial–enzyme biofertilizers, particularly BF4, provide a sustainable strategy for enhancing Albic soil fertility and crop productivity.

Albic soil is a typical low-yield and problematic soil in Northeast China, which severely restricts crop growth and yield. Through a three-year field experiment in the albic soil of China, soil three-phase ratio, soil bulk density (soil BD), soil total porosity (soil TP), size distribution and water stability of soil aggregates, and changes in maize yield under crop rotations were studied. The following three treatments were established: conventional fertilization (T0), conventional fertilization + soil amendment (T1), and conventional fertilization + soil amendment + bio-organic fertilizer (T2). The results indicated that, compared with T0, the soil three-phase ratio deviation value (R) of T1 and T2 decreased by 23.69–74.94%, and the generalized soil structure index (GSSI) increased by 4.75–15.41% in soil layers of 0–20 cm and 20–40 cm. Soil BD and soil TP changed significantly in the soil layer of 20–40 cm under treatment of T2 (decreased 12.82% and increased 18.31%, respectively). Content of aggregates >0.25 mm (R_0.25) increased significantly in the soil layer of 0–20 cm, with increases of 13.71% and 23.21% under treatments of T1 and T2. The mean weight diameter (MWD) and geometric mean diameter (GMD) increased significantly under treatment of T2. Compared with T0, maize yield increased 13.45% and 18.85% under treatments of T1 and T2. Correlation analysis showed that maize yield was significantly correlated with soil physical indexes and aggregate stability. In summary, the combined application of soil amendments and bio-organic fertilizer is not only important for albic soil improvement, but also crucial to stabilize the crop production capacity in albic soil regions.